Commit Graph

17535 Commits

Author SHA1 Message Date
Matthew Wilcox (Oracle)
0e499ed3d7 filemap: Return only folios from find_get_entries()
The callers have all been converted to work on folios, so convert
find_get_entries() to return a batch of folios instead of pages.
We also now return multiple large folios in a single call.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-01-08 00:28:41 -05:00
Matthew Wilcox (Oracle)
25d6a23e8d filemap: Convert filemap_get_read_batch() to use a folio_batch
This change ripples all the way through the filemap_read() call chain and
removes a lot of messing about converting folios to pages and back again.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-08 00:28:41 -05:00
Matthew Wilcox (Oracle)
d996fc7f61 filemap: Convert filemap_read() to use a folio
We know the pagevec always contains folios, but use page_folio() anyway
instead of casting.  Removes a few calls to legacy functions.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-08 00:28:41 -05:00
Matthew Wilcox (Oracle)
78f426608f truncate: Add invalidate_complete_folio2()
Convert invalidate_complete_page2() to invalidate_complete_folio2().
Use filemap_free_folio() to free the page instead of calling ->freepage
manually.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-08 00:28:41 -05:00
Matthew Wilcox (Oracle)
fae9bc4a90 truncate: Convert invalidate_inode_pages2_range() to use a folio
If we're going to unmap a folio, we have to be sure to unmap the entire
folio, not just the part of it which lies after the search index.

We cannot yet remove the struct page from invalidate_inode_pages2_range()
because the page pointer in the pvec might be a shadow/dax/swap entry
instead of actually a page.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-08 00:28:41 -05:00
Matthew Wilcox (Oracle)
ccbbf761d4 truncate: Skip known-truncated indices
If we've truncated an entire folio, we can skip over all the indices
covered by this folio.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-08 00:28:41 -05:00
Matthew Wilcox (Oracle)
1e84a3d997 truncate,shmem: Add truncate_inode_folio()
Convert all callers of truncate_inode_page() to call
truncate_inode_folio() instead, and move the declaration to mm/internal.h.
Move the assertion that the caller is not passing in a tail page to
generic_error_remove_page().  We can't entirely remove the struct page
from the callers yet because the page pointer in the pvec might be a
shadow/dax/swap entry instead of actually a page.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-08 00:28:41 -05:00
Matthew Wilcox (Oracle)
7b774aab79 shmem: Convert part of shmem_undo_range() to use a folio
find_lock_entries() never returns tail pages.  We cannot use page_folio()
here as the pagevec may also contain swap entries, so simply cast for
now.  This is an intermediate step which will be fully removed by the
end of this series.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-08 00:28:41 -05:00
Matthew Wilcox (Oracle)
3506659e18 mm: Add unmap_mapping_folio()
Convert both callers of unmap_mapping_page() to call unmap_mapping_folio()
instead.  Also move zap_details from linux/mm.h to mm/memory.c

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-08 00:28:32 -05:00
Matthew Wilcox (Oracle)
07f910f9b7 mm: Remove slab from struct page
All members of struct slab can now be removed from struct page.
This shrinks the definition of struct page by 30 LOC, making
it easier to understand.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2022-01-06 18:06:58 +01:00
Hyeonggon Yoo
b01af5c0b0 mm/slob: Remove unnecessary page_mapcount_reset() function call
After commit 401fb12c68 ("mm/sl*b: Differentiate struct slab fields by
sl*b implementations"), we can reorder fields of struct slab depending
on slab allocator.

For now, page_mapcount_reset() is called because page->_mapcount and
slab->units have same offset. But this is not necessary for struct slab.
Use unused field for units instead.

Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Link: https://lore.kernel.org/r/20211212065241.GA886691@odroid
2022-01-06 12:27:28 +01:00
Matthew Wilcox (Oracle)
c5e97ed154 bootmem: Use page->index instead of page->freelist
page->freelist is for the use of slab.  Using page->index is the same
set of bits as page->freelist, and by using an integer instead of a
pointer, we can avoid casts.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: <x86@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
2022-01-06 12:27:03 +01:00
Matthew Wilcox (Oracle)
ffedd09fa9 zsmalloc: Stop using slab fields in struct page
The ->freelist and ->units members of struct page are for the use of
slab only.  I'm not particularly familiar with zsmalloc, so generate the
same code by using page->index to store 'page' (page->index and
page->freelist are at the same offset in struct page).  This should be
cleaned up properly at some point by somebody who is familiar with
zsmalloc.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
2022-01-06 12:27:03 +01:00
Vlastimil Babka
9c01e9af17 mm/slub: Define struct slab fields for CONFIG_SLUB_CPU_PARTIAL only when enabled
The fields 'next' and 'slabs' are only used when CONFIG_SLUB_CPU_PARTIAL
is enabled. We can put their definition to #ifdef to prevent accidental
use when disabled.

Currenlty show_slab_objects() and slabs_cpu_partial_show() contain code
accessing the slabs field that's effectively dead with
CONFIG_SLUB_CPU_PARTIAL=n through the wrappers slub_percpu_partial() and
slub_percpu_partial_read_once(), but to prevent a compile error, we need
to hide all this code behind #ifdef.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
2022-01-06 12:26:53 +01:00
Vlastimil Babka
662188c3a2 mm/slub: Simplify struct slab slabs field definition
Before commit b47291ef02 ("mm, slub: change percpu partial accounting
from objects to pages") we had to fit two integer fields into a native
word size, so we used short int on 32-bit and int on 64-bit via #ifdef.
After that commit there is only one integer field, so we can simply
define it as int everywhere.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Roman Gushchin <guro@fb.com>
2022-01-06 12:26:45 +01:00
Vlastimil Babka
401fb12c68 mm/sl*b: Differentiate struct slab fields by sl*b implementations
With a struct slab definition separate from struct page, we can go
further and define only fields that the chosen sl*b implementation uses.
This means everything between __page_flags and __page_refcount
placeholders now depends on the chosen CONFIG_SL*B. Some fields exist in
all implementations (slab_list) but can be part of a union in some, so
it's simpler to repeat them than complicate the definition with ifdefs
even more.

The patch doesn't change physical offsets of the fields, although it
could be done later - for example it's now clear that tighter packing in
SLOB could be possible.

This should also prevent accidental use of fields that don't exist in
given implementation. Before this patch virt_to_cache() and
cache_from_obj() were visible for SLOB (albeit not used), although they
rely on the slab_cache field that isn't set by SLOB. With this patch
it's now a compile error, so these functions are now hidden behind
an #ifndef CONFIG_SLOB.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
Tested-by: Marco Elver <elver@google.com> # kfence
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: <kasan-dev@googlegroups.com>
2022-01-06 12:26:29 +01:00
Vlastimil Babka
8dae0cfed5 mm/kfence: Convert kfence_guarded_alloc() to struct slab
The function sets some fields that are being moved from struct page to
struct slab so it needs to be converted.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: <kasan-dev@googlegroups.com>
2022-01-06 12:26:29 +01:00
Matthew Wilcox (Oracle)
6e48a966df mm/kasan: Convert to struct folio and struct slab
KASAN accesses some slab related struct page fields so we need to
convert it to struct slab. Some places are a bit simplified thanks to
kasan_addr_to_slab() encapsulating the PageSlab flag check through
virt_to_slab().  When resolving object address to either a real slab or
a large kmalloc, use struct folio as the intermediate type for testing
the slab flag to avoid unnecessary implicit compound_head().

[ vbabka@suse.cz: use struct folio, adjust to differences in previous
  patches ]

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Tested-by: Hyeongogn Yoo <42.hyeyoo@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: <kasan-dev@googlegroups.com>
2022-01-06 12:26:14 +01:00
Matthew Wilcox (Oracle)
50757018b4 mm/slob: Convert SLOB to use struct slab and struct folio
Use struct slab throughout the slob allocator. Where non-slab page can
appear use struct folio instead of struct page.

[ vbabka@suse.cz: don't introduce wrappers for PageSlobFree in mm/slab.h
  just for the single callers being wrappers in mm/slob.c ]

[ Hyeonggon Yoo <42.hyeyoo@gmail.com>: fix NULL pointer deference ]

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
2022-01-06 12:26:14 +01:00
Vlastimil Babka
4b5f8d9a89 mm/memcg: Convert slab objcgs from struct page to struct slab
page->memcg_data is used with MEMCG_DATA_OBJCGS flag only for slab pages
so convert all the related infrastructure to struct slab. Also use
struct folio instead of struct page when resolving object pointers.

This is not just mechanistic changing of types and names. Now in
mem_cgroup_from_obj() we use folio_test_slab() to decide if we interpret
the folio as a real slab instead of a large kmalloc, instead of relying
on MEMCG_DATA_OBJCGS bit that used to be checked in page_objcgs_check().
Similarly in memcg_slab_free_hook() where we can encounter
kmalloc_large() pages (here the folio slab flag check is implied by
virt_to_slab()). As a result, page_objcgs_check() can be dropped instead
of converted.

To avoid include cycles, move the inline definition of slab_objcgs()
from memcontrol.h to mm/slab.h.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <cgroups@vger.kernel.org>
2022-01-06 12:26:14 +01:00
Vlastimil Babka
40f3bf0cb0 mm: Convert struct page to struct slab in functions used by other subsystems
KASAN, KFENCE and memcg interact with SLAB or SLUB internals through
functions nearest_obj(), obj_to_index() and objs_per_slab() that use
struct page as parameter. This patch converts it to struct slab
including all callers, through a coccinelle semantic patch.

// Options: --include-headers --no-includes --smpl-spacing include/linux/slab_def.h include/linux/slub_def.h mm/slab.h mm/kasan/*.c mm/kfence/kfence_test.c mm/memcontrol.c mm/slab.c mm/slub.c
// Note: needs coccinelle 1.1.1 to avoid breaking whitespace

@@
@@

-objs_per_slab_page(
+objs_per_slab(
 ...
 )
 { ... }

@@
@@

-objs_per_slab_page(
+objs_per_slab(
 ...
 )

@@
identifier fn =~ "obj_to_index|objs_per_slab";
@@

 fn(...,
-   const struct page *page
+   const struct slab *slab
    ,...)
 {
<...
(
- page_address(page)
+ slab_address(slab)
|
- page
+ slab
)
...>
 }

@@
identifier fn =~ "nearest_obj";
@@

 fn(...,
-   struct page *page
+   const struct slab *slab
    ,...)
 {
<...
(
- page_address(page)
+ slab_address(slab)
|
- page
+ slab
)
...>
 }

@@
identifier fn =~ "nearest_obj|obj_to_index|objs_per_slab";
expression E;
@@

 fn(...,
(
- slab_page(E)
+ E
|
- virt_to_page(E)
+ virt_to_slab(E)
|
- virt_to_head_page(E)
+ virt_to_slab(E)
|
- page
+ page_slab(page)
)
  ,...)

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Julia Lawall <julia.lawall@inria.fr>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <kasan-dev@googlegroups.com>
Cc: <cgroups@vger.kernel.org>
2022-01-06 12:26:13 +01:00
Vlastimil Babka
dd35f71a1d mm/slab: Finish struct page to struct slab conversion
Change cache_free_alien() to use slab_nid(virt_to_slab()). Otherwise
just update of comments and some remaining variable names.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
2022-01-06 12:26:10 +01:00
Vlastimil Babka
7981e67efb mm/slab: Convert most struct page to struct slab by spatch
The majority of conversion from struct page to struct slab in SLAB
internals can be delegated to a coccinelle semantic patch. This includes
renaming of variables with 'page' in name to 'slab', and similar.

Big thanks to Julia Lawall and Luis Chamberlain for help with
coccinelle.

// Options: --include-headers --no-includes --smpl-spacing mm/slab.c
// Note: needs coccinelle 1.1.1 to avoid breaking whitespace, and ocaml for the
// embedded script

// build list of functions for applying the next rule
@initialize:ocaml@
@@

let ok_function p =
  not (List.mem (List.hd p).current_element ["kmem_getpages";"kmem_freepages"])

// convert the type in selected functions
@@
position p : script:ocaml() { ok_function p };
@@

- struct page@p
+ struct slab

@@
@@

-PageSlabPfmemalloc(page)
+slab_test_pfmemalloc(slab)

@@
@@

-ClearPageSlabPfmemalloc(page)
+slab_clear_pfmemalloc(slab)

@@
@@

obj_to_index(
 ...,
- page
+ slab_page(slab)
,...)

// for all functions, change any "struct slab *page" parameter to "struct slab
// *slab" in the signature, and generally all occurences of "page" to "slab" in
// the body - with some special cases.
@@
identifier fn;
expression E;
@@

 fn(...,
-   struct slab *page
+   struct slab *slab
    ,...)
 {
<...
(
- int page_node;
+ int slab_node;
|
- page_node
+ slab_node
|
- page_slab(page)
+ slab
|
- page_address(page)
+ slab_address(slab)
|
- page_size(page)
+ slab_size(slab)
|
- page_to_nid(page)
+ slab_nid(slab)
|
- virt_to_head_page(E)
+ virt_to_slab(E)
|
- page
+ slab
)
...>
 }

// rename a function parameter
@@
identifier fn;
expression E;
@@

 fn(...,
-   int page_node
+   int slab_node
    ,...)
 {
<...
- page_node
+ slab_node
...>
 }

// functions converted by previous rules that were temporarily called using
// slab_page(E) so we want to remove the wrapper now that they accept struct
// slab ptr directly
@@
identifier fn =~ "index_to_obj";
expression E;
@@

 fn(...,
- slab_page(E)
+ E
 ,...)

// functions that were returning struct page ptr and now will return struct
// slab ptr, including slab_page() wrapper removal
@@
identifier fn =~ "cache_grow_begin|get_valid_first_slab|get_first_slab";
expression E;
@@

 fn(...)
 {
<...
- slab_page(E)
+ E
...>
 }

// rename any former struct page * declarations
@@
@@

struct slab *
-page
+slab
;

// all functions (with exceptions) with a local "struct slab *page" variable
// that will be renamed to "struct slab *slab"
@@
identifier fn !~ "kmem_getpages|kmem_freepages";
expression E;
@@

 fn(...)
 {
<...
(
- page_slab(page)
+ slab
|
- page_to_nid(page)
+ slab_nid(slab)
|
- kasan_poison_slab(page)
+ kasan_poison_slab(slab_page(slab))
|
- page_address(page)
+ slab_address(slab)
|
- page_size(page)
+ slab_size(slab)
|
- page->pages
+ slab->slabs
|
- page = virt_to_head_page(E)
+ slab = virt_to_slab(E)
|
- virt_to_head_page(E)
+ virt_to_slab(E)
|
- page
+ slab
)
...>
 }

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Julia Lawall <julia.lawall@inria.fr>
Cc: Luis Chamberlain <mcgrof@kernel.org>
2022-01-06 12:26:02 +01:00
Vlastimil Babka
42c0faac31 mm/slab: Convert kmem_getpages() and kmem_freepages() to struct slab
These functions sit at the boundary to page allocator. Also use folio
internally to avoid extra compound_head() when dealing with page flags.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
2022-01-06 12:26:02 +01:00
Vlastimil Babka
c2092c1206 mm/slub: Finish struct page to struct slab conversion
Update comments mentioning pages to mention slabs where appropriate.
Also some goto labels.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
2022-01-06 12:26:02 +01:00
Vlastimil Babka
bb192ed9aa mm/slub: Convert most struct page to struct slab by spatch
The majority of conversion from struct page to struct slab in SLUB
internals can be delegated to a coccinelle semantic patch. This includes
renaming of variables with 'page' in name to 'slab', and similar.

Big thanks to Julia Lawall and Luis Chamberlain for help with
coccinelle.

// Options: --include-headers --no-includes --smpl-spacing include/linux/slub_def.h mm/slub.c
// Note: needs coccinelle 1.1.1 to avoid breaking whitespace, and ocaml for the
// embedded script

// build list of functions to exclude from applying the next rule
@initialize:ocaml@
@@

let ok_function p =
  not (List.mem (List.hd p).current_element ["nearest_obj";"obj_to_index";"objs_per_slab_page";"__slab_lock";"__slab_unlock";"free_nonslab_page";"kmalloc_large_node"])

// convert the type from struct page to struct page in all functions except the
// list from previous rule
// this also affects struct kmem_cache_cpu, but that's ok
@@
position p : script:ocaml() { ok_function p };
@@

- struct page@p
+ struct slab

// in struct kmem_cache_cpu, change the name from page to slab
// the type was already converted by the previous rule
@@
@@

struct kmem_cache_cpu {
...
-struct slab *page;
+struct slab *slab;
...
}

// there are many places that use c->page which is now c->slab after the
// previous rule
@@
struct kmem_cache_cpu *c;
@@

-c->page
+c->slab

@@
@@

struct kmem_cache {
...
- unsigned int cpu_partial_pages;
+ unsigned int cpu_partial_slabs;
...
}

@@
struct kmem_cache *s;
@@

- s->cpu_partial_pages
+ s->cpu_partial_slabs

@@
@@

static void
- setup_page_debug(
+ setup_slab_debug(
 ...)
 {...}

@@
@@

- setup_page_debug(
+ setup_slab_debug(
 ...);

// for all functions (with exceptions), change any "struct slab *page"
// parameter to "struct slab *slab" in the signature, and generally all
// occurences of "page" to "slab" in the body - with some special cases.

@@
identifier fn !~ "free_nonslab_page|obj_to_index|objs_per_slab_page|nearest_obj";
@@
 fn(...,
-   struct slab *page
+   struct slab *slab
    ,...)
 {
<...
- page
+ slab
...>
 }

// similar to previous but the param is called partial_page
@@
identifier fn;
@@

 fn(...,
-   struct slab *partial_page
+   struct slab *partial_slab
    ,...)
 {
<...
- partial_page
+ partial_slab
...>
 }

// similar to previous but for functions that take pointer to struct page ptr
@@
identifier fn;
@@

 fn(...,
-   struct slab **ret_page
+   struct slab **ret_slab
    ,...)
 {
<...
- ret_page
+ ret_slab
...>
 }

// functions converted by previous rules that were temporarily called using
// slab_page(E) so we want to remove the wrapper now that they accept struct
// slab ptr directly
@@
identifier fn =~ "slab_free|do_slab_free";
expression E;
@@

 fn(...,
- slab_page(E)
+ E
  ,...)

// similar to previous but for another pattern
@@
identifier fn =~ "slab_pad_check|check_object";
@@

 fn(...,
- folio_page(folio, 0)
+ slab
  ,...)

// functions that were returning struct page ptr and now will return struct
// slab ptr, including slab_page() wrapper removal
@@
identifier fn =~ "allocate_slab|new_slab";
expression E;
@@

 static
-struct slab *
+struct slab *
 fn(...)
 {
<...
- slab_page(E)
+ E
...>
 }

// rename any former struct page * declarations
@@
@@

struct slab *
(
- page
+ slab
|
- partial_page
+ partial_slab
|
- oldpage
+ oldslab
)
;

// this has to be separate from previous rule as page and page2 appear at the
// same line
@@
@@

struct slab *
-page2
+slab2
;

// similar but with initial assignment
@@
expression E;
@@

struct slab *
(
- page
+ slab
|
- flush_page
+ flush_slab
|
- discard_page
+ slab_to_discard
|
- page_to_unfreeze
+ slab_to_unfreeze
)
= E;

// convert most of struct page to struct slab usage inside functions (with
// exceptions), including specific variable renames
@@
identifier fn !~ "nearest_obj|obj_to_index|objs_per_slab_page|__slab_(un)*lock|__free_slab|free_nonslab_page|kmalloc_large_node";
expression E;
@@

 fn(...)
 {
<...
(
- int pages;
+ int slabs;
|
- int pages = E;
+ int slabs = E;
|
- page
+ slab
|
- flush_page
+ flush_slab
|
- partial_page
+ partial_slab
|
- oldpage->pages
+ oldslab->slabs
|
- oldpage
+ oldslab
|
- unsigned int nr_pages;
+ unsigned int nr_slabs;
|
- nr_pages
+ nr_slabs
|
- unsigned int partial_pages = E;
+ unsigned int partial_slabs = E;
|
- partial_pages
+ partial_slabs
)
...>
 }

// this has to be split out from the previous rule so that lines containing
// multiple matching changes will be fully converted
@@
identifier fn !~ "nearest_obj|obj_to_index|objs_per_slab_page|__slab_(un)*lock|__free_slab|free_nonslab_page|kmalloc_large_node";
@@

 fn(...)
 {
<...
(
- slab->pages
+ slab->slabs
|
- pages
+ slabs
|
- page2
+ slab2
|
- discard_page
+ slab_to_discard
|
- page_to_unfreeze
+ slab_to_unfreeze
)
...>
 }

// after we simply changed all occurences of page to slab, some usages need
// adjustment for slab-specific functions, or use slab_page() wrapper
@@
identifier fn !~ "nearest_obj|obj_to_index|objs_per_slab_page|__slab_(un)*lock|__free_slab|free_nonslab_page|kmalloc_large_node";
@@

 fn(...)
 {
<...
(
- page_slab(slab)
+ slab
|
- kasan_poison_slab(slab)
+ kasan_poison_slab(slab_page(slab))
|
- page_address(slab)
+ slab_address(slab)
|
- page_size(slab)
+ slab_size(slab)
|
- PageSlab(slab)
+ folio_test_slab(slab_folio(slab))
|
- page_to_nid(slab)
+ slab_nid(slab)
|
- compound_order(slab)
+ slab_order(slab)
)
...>
 }

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Julia Lawall <julia.lawall@inria.fr>
Cc: Luis Chamberlain <mcgrof@kernel.org>
2022-01-06 12:26:02 +01:00
Matthew Wilcox (Oracle)
01b34d1631 mm/slub: Convert pfmemalloc_match() to take a struct slab
Preparatory for mass conversion. Use the new slab_test_pfmemalloc()
helper.  As it doesn't do VM_BUG_ON(!PageSlab()) we no longer need the
pfmemalloc_match_unsafe() variant.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
2022-01-06 12:26:02 +01:00
Vlastimil Babka
4020b4a226 mm/slub: Convert __free_slab() to use struct slab
__free_slab() is on the boundary of distinguishing struct slab and
struct page so start with struct slab but convert to folio for working
with flags and folio_page() to call functions that require struct page.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
2022-01-06 12:26:01 +01:00
Vlastimil Babka
45387b8c14 mm/slub: Convert alloc_slab_page() to return a struct slab
Preparatory, callers convert back to struct page for now.

Also move setting page flags to alloc_slab_page() where we still operate
on a struct page. This means the page->slab_cache pointer is now set
later than the PageSlab flag, which could theoretically confuse some pfn
walker assuming PageSlab means there would be a valid cache pointer. But
as the code had no barriers and used __set_bit() anyway, it could have
happened already, so there shouldn't be such a walker.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
2022-01-06 12:26:01 +01:00
Matthew Wilcox (Oracle)
fb012e278d mm/slub: Convert print_page_info() to print_slab_info()
Improve the type safety and prepare for further conversion. For flags
access, convert to folio internally.

[ vbabka@suse.cz: access flags via folio_flags() ]

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
2022-01-06 12:26:01 +01:00
Vlastimil Babka
0393895b09 mm/slub: Convert __slab_lock() and __slab_unlock() to struct slab
These functions operate on the PG_locked page flag, but make them accept
struct slab to encapsulate this implementation detail.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
2022-01-06 12:26:01 +01:00
Matthew Wilcox (Oracle)
d835eef4fc mm/slub: Convert kfree() to use a struct slab
Convert kfree(), kmem_cache_free() and ___cache_free() to resolve object
addresses to struct slab, using folio as intermediate step where needed.
Keep passing the result as struct page for now in preparation for mass
conversion of internal functions.

[ vbabka@suse.cz: Use folio as intermediate step when checking for
  large kmalloc pages, and when freeing them - rename
  free_nonslab_page() to free_large_kmalloc() that takes struct folio ]

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
2022-01-06 12:25:57 +01:00
Matthew Wilcox (Oracle)
cc465c3b23 mm/slub: Convert detached_freelist to use a struct slab
This gives us a little bit of extra typesafety as we know that nobody
called virt_to_page() instead of virt_to_head_page().

[ vbabka@suse.cz: Use folio as intermediate step when filtering out
  large kmalloc pages ]

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
2022-01-06 12:25:51 +01:00
Matthew Wilcox (Oracle)
0b3eb091d5 mm: Convert check_heap_object() to use struct slab
Ensure that we're not seeing a tail page inside __check_heap_object() by
converting to a slab instead of a page.  Take the opportunity to mark
the slab as const since we're not modifying it.  Also move the
declaration of __check_heap_object() to mm/slab.h so it's not available
to the wider kernel.

[ vbabka@suse.cz: in check_heap_object() only convert to struct slab for
  actual PageSlab pages; use folio as intermediate step instead of page ]

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
2022-01-06 12:25:51 +01:00
Matthew Wilcox (Oracle)
7213230af5 mm: Use struct slab in kmem_obj_info()
All three implementations of slab support kmem_obj_info() which reports
details of an object allocated from the slab allocator.  By using the
slab type instead of the page type, we make it obvious that this can
only be called for slabs.

[ vbabka@suse.cz: also convert the related kmem_valid_obj() to folios ]

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
2022-01-06 12:25:51 +01:00
Matthew Wilcox (Oracle)
0c24811b12 mm: Convert __ksize() to struct slab
In SLUB, use folios, and struct slab to access slab_cache field.
In SLOB, use folios to properly resolve pointers beyond
PAGE_SIZE offset of the object.

[ vbabka@suse.cz: use folios, and only convert folio_test_slab() == true
  folios to struct slab ]

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Roman Gushchin <guro@fb.com>
2022-01-06 12:25:51 +01:00
Matthew Wilcox (Oracle)
82c1775dc1 mm: Convert virt_to_cache() to use struct slab
This function is entirely self-contained, so can be converted from page
to slab.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
2022-01-06 12:25:41 +01:00
Matthew Wilcox (Oracle)
b918653b4f mm: Convert [un]account_slab_page() to struct slab
Convert the parameter of these functions to struct slab instead of
struct page and drop _page from the names. For now their callers just
convert page to slab.

[ vbabka@suse.cz: replace existing functions instead of calling them ]

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Roman Gushchin <guro@fb.com>
2022-01-06 12:25:40 +01:00
Matthew Wilcox (Oracle)
d122019bf0 mm: Split slab into its own type
Make struct slab independent of struct page. It still uses the
underlying memory in struct page for storing slab-specific data, but
slab and slub can now be weaned off using struct page directly.  Some of
the wrapper functions (slab_address() and slab_order()) still need to
cast to struct folio, but this is a significant disentanglement.

[ vbabka@suse.cz: Rebase on folios, use folio instead of page where
  possible.

  Do not duplicate flags field in struct slab, instead make the related
  accessors go through slab_folio(). For testing pfmemalloc use the
  folio_*_active flag accessors directly so the PageSlabPfmemalloc
  wrappers can be removed later.

  Make folio_slab() expect only folio_test_slab() == true folios and
  virt_to_slab() return NULL when folio_test_slab() == false.

  Move struct slab to mm/slab.h.

  Don't represent with struct slab pages that are not true slab pages,
  but just a compound page obtained directly rom page allocator (with
  large kmalloc() for SLUB and SLOB). ]

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Roman Gushchin <guro@fb.com>
2022-01-06 12:25:40 +01:00
Vlastimil Babka
ae16d059f8 mm/slub: Make object_err() static
There are no callers outside of mm/slub.c anymore.

Move freelist_corrupted() that calls object_err() to avoid a need for
forward declaration.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
2022-01-06 12:25:40 +01:00
Vlastimil Babka
c798154311 mm/slab: Dissolve slab_map_pages() in its caller
The function no longer does what its name and comment suggests, and just
sets two struct page fields, which can be done directly in its sole
caller.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
2022-01-06 12:25:25 +01:00
Matthew Wilcox (Oracle)
efe99bba28 truncate: Add truncate_cleanup_folio()
Convert both callers of truncate_cleanup_page() to use
truncate_cleanup_folio() instead.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:34 -05:00
Matthew Wilcox (Oracle)
82c50f8b44 filemap: Add filemap_release_folio()
Reimplement try_to_release_page() as a wrapper around
filemap_release_folio().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:34 -05:00
Matthew Wilcox (Oracle)
960ea971fa filemap: Use a folio in filemap_page_mkwrite
This fixes a bug for tail pages.  They always have a NULL mapping, so
the check would fail and we would never mark the folio as dirty.
Ends up growing the kernel by 19 bytes although there will be fewer
calls to compound_head() dynamically.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:34 -05:00
Matthew Wilcox (Oracle)
820b05e92b filemap: Use a folio in filemap_map_pages
Saves 61 bytes due to fewer calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:34 -05:00
Matthew Wilcox (Oracle)
9184a30776 filemap: Use folios in next_uptodate_page
This saves 105 bytes of text.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:34 -05:00
Matthew Wilcox (Oracle)
1afd7ae51f filemap: Convert page_cache_delete_batch to folios
Saves one call to compound_head() and reduces text size by 15 bytes.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:34 -05:00
Matthew Wilcox (Oracle)
65bca53b5f filemap: Convert filemap_get_pages to use folios
This saves a few calls to compound_head(), including one in
filemap_update_page().  Shrinks the kernel by 78 bytes.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:34 -05:00
Matthew Wilcox (Oracle)
81f4c03b7d filemap: Drop the refcount while waiting for page lock
Commit bd8a1f3655 ("mm/filemap: support readpage splitting a page")
changed the read_iter path to drop the refcount while waiting for the
page lock.  However, it missed the same pattern in read_mapping_page()
and friends.  Use the same pattern in do_read_cache_folio() that is
used in filemap_update_page().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:34 -05:00
Matthew Wilcox (Oracle)
539a3322f2 filemap: Add read_cache_folio and read_mapping_folio
Reimplement read_cache_page() as a wrapper around read_cache_folio().
Saves over 400 bytes of text from do_read_cache_folio() which more
than makes up for the extra 100 bytes of text added to the various
wrapper functions.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:34 -05:00
Matthew Wilcox (Oracle)
e292e6d644 filemap: Convert filemap_fault to folio
Instead of converting back-and-forth between the actual page and
the head page, just convert once at the end of the function where we
set the vmf->page.  Saves 241 bytes of text, or 15% of the size of
filemap_fault().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:34 -05:00
Matthew Wilcox (Oracle)
79598cedad filemap: Convert do_async_mmap_readahead to take a folio
Call page_cache_async_ra() directly instead of indirecting through
page_cache_async_readahead().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:34 -05:00
Matthew Wilcox (Oracle)
0387df1d1f readahead: Convert page_cache_ra_unbounded to folios
This saves 99 bytes of kernel text.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:34 -05:00
Matthew Wilcox (Oracle)
7836d99900 readahead: Convert page_cache_async_ra() to take a folio
Using the folio here avoids checking whether it's a tail page.
This patch mostly just enables some of the following patches.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:34 -05:00
Matthew Wilcox (Oracle)
2fa4eeb800 filemap: Convert filemap_range_uptodate to folios
The only caller was already passing a head page, so this simply avoids
a call to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:34 -05:00
Matthew Wilcox (Oracle)
a5d4ad0985 filemap: Convert filemap_create_page to folio
This is all internal to filemap and saves 100 bytes of text.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:33 -05:00
Matthew Wilcox (Oracle)
9d427b4eb4 filemap: Convert filemap_read_page to take a folio
One of the callers already had a folio; the other two grow by a few
bytes, but filemap_read_page() shrinks by 50 bytes for a net reduction
of 27 bytes.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:33 -05:00
Matthew Wilcox (Oracle)
e1c37722b0 filemap: Convert find_get_pages_contig to folios
None of the callers of find_get_pages_contig() want tail pages.  They all
use order-0 pages today, but if they were converted, they'd want folios.
So just remove the call to find_subpage() instead of replacing it with
folio_page().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:33 -05:00
Matthew Wilcox (Oracle)
bdb7293297 filemap: Convert filemap_get_read_batch to use folios
The page cache only stores folios, never tail pages.  Saves 29 bytes
due to removing calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:33 -05:00
Matthew Wilcox (Oracle)
f5e6429a51 filemap: Convert find_get_entry to return a folio
Convert callers to cope.  Saves 580 bytes of kernel text; all five
callers are reduced in size.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:33 -05:00
Matthew Wilcox (Oracle)
452e9e6992 filemap: Add filemap_remove_folio and __filemap_remove_folio
Reimplement __delete_from_page_cache() as a wrapper around
__filemap_remove_folio() and delete_from_page_cache() as a wrapper
around filemap_remove_folio().  Remove the EXPORT_SYMBOL as
delete_from_page_cache() was not used by any in-tree modules.
Convert page_cache_free_page() into filemap_free_folio().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:33 -05:00
Matthew Wilcox (Oracle)
a0580c6f9b filemap: Convert tracing of page cache operations to folio
Pass the folio instead of a page.  The page was already implicitly a
folio as it accessed page->mapping directly.  Add the order of the folio
to the tracepoint, as this is important information.  Also drop printing
the address of the struct page as the pfn provides better information
than the struct page address.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:33 -05:00
Matthew Wilcox (Oracle)
621db4880d filemap: Add filemap_unaccount_folio()
Replace unaccount_page_cache_page() with filemap_unaccount_folio().
The bug handling path could be a bit more robust (eg taking into account
the mapcounts of tail pages), but it's really never supposed to happen.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:33 -05:00
Matthew Wilcox (Oracle)
a548b61583 filemap: Convert page_cache_delete to take a folio
It was already assuming a head page, so this is a straightforward
conversion.  Convert the one caller to call page_folio(), even though
it must currently be passing in a head page.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:33 -05:00
Matthew Wilcox (Oracle)
9f2b04a25a filemap: Add folio_put_wait_locked()
Convert all three callers of put_and_wait_on_page_locked() to
folio_put_wait_locked().  This shrinks the kernel overall by 19 bytes.
filemap_update_page() shrinks by 19 bytes while __migration_entry_wait()
is unchanged.  folio_put_wait_locked() is 14 bytes smaller than
put_and_wait_on_page_locked(), but pmd_migration_entry_wait() grows by
14 bytes.  It removes the assumption from pmd_migration_entry_wait()
that pages cannot be larger than a PMD (which is true today, but
may be interesting to explore in the future).

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-04 13:15:33 -05:00
Matthew Wilcox (Oracle)
a229a4f00d mm/writeback: Improve __folio_mark_dirty() comment
Add some notes about how this function needs to be called.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-02 20:28:57 -05:00
Matthew Wilcox (Oracle)
9144785b02 filemap: Remove PageHWPoison check from next_uptodate_page()
Pages are individually marked as suffering from hardware poisoning.
Checking that the head page is not hardware poisoned doesn't make
sense; we might be after a subpage.  We check each page individually
before we use it, so this was an optimisation gone wrong.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2022-01-02 20:28:35 -05:00
Mel Gorman
8008293888 mm: vmscan: reduce throttling due to a failure to make progress -fix
Hugh Dickins reported the following

	My tmpfs swapping load (tweaked to use huge pages more heavily
	than in real life) is far from being a realistic load: but it was
	notably slowed down by your throttling mods in 5.16-rc, and this
	patch makes it well again - thanks.

	But: it very quickly hit NULL pointer until I changed that last
	line to

        if (first_pgdat)
                consider_reclaim_throttle(first_pgdat, sc);

The likely issue is that huge pages are a major component of the test
workload.  When this is the case, first_pgdat may never get set if
compaction is ready to continue due to this check

        if (IS_ENABLED(CONFIG_COMPACTION) &&
            sc->order > PAGE_ALLOC_COSTLY_ORDER &&
            compaction_ready(zone, sc)) {
                sc->compaction_ready = true;
                continue;
        }

If this was true for every zone in the zonelist, first_pgdat would never
get set resulting in a NULL pointer exception.

Link: https://lkml.kernel.org/r/20211209095453.GM3366@techsingularity.net
Fixes: 1b4e3f26f9 ("mm: vmscan: Reduce throttling due to a failure to make progress")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reported-by: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Rik van Riel <riel@surriel.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-31 13:12:55 -08:00
Mel Gorman
1b4e3f26f9 mm: vmscan: Reduce throttling due to a failure to make progress
Mike Galbraith, Alexey Avramov and Darrick Wong all reported similar
problems due to reclaim throttling for excessive lengths of time.  In
Alexey's case, a memory hog that should go OOM quickly stalls for
several minutes before stalling.  In Mike and Darrick's cases, a small
memcg environment stalled excessively even though the system had enough
memory overall.

Commit 69392a403f ("mm/vmscan: throttle reclaim when no progress is
being made") introduced the problem although commit a19594ca4a
("mm/vmscan: increase the timeout if page reclaim is not making
progress") made it worse.  Systems at or near an OOM state that cannot
be recovered must reach OOM quickly and memcg should kill tasks if a
memcg is near OOM.

To address this, only stall for the first zone in the zonelist, reduce
the timeout to 1 tick for VMSCAN_THROTTLE_NOPROGRESS and only stall if
the scan control nr_reclaimed is 0, kswapd is still active and there
were excessive pages pending for writeback.  If kswapd has stopped
reclaiming due to excessive failures, do not stall at all so that OOM
triggers relatively quickly.  Similarly, if an LRU is simply congested,
only lightly throttle similar to NOPROGRESS.

Alexey's original case was the most straight forward

	for i in {1..3}; do tail /dev/zero; done

On vanilla 5.16-rc1, this test stalled heavily, after the patch the test
completes in a few seconds similar to 5.15.

Alexey's second test case added watching a youtube video while tail runs
10 times.  On 5.15, playback only jitters slightly, 5.16-rc1 stalls a
lot with lots of frames missing and numerous audio glitches.  With this
patch applies, the video plays similarly to 5.15.

[lkp@intel.com: Fix W=1 build warning]

Link: https://lore.kernel.org/r/99e779783d6c7fce96448a3402061b9dc1b3b602.camel@gmx.de
Link: https://lore.kernel.org/r/20211124011954.7cab9bb4@mail.inbox.lv
Link: https://lore.kernel.org/r/20211022144651.19914-1-mgorman@techsingularity.net
Link: https://lore.kernel.org/r/20211202150614.22440-1-mgorman@techsingularity.net
Link: https://linux-regtracking.leemhuis.info/regzbot/regression/20211124011954.7cab9bb4@mail.inbox.lv/
Reported-and-tested-by: Alexey Avramov <hakavlad@inbox.lv>
Reported-and-tested-by: Mike Galbraith <efault@gmx.de>
Reported-and-tested-by: Darrick J. Wong <djwong@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Acked-by: Hugh Dickins <hughd@google.com>
Tracked-by: Thorsten Leemhuis <regressions@leemhuis.info>
Fixes: 69392a403f ("mm/vmscan: throttle reclaim when no progress is being made")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-31 11:17:07 -08:00
SeongJae Park
ebb3f994dd mm/damon/dbgfs: fix 'struct pid' leaks in 'dbgfs_target_ids_write()'
DAMON debugfs interface increases the reference counts of 'struct pid's
for targets from the 'target_ids' file write callback
('dbgfs_target_ids_write()'), but decreases the counts only in DAMON
monitoring termination callback ('dbgfs_before_terminate()').

Therefore, when 'target_ids' file is repeatedly written without DAMON
monitoring start/termination, the reference count is not decreased and
therefore memory for the 'struct pid' cannot be freed.  This commit
fixes this issue by decreasing the reference counts when 'target_ids' is
written.

Link: https://lkml.kernel.org/r/20211229124029.23348-1-sj@kernel.org
Fixes: 4bc05954d0 ("mm/damon: implement a debugfs-based user space interface")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org>	[5.15+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-31 09:20:12 -08:00
Liu Shixin
2a57d83c78 mm/hwpoison: clear MF_COUNT_INCREASED before retrying get_any_page()
Hulk Robot reported a panic in put_page_testzero() when testing
madvise() with MADV_SOFT_OFFLINE.  The BUG() is triggered when retrying
get_any_page().  This is because we keep MF_COUNT_INCREASED flag in
second try but the refcnt is not increased.

    page dumped because: VM_BUG_ON_PAGE(page_ref_count(page) == 0)
    ------------[ cut here ]------------
    kernel BUG at include/linux/mm.h:737!
    invalid opcode: 0000 [#1] PREEMPT SMP
    CPU: 5 PID: 2135 Comm: sshd Tainted: G    B             5.16.0-rc6-dirty #373
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
    RIP: release_pages+0x53f/0x840
    Call Trace:
      free_pages_and_swap_cache+0x64/0x80
      tlb_flush_mmu+0x6f/0x220
      unmap_page_range+0xe6c/0x12c0
      unmap_single_vma+0x90/0x170
      unmap_vmas+0xc4/0x180
      exit_mmap+0xde/0x3a0
      mmput+0xa3/0x250
      do_exit+0x564/0x1470
      do_group_exit+0x3b/0x100
      __do_sys_exit_group+0x13/0x20
      __x64_sys_exit_group+0x16/0x20
      do_syscall_64+0x34/0x80
      entry_SYSCALL_64_after_hwframe+0x44/0xae
    Modules linked in:
    ---[ end trace e99579b570fe0649 ]---
    RIP: 0010:release_pages+0x53f/0x840

Link: https://lkml.kernel.org/r/20211221074908.3910286-1-liushixin2@huawei.com
Fixes: b94e02822d ("mm,hwpoison: try to narrow window race for free pages")
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-25 12:20:56 -08:00
SeongJae Park
3479641796 mm/damon/dbgfs: protect targets destructions with kdamond_lock
DAMON debugfs interface iterates current monitoring targets in
'dbgfs_target_ids_read()' while holding the corresponding
'kdamond_lock'.  However, it also destructs the monitoring targets in
'dbgfs_before_terminate()' without holding the lock.  This can result in
a use_after_free bug.  This commit avoids the race by protecting the
destruction with the corresponding 'kdamond_lock'.

Link: https://lkml.kernel.org/r/20211221094447.2241-1-sj@kernel.org
Reported-by: Sangwoo Bae <sangwoob@amazon.com>
Fixes: 4bc05954d0 ("mm/damon: implement a debugfs-based user space interface")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org>	[5.15.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-25 12:20:56 -08:00
Naoya Horiguchi
e37e7b0b3b mm, hwpoison: fix condition in free hugetlb page path
When a memory error hits a tail page of a free hugepage,
__page_handle_poison() is expected to be called to isolate the error in
4kB unit, but it's not called due to the outdated if-condition in
memory_failure_hugetlb().  This loses the chance to isolate the error in
the finer unit, so it's not optimal.  Drop the condition.

This "(p != head && TestSetPageHWPoison(head)" condition is based on the
old semantics of PageHWPoison on hugepage (where PG_hwpoison flag was
set on the subpage), so it's not necessray any more.  By getting to set
PG_hwpoison on head page for hugepages, concurrent error events on
different subpages in a single hugepage can be prevented by
TestSetPageHWPoison(head) at the beginning of memory_failure_hugetlb().
So dropping the condition should not reopen the race window originally
mentioned in commit b985194c8c ("hwpoison, hugetlb:
lock_page/unlock_page does not match for handling a free hugepage")

[naoya.horiguchi@linux.dev: fix "HardwareCorrupted" counter]
  Link: https://lkml.kernel.org/r/20211220084851.GA1460264@u2004

Link: https://lkml.kernel.org/r/20211210110208.879740-1-naoya.horiguchi@linux.dev
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reported-by: Fei Luo <luofei@unicloud.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org>	[5.14+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-25 12:20:55 -08:00
Andrey Ryabinin
3386353406 mm: mempolicy: fix THP allocations escaping mempolicy restrictions
alloc_pages_vma() may try to allocate THP page on the local NUMA node
first:

	page = __alloc_pages_node(hpage_node,
		gfp | __GFP_THISNODE | __GFP_NORETRY, order);

And if the allocation fails it retries allowing remote memory:

	if (!page && (gfp & __GFP_DIRECT_RECLAIM))
    		page = __alloc_pages_node(hpage_node,
					gfp, order);

However, this retry allocation completely ignores memory policy nodemask
allowing allocation to escape restrictions.

The first appearance of this bug seems to be the commit ac5b2c1891
("mm: thp: relax __GFP_THISNODE for MADV_HUGEPAGE mappings").

The bug disappeared later in the commit 89c83fb539 ("mm, thp:
consolidate THP gfp handling into alloc_hugepage_direct_gfpmask") and
reappeared again in slightly different form in the commit 76e654cc91
("mm, page_alloc: allow hugepage fallback to remote nodes when
madvised")

Fix this by passing correct nodemask to the __alloc_pages() call.

The demonstration/reproducer of the problem:

    $ mount -oremount,size=4G,huge=always /dev/shm/
    $ echo always > /sys/kernel/mm/transparent_hugepage/defrag
    $ cat mbind_thp.c
    #include <unistd.h>
    #include <sys/mman.h>
    #include <sys/stat.h>
    #include <fcntl.h>
    #include <assert.h>
    #include <stdlib.h>
    #include <stdio.h>
    #include <numaif.h>

    #define SIZE 2ULL << 30
    int main(int argc, char **argv)
    {
        int fd;
        unsigned long long i;
        char *addr;
        pid_t pid;
        char buf[100];
        unsigned long nodemask = 1;

        fd = open("/dev/shm/test", O_RDWR|O_CREAT);
        assert(fd > 0);
        assert(ftruncate(fd, SIZE) == 0);

        addr = mmap(NULL, SIZE, PROT_READ|PROT_WRITE,
                           MAP_SHARED, fd, 0);

        assert(mbind(addr, SIZE, MPOL_BIND, &nodemask, 2, MPOL_MF_STRICT|MPOL_MF_MOVE)==0);
        for (i = 0; i < SIZE; i+=4096) {
          addr[i] = 1;
        }
        pid = getpid();
        snprintf(buf, sizeof(buf), "grep shm /proc/%d/numa_maps", pid);
        system(buf);
        sleep(10000);

        return 0;
    }
    $ gcc mbind_thp.c -o mbind_thp -lnuma
    $ numactl -H
    available: 2 nodes (0-1)
    node 0 cpus: 0 2
    node 0 size: 1918 MB
    node 0 free: 1595 MB
    node 1 cpus: 1 3
    node 1 size: 2014 MB
    node 1 free: 1731 MB
    node distances:
    node   0   1
      0:  10  20
      1:  20  10
    $ rm -f /dev/shm/test; taskset -c 0 ./mbind_thp
    7fd970a00000 bind:0 file=/dev/shm/test dirty=524288 active=0 N0=396800 N1=127488 kernelpagesize_kB=4

Link: https://lkml.kernel.org/r/20211208165343.22349-1-arbn@yandex-team.com
Fixes: ac5b2c1891 ("mm: thp: relax __GFP_THISNODE for MADV_HUGEPAGE mappings")
Signed-off-by: Andrey Ryabinin <arbn@yandex-team.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-25 12:20:55 -08:00
Baokun Li
0129ab1f26 kfence: fix memory leak when cat kfence objects
Hulk robot reported a kmemleak problem:

    unreferenced object 0xffff93d1d8cc02e8 (size 248):
      comm "cat", pid 23327, jiffies 4624670141 (age 495992.217s)
      hex dump (first 32 bytes):
        00 40 85 19 d4 93 ff ff 00 10 00 00 00 00 00 00  .@..............
        00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
      backtrace:
         seq_open+0x2a/0x80
         full_proxy_open+0x167/0x1e0
         do_dentry_open+0x1e1/0x3a0
         path_openat+0x961/0xa20
         do_filp_open+0xae/0x120
         do_sys_openat2+0x216/0x2f0
         do_sys_open+0x57/0x80
         do_syscall_64+0x33/0x40
         entry_SYSCALL_64_after_hwframe+0x44/0xa9
    unreferenced object 0xffff93d419854000 (size 4096):
      comm "cat", pid 23327, jiffies 4624670141 (age 495992.217s)
      hex dump (first 32 bytes):
        6b 66 65 6e 63 65 2d 23 32 35 30 3a 20 30 78 30  kfence-#250: 0x0
        30 30 30 30 30 30 30 37 35 34 62 64 61 31 32 2d  0000000754bda12-
      backtrace:
         seq_read_iter+0x313/0x440
         seq_read+0x14b/0x1a0
         full_proxy_read+0x56/0x80
         vfs_read+0xa5/0x1b0
         ksys_read+0xa0/0xf0
         do_syscall_64+0x33/0x40
         entry_SYSCALL_64_after_hwframe+0x44/0xa9

I find that we can easily reproduce this problem with the following
commands:

	cat /sys/kernel/debug/kfence/objects
	echo scan > /sys/kernel/debug/kmemleak
	cat /sys/kernel/debug/kmemleak

The leaked memory is allocated in the stack below:

    do_syscall_64
      do_sys_open
        do_dentry_open
          full_proxy_open
            seq_open            ---> alloc seq_file
      vfs_read
        full_proxy_read
          seq_read
            seq_read_iter
              traverse          ---> alloc seq_buf

And it should have been released in the following process:

    do_syscall_64
      syscall_exit_to_user_mode
        exit_to_user_mode_prepare
          task_work_run
            ____fput
              __fput
                full_proxy_release  ---> free here

However, the release function corresponding to file_operations is not
implemented in kfence.  As a result, a memory leak occurs.  Therefore,
the solution to this problem is to implement the corresponding release
function.

Link: https://lkml.kernel.org/r/20211206133628.2822545-1-libaokun1@huawei.com
Fixes: 0ce20dd840 ("mm: add Kernel Electric-Fence infrastructure")
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Acked-by: Marco Elver <elver@google.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-25 12:20:55 -08:00
Linus Torvalds
8f97a35a53 Merge branch 'for-5.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu
Pull percpu fixes from Dennis Zhou:
 "This contains a fix for SMP && !MMU archs for percpu which has been
  tested by arm and sh. It seems in the past they have gotten away with
  it due to mapping of vm functions to km functions, but this fell apart
  a few releases ago and was just reported recently.

  The other is just a minor dependency clean up.

  I think queued up right now by Andrew is a fix in percpu that papers
  of what seems to be a bug in hotplug for a special situation with
  memoryless nodes. Michal Hocko is digging into it further"

* 'for-5.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu:
  percpu_ref: Replace kernel.h with the necessary inclusions
  percpu: km: ensure it is used with NOMMU (either UP or SMP)
2021-12-11 16:14:17 -08:00
Manjong Lee
3c376dfafb mm: bdi: initialize bdi_min_ratio when bdi is unregistered
Initialize min_ratio if it is set during bdi unregistration.  This can
prevent problems that may occur a when bdi is removed without resetting
min_ratio.

For example.
1) insert external sdcard
2) set external sdcard's min_ratio 70
3) remove external sdcard without setting min_ratio 0
4) insert external sdcard
5) set external sdcard's min_ratio 70 << error occur(can't set)

Because when an sdcard is removed, the present bdi_min_ratio value will
remain.  Currently, the only way to reset bdi_min_ratio is to reboot.

[akpm@linux-foundation.org: tweak comment and coding style]

Link: https://lkml.kernel.org/r/20211021161942.5983-1-mj0123.lee@samsung.com
Signed-off-by: Manjong Lee <mj0123.lee@samsung.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Changheun Lee <nanich.lee@samsung.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <seunghwan.hyun@samsung.com>
Cc: <sookwan7.kim@samsung.com>
Cc: <yt0928.kim@samsung.com>
Cc: <junho89.kim@samsung.com>
Cc: <jisoo2146.oh@samsung.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-10 17:10:56 -08:00
Zhenguo Yao
4178158ef8 hugetlbfs: fix issue of preallocation of gigantic pages can't work
Preallocation of gigantic pages can't work bacause of commit
b5389086ad ("hugetlbfs: extend the definition of hugepages parameter
to support node allocation").  When nid is NUMA_NO_NODE(-1),
alloc_bootmem_huge_page will always return without doing allocation.
Fix this by adding more check.

Link: https://lkml.kernel.org/r/20211129133803.15653-1-yaozhenguo1@gmail.com
Fixes: b5389086ad ("hugetlbfs: extend the definition of hugepages parameter to support node allocation")
Signed-off-by: Zhenguo Yao <yaozhenguo1@gmail.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Tested-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-10 17:10:56 -08:00
Waiman Long
a7ebf564de mm/memcg: relocate mod_objcg_mlstate(), get_obj_stock() and put_obj_stock()
All the calls to mod_objcg_mlstate(), get_obj_stock() and
put_obj_stock() are done by functions defined within the same "#ifdef
CONFIG_MEMCG_KMEM" compilation block.  When CONFIG_MEMCG_KMEM isn't
defined, the following compilation warnings will be issued [1] and [2].

  mm/memcontrol.c:785:20: warning: unused function 'mod_objcg_mlstate'
  mm/memcontrol.c:2113:33: warning: unused function 'get_obj_stock'

Fix these warning by moving those functions to under the same
CONFIG_MEMCG_KMEM compilation block.  There is no functional change.

[1] https://lore.kernel.org/lkml/202111272014.WOYNLUV6-lkp@intel.com/
[2] https://lore.kernel.org/lkml/202111280551.LXsWYt1T-lkp@intel.com/

Link: https://lkml.kernel.org/r/20211129161140.306488-1-longman@redhat.com
Fixes: 559271146e ("mm/memcg: optimize user context object stock access")
Fixes: 68ac5b3c8d ("mm/memcg: cache vmstat data in percpu memcg_stock_pcp")
Signed-off-by: Waiman Long <longman@redhat.com>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-10 17:10:56 -08:00
Gerald Schaefer
005a79e5c2 mm/slub: fix endianness bug for alloc/free_traces attributes
On big-endian s390, the alloc/free_traces attributes produce endless
output, because of always 0 idx in slab_debugfs_show().

idx is de-referenced from *v, which points to a loff_t value, with

    unsigned int idx = *(unsigned int *)v;

This will only give the upper 32 bits on big-endian, which remain 0.

Instead of only fixing this de-reference, during discussion it seemed
more appropriate to change the seq_ops so that they use an explicit
iterator in private loc_track struct.

This patch adds idx to loc_track, which will also fix the endianness
bug.

Link: https://lore.kernel.org/r/20211117193932.4049412-1-gerald.schaefer@linux.ibm.com
Link: https://lkml.kernel.org/r/20211126171848.17534-1-gerald.schaefer@linux.ibm.com
Fixes: 64dd68497b ("mm: slub: move sysfs slab alloc/free interfaces to debugfs")
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Reported-by: Steffen Maier <maier@linux.ibm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Faiyaz Mohammed <faiyazm@codeaurora.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-10 17:10:56 -08:00
SeongJae Park
9f86d62429 mm/damon/vaddr-test: remove unnecessary variables
A couple of test functions in DAMON virtual address space monitoring
primitives implementation has unnecessary damon_ctx variables.  This
commit removes those.

Link: https://lkml.kernel.org/r/20211201150440.1088-7-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-10 17:10:56 -08:00
SeongJae Park
044cd9750f mm/damon/vaddr-test: split a test function having >1024 bytes frame size
On some configuration[1], 'damon_test_split_evenly()' kunit test
function has >1024 bytes frame size, so below build warning is
triggered:

      CC      mm/damon/vaddr.o
    In file included from mm/damon/vaddr.c:672:
    mm/damon/vaddr-test.h: In function 'damon_test_split_evenly':
    mm/damon/vaddr-test.h:309:1: warning: the frame size of 1064 bytes is larger than 1024 bytes [-Wframe-larger-than=]
      309 | }
          | ^

This commit fixes the warning by separating the common logic in the
function.

[1] https://lore.kernel.org/linux-mm/202111182146.OV3C4uGr-lkp@intel.com/

Link: https://lkml.kernel.org/r/20211201150440.1088-6-sj@kernel.org
Fixes: 17ccae8bb5 ("mm/damon: add kunit tests")
Signed-off-by: SeongJae Park <sj@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-10 17:10:56 -08:00
SeongJae Park
09e12289cc mm/damon/vaddr: remove an unnecessary warning message
The DAMON virtual address space monitoring primitive prints a warning
message for wrong DAMOS action.  However, it is not essential as the
code returns appropriate failure in the case.  This commit removes the
message to make the log clean.

Link: https://lkml.kernel.org/r/20211201150440.1088-5-sj@kernel.org
Fixes: 6dea8add4d ("mm/damon/vaddr: support DAMON-based Operation Schemes")
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-10 17:10:56 -08:00
SeongJae Park
1afaf5cb68 mm/damon/core: remove unnecessary error messages
DAMON core prints error messages when damon_target object creation is
failed or wrong monitoring attributes are given.  Because appropriate
error code is returned for each case, the messages are not essential.
Also, because the code path can be triggered with user-specified input,
this could result in kernel log mistakenly being messy.  To avoid the
case, this commit removes the messages.

Link: https://lkml.kernel.org/r/20211201150440.1088-4-sj@kernel.org
Fixes: 4bc05954d0 ("mm/damon: implement a debugfs-based user space interface")
Fixes: b9a6ac4e4e ("mm/damon: adaptively adjust regions")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-10 17:10:55 -08:00
SeongJae Park
0bceffa236 mm/damon/dbgfs: remove an unnecessary error message
When wrong scheme action is requested via the debugfs interface, DAMON
prints an error message.  Because the function returns error code, this
is not really needed.  Because the code path is triggered by the user
specified input, this can result in kernel log mistakenly being messy.
To avoid the case, this commit removes the message.

Link: https://lkml.kernel.org/r/20211201150440.1088-3-sj@kernel.org
Fixes: af122dd8f3 ("mm/damon/dbgfs: support DAMON-based Operation Schemes")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-10 17:10:55 -08:00
SeongJae Park
4de46a30b9 mm/damon/core: use better timer mechanisms selection threshold
Patch series "mm/damon: Trivial fixups and improvements".

This patchset contains trivial fixups and improvements for DAMON and its
kunit/kselftest tests.

This patch (of 11):

DAMON is using hrtimer if requested sleep time is <=100ms, while the
suggested threshold[1] is <=20ms.  This commit applies the threshold.

[1] Documentation/timers/timers-howto.rst

Link: https://lkml.kernel.org/r/20211201150440.1088-2-sj@kernel.org
Fixes: ee801b7dd7 ("mm/damon/schemes: activate schemes based on a watermarks mechanism")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-10 17:10:55 -08:00
SeongJae Park
70e9274805 mm/damon/core: fix fake load reports due to uninterruptible sleeps
Because DAMON sleeps in uninterruptible mode, /proc/loadavg reports fake
load while DAMON is turned on, though it is doing nothing.  This can
confuse users[1].  To avoid the case, this commit makes DAMON sleeps in
idle mode.

[1] https://lore.kernel.org/all/11868371.O9o76ZdvQC@natalenko.name/

Link: https://lkml.kernel.org/r/20211126145015.15862-3-sj@kernel.org
Fixes: 2224d84854 ("mm: introduce Data Access MONitor (DAMON)")
Reported-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: SeongJae Park <sj@kernel.org>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-10 17:10:55 -08:00
Matthew Wilcox (Oracle)
0c941cf30b filemap: remove PageHWPoison check from next_uptodate_page()
Pages are individually marked as suffering from hardware poisoning.
Checking that the head page is not hardware poisoned doesn't make
sense; we might be after a subpage.  We check each page individually
before we use it, so this was an optimisation gone wrong.  It will
cause us to fall back to the slow path when there was no need to do
that

Link: https://lkml.kernel.org/r/20211120174429.2596303-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-10 17:10:55 -08:00
Marco Elver
d37d1fa015 mm, kcsan: Enable barrier instrumentation
Some memory management calls imply memory barriers that are required to
avoid false positives. For example, without the correct instrumentation,
we could observe data races of the following variant:

                   T0           |           T1
        ------------------------+------------------------
                                |
         *a = 42;    ---+       |
         kfree(a);      |       |
                        |       | b = kmalloc(..); // b == a
          <reordered> <-+       | *b = 42;         // not a data race!
                                |

Therefore, instrument memory barriers in all allocator code currently
not being instrumented in a default build.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 16:42:28 -08:00
Jakub Kicinski
6efcdadc15 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
bpf 2021-12-08

We've added 12 non-merge commits during the last 22 day(s) which contain
a total of 29 files changed, 659 insertions(+), 80 deletions(-).

The main changes are:

1) Fix an off-by-two error in packet range markings and also add a batch of
   new tests for coverage of these corner cases, from Maxim Mikityanskiy.

2) Fix a compilation issue on MIPS JIT for R10000 CPUs, from Johan Almbladh.

3) Fix two functional regressions and a build warning related to BTF kfunc
   for modules, from Kumar Kartikeya Dwivedi.

4) Fix outdated code and docs regarding BPF's migrate_disable() use on non-
   PREEMPT_RT kernels, from Sebastian Andrzej Siewior.

5) Add missing includes in order to be able to detangle cgroup vs bpf header
   dependencies, from Jakub Kicinski.

6) Fix regression in BPF sockmap tests caused by missing detachment of progs
   from sockets when they are removed from the map, from John Fastabend.

7) Fix a missing "no previous prototype" warning in x86 JIT caused by BPF
   dispatcher, from Björn Töpel.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf: Add selftests to cover packet access corner cases
  bpf: Fix the off-by-two error in range markings
  treewide: Add missing includes masked by cgroup -> bpf dependency
  tools/resolve_btfids: Skip unresolved symbol warning for empty BTF sets
  bpf: Fix bpf_check_mod_kfunc_call for built-in modules
  bpf: Make CONFIG_DEBUG_INFO_BTF depend upon CONFIG_BPF_SYSCALL
  mips, bpf: Fix reference to non-existing Kconfig symbol
  bpf: Make sure bpf_disable_instrumentation() is safe vs preemption.
  Documentation/locking/locktypes: Update migrate_disable() bits.
  bpf, sockmap: Re-evaluate proto ops when psock is removed from sockmap
  bpf, sockmap: Attach map progs to psock early for feature probes
  bpf, x86: Fix "no previous prototype" warning
====================

Link: https://lore.kernel.org/r/20211208155125.11826-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-08 16:06:44 -08:00
Vladimir Murzin
3583521aab percpu: km: ensure it is used with NOMMU (either UP or SMP)
Currently, NOMMU pull km allocator via !SMP dependency because most of
them are UP, yet for SMP+NOMMU vm allocator gets pulled which:

* may lead to broken build [1]
* ...or not working runtime due to [2]

It looks like SMP+NOMMU case was overlooked in bbddff0545 ("percpu:
use percpu allocator on UP too") so restore that.

[1]
For ARM SMP+NOMMU (R-class cores)

arm-none-linux-gnueabihf-ld: mm/percpu.o: in function `pcpu_post_unmap_tlb_flush':
mm/percpu-vm.c:188: undefined reference to `flush_tlb_kernel_range'

[2]
static inline
int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
                pgprot_t prot, struct page **pages, unsigned int page_shift)
{
       return -EINVAL;
}

Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Tested-by: Rob Landley <rob@landley.net>
Tested-by: Rich Felker <dalias@libc.org>
[Dennis: use depends instead of default for condition]
Signed-off-by: Dennis Zhou <dennis@kernel.org>
2021-12-06 12:45:09 -05:00
Christoph Hellwig
b80892ca02 memremap: remove support for external pgmap refcounts
No driver is left using the external pgmap refcount, so remove the
code to support it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20211028151017.50234-1-hch@lst.de
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-12-04 12:46:09 -08:00
Jens Axboe
4bdcd1dd4d mm: move filemap_range_needs_writeback() into header
No functional changes in this patch, just in preparation for efficiently
calling this light function from the block O_DIRECT handling.

Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-03 14:51:26 -07:00
Jakub Kicinski
8581fd402a treewide: Add missing includes masked by cgroup -> bpf dependency
cgroup.h (therefore swap.h, therefore half of the universe)
includes bpf.h which in turn includes module.h and slab.h.
Since we're about to get rid of that dependency we need
to clean things up.

v2: drop the cpu.h include from cacheinfo.h, it's not necessary
and it makes riscv sensitive to ordering of include files.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Krzysztof Wilczyński <kw@linux.com>
Acked-by: Peter Chen <peter.chen@kernel.org>
Acked-by: SeongJae Park <sj@kernel.org>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/all/20211120035253.72074-1-kuba@kernel.org/  # v1
Link: https://lore.kernel.org/all/20211120165528.197359-1-kuba@kernel.org/ # cacheinfo discussion
Link: https://lore.kernel.org/bpf/20211202203400.1208663-1-kuba@kernel.org
2021-12-03 10:58:13 -08:00
Linus Torvalds
79941493ff Fixes for 5.16 folios:
- Fix compilation warnings on csky and sparc
  - Rename multipage folios to large folios
  - Rename AS_THP_SUPPORT and FS_THP_SUPPORT
  - Add functions to zero portions of a folio
 -----BEGIN PGP SIGNATURE-----
 
 iQEzBAABCgAdFiEEejHryeLBw/spnjHrDpNsjXcpgj4FAmGem6wACgkQDpNsjXcp
 gj7uvwgAjNqDWOVgwYU98daN6nKQQf5Vv35f0bzeKcKcHIOEWZ2+MUeXkI55h8TD
 ss5L3O86sPtQmpKUQJJChZC4AhpIPRyjPA0JW6vYqXQd912M331WpGgFFyX5eI+3
 OxfKLRULmopeWP1RjWmkWqlhYQHL5OLgAMC4VaBSfDHd1UMRf+F9JNm9qR7GCp9Q
 Vb0qcmBMaQYt/K5sWRQyPUACVTF+27RLKAs+Om37NGekv1UqgOPMzi9nAyi9RjCi
 rRY6oGupNgC+Y41jzlpaNoL71RPS92H769FBh/Fe4qu55VSPjfcN77qAnVhX5Ykn
 4RhzZcEUoqlx9xG9xynk0mmbx2Bf4g==
 =kvqM
 -----END PGP SIGNATURE-----

Merge tag 'folio-5.16b' of git://git.infradead.org/users/willy/pagecache

Pull folio fixes from Matthew Wilcox:
 "In the course of preparing the folio changes for iomap for next merge
  window, we discovered some problems that would be nice to address now:

   - Renaming multi-page folios to large folios.

     mapping_multi_page_folio_support() is just a little too long, so we
     settled on mapping_large_folio_support(). That meant renaming, eg
     folio_test_multi() to folio_test_large().

     Rename AS_THP_SUPPORT to match

   - I hadn't included folio wrappers for zero_user_segments(), etc.
     Also, multi-page^W^W large folio support is now independent of
     CONFIG_TRANSPARENT_HUGEPAGE, so machines with HIGHMEM always need
     to fall back to the out-of-line zero_user_segments().

     Remove FS_THP_SUPPORT to match

   - The build bots finally got round to telling me that I missed a
     couple of architectures when adding flush_dcache_folio(). Christoph
     suggested that we just add linux/cacheflush.h and not rely on
     asm-generic/cacheflush.h"

* tag 'folio-5.16b' of git://git.infradead.org/users/willy/pagecache:
  mm: Add functions to zero portions of a folio
  fs: Rename AS_THP_SUPPORT and mapping_thp_support
  fs: Remove FS_THP_SUPPORT
  mm: Remove folio_test_single
  mm: Rename folio_test_multi to folio_test_large
  Add linux/cacheflush.h
2021-11-25 10:13:56 -08:00
Nadav Amit
13e4ad2ce8 hugetlbfs: flush before unlock on move_hugetlb_page_tables()
We must flush the TLB before releasing i_mmap_rwsem to avoid the
potential reuse of an unshared PMDs page.  This is not true in the case
of move_hugetlb_page_tables().  The last reference on the page table can
therefore be dropped before the TLB flush took place.

Prevent it by reordering the operations and flushing the TLB before
releasing i_mmap_rwsem.

Fixes: 550a7d60bd ("mm, hugepages: add mremap() support for hugepage backed vma")
Signed-off-by: Nadav Amit <namit@vmware.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-22 11:36:46 -08:00
Nadav Amit
a4a118f2ee hugetlbfs: flush TLBs correctly after huge_pmd_unshare
When __unmap_hugepage_range() calls to huge_pmd_unshare() succeed, a TLB
flush is missing.  This TLB flush must be performed before releasing the
i_mmap_rwsem, in order to prevent an unshared PMDs page from being
released and reused before the TLB flush took place.

Arguably, a comprehensive solution would use mmu_gather interface to
batch the TLB flushes and the PMDs page release, however it is not an
easy solution: (1) try_to_unmap_one() and try_to_migrate_one() also call
huge_pmd_unshare() and they cannot use the mmu_gather interface; and (2)
deferring the release of the page reference for the PMDs page until
after i_mmap_rwsem is dropeed can confuse huge_pmd_unshare() into
thinking PMDs are shared when they are not.

Fix __unmap_hugepage_range() by adding the missing TLB flush, and
forcing a flush when unshare is successful.

Fixes: 24669e5847 ("hugetlb: use mmu_gather instead of a temporary linked list for accumulating pages)" # 3.6
Signed-off-by: Nadav Amit <namit@vmware.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-22 11:36:46 -08:00
Ard Biesheuvel
825c43f50e kmap_local: don't assume kmap PTEs are linear arrays in memory
The kmap_local conversion broke the ARM architecture, because the new
code assumes that all PTEs used for creating kmaps form a linear array
in memory, and uses array indexing to look up the kmap PTE belonging to
a certain kmap index.

On ARM, this cannot work, not only because the PTE pages may be
non-adjacent in memory, but also because ARM/!LPAE interleaves hardware
entries and extended entries (carrying software-only bits) in a way that
is not compatible with array indexing.

Fortunately, this only seems to affect configurations with more than 8
CPUs, due to the way the per-CPU kmap slots are organized in memory.

Work around this by permitting an architecture to set a Kconfig symbol
that signifies that the kmap PTEs do not form a lineary array in memory,
and so the only way to locate the appropriate one is to walk the page
tables.

Link: https://lore.kernel.org/linux-arm-kernel/20211026131249.3731275-1-ardb@kernel.org/
Link: https://lkml.kernel.org/r/20211116094737.7391-1-ardb@kernel.org
Fixes: 2a15ba82fa ("ARM: highmem: Switch to generic kmap atomic")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reported-by: Quanyang Wang <quanyang.wang@windriver.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-20 10:35:54 -08:00
SeongJae Park
d78f3853f8 mm/damon/dbgfs: fix missed use of damon_dbgfs_lock
DAMON debugfs is supposed to protect dbgfs_ctxs, dbgfs_nr_ctxs, and
dbgfs_dirs using damon_dbgfs_lock.  However, some of the code is
accessing the variables without the protection.  This fixes it by
protecting all such accesses.

Link: https://lkml.kernel.org/r/20211110145758.16558-3-sj@kernel.org
Fixes: 75c1c2b53c ("mm/damon/dbgfs: support multiple contexts")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-20 10:35:54 -08:00
SeongJae Park
db7a347b26 mm/damon/dbgfs: use '__GFP_NOWARN' for user-specified size buffer allocation
Patch series "DAMON fixes".

This patch (of 2):

DAMON users can trigger below warning in '__alloc_pages()' by invoking
write() to some DAMON debugfs files with arbitrarily high count
argument, because DAMON debugfs interface allocates some buffers based
on the user-specified 'count'.

        if (unlikely(order >= MAX_ORDER)) {
                WARN_ON_ONCE(!(gfp & __GFP_NOWARN));
                return NULL;
        }

Because the DAMON debugfs interface code checks failure of the
'kmalloc()', this commit simply suppresses the warnings by adding
'__GFP_NOWARN' flag.

Link: https://lkml.kernel.org/r/20211110145758.16558-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20211110145758.16558-2-sj@kernel.org
Fixes: 4bc05954d0 ("mm/damon: implement a debugfs-based user space interface")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-20 10:35:54 -08:00
Mina Almasry
cc30042df6 hugetlb, userfaultfd: fix reservation restore on userfaultfd error
Currently in the is_continue case in hugetlb_mcopy_atomic_pte(), if we
bail out using "goto out_release_unlock;" in the cases where idx >=
size, or !huge_pte_none(), the code will detect that new_pagecache_page
== false, and so call restore_reserve_on_error().  In this case I see
restore_reserve_on_error() delete the reservation, and the following
call to remove_inode_hugepages() will increment h->resv_hugepages
causing a 100% reproducible leak.

We should treat the is_continue case similar to adding a page into the
pagecache and set new_pagecache_page to true, to indicate that there is
no reservation to restore on the error path, and we need not call
restore_reserve_on_error().  Rename new_pagecache_page to
page_in_pagecache to make that clear.

Link: https://lkml.kernel.org/r/20211117193825.378528-1-almasrymina@google.com
Fixes: c7b1850dfb ("hugetlb: don't pass page cache pages to restore_reserve_on_error")
Signed-off-by: Mina Almasry <almasrymina@google.com>
Reported-by: James Houghton <jthoughton@google.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Wei Xu <weixugc@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-20 10:35:54 -08:00
Bui Quang Minh
afe041c2d0 hugetlb: fix hugetlb cgroup refcounting during mremap
When hugetlb_vm_op_open() is called during copy_vma(), we may take the
reference to resv_map->css.  Later, when clearing the reservation
pointer of old_vma after transferring it to new_vma, we forget to drop
the reference to resv_map->css.  This leads to a reference leak of css.

Fixes this by adding a check to drop reservation css reference in
clear_vma_resv_huge_pages()

Link: https://lkml.kernel.org/r/20211113154412.91134-1-minhquangbui99@gmail.com
Fixes: 550a7d60bd ("mm, hugepages: add mremap() support for hugepage backed vma")
Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-20 10:35:54 -08:00
Rustam Kovhaev
34dbc3aaf5 mm: kmemleak: slob: respect SLAB_NOLEAKTRACE flag
When kmemleak is enabled for SLOB, system does not boot and does not
print anything to the console.  At the very early stage in the boot
process we hit infinite recursion from kmemleak_init() and eventually
kernel crashes.

kmemleak_init() specifies SLAB_NOLEAKTRACE for KMEM_CACHE(), but
kmem_cache_create_usercopy() removes it because CACHE_CREATE_MASK is not
valid for SLOB.

Let's fix CACHE_CREATE_MASK and make kmemleak work with SLOB

Link: https://lkml.kernel.org/r/20211115020850.3154366-1-rkovhaev@gmail.com
Fixes: d8843922fb ("slab: Ignore internal flags in cache creation")
Signed-off-by: Rustam Kovhaev <rkovhaev@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Glauber Costa <glommer@parallels.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-20 10:35:54 -08:00
Yunfeng Ye
9a543f007b mm: emit the "free" trace report before freeing memory in kmem_cache_free()
After the memory is freed, it can be immediately allocated by other
CPUs, before the "free" trace report has been emitted.  This causes
inaccurate traces.

For example, if the following sequence of events occurs:

    CPU 0                 CPU 1

  (1) alloc xxxxxx
  (2) free  xxxxxx
                         (3) alloc xxxxxx
                         (4) free  xxxxxx

Then they will be inaccurately reported via tracing, so that they appear
to have happened in this order:

    CPU 0                 CPU 1

  (1) alloc xxxxxx
                         (2) alloc xxxxxx
  (3) free  xxxxxx
                         (4) free  xxxxxx

This makes it look like CPU 1 somehow managed to allocate memory that
CPU 0 still had allocated for itself.

In order to avoid this, emit the "free xxxxxx" tracing report just
before the actual call to free the memory, instead of just after it.

Link: https://lkml.kernel.org/r/374eb75d-7404-8721-4e1e-65b0e5b17279@huawei.com
Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-20 10:35:54 -08:00
Matthew Wilcox
3cd018b4d6 mm/swap.c:put_pages_list(): reinitialise the page list
While free_unref_page_list() puts pages onto the CPU local LRU list, it
does not remove them from the list they were passed in on.  That makes
the list_head appear to be non-empty, and would lead to various
corruption problems if we didn't have an assertion that the list was
empty.

Reinitialise the list after calling free_unref_page_list() to avoid this
problem.

Link: https://lkml.kernel.org/r/YYp40A2lNrxaZji8@casper.infradead.org
Fixes: 988c69f1bc ("mm: optimise put_pages_list()")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Steve French <stfrench@microsoft.com>
Reported-by: Namjae Jeon <linkinjeon@kernel.org>
Tested-by: Steve French <stfrench@microsoft.com>
Tested-by: Namjae Jeon <linkinjeon@kernel.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Hyeoncheol Lee <hyc.lee@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-20 10:35:54 -08:00
Matthew Wilcox (Oracle)
c035713998 mm: Add functions to zero portions of a folio
These functions are wrappers around zero_user_segments(), which means
that zero_user_segments() can now be called for compound pages even when
CONFIG_TRANSPARENT_HUGEPAGE is disabled.

Use 'xend' as the name of the parameter to indicate that this is an
excluded end, not the more usual included end.  Excluding the end makes
more sense to the callers, but can cause confusion to readers who are
more used to seeing included ends.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2021-11-18 15:05:56 -05:00
Matthew Wilcox (Oracle)
ff36da69bc fs: Remove FS_THP_SUPPORT
Instead of setting a bit in the fs_flags to set a bit in the
address_space, set the bit in the address_space directly.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2021-11-17 10:36:35 -05:00
Matthew Wilcox (Oracle)
a1efe484dd mm: Remove folio_test_single
There's no need for this predicate; callers can just use
!folio_test_large().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2021-11-17 10:36:35 -05:00
Matthew Wilcox (Oracle)
9c3252152e mm: Rename folio_test_multi to folio_test_large
This is a better name.  Also add kernel-doc.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2021-11-17 10:36:35 -05:00
Tony Luck
03b122da74 x86/sgx: Hook arch_memory_failure() into mainline code
Add a call inside memory_failure() to call the arch specific code
to check if the address is an SGX EPC page and handle it.

Note the SGX EPC pages do not have a "struct page" entry, so the hook
goes in at the same point as the device mapping hook.

Pull the call to acquire the mutex earlier so the SGX errors are also
protected.

Make set_mce_nospec() skip SGX pages when trying to adjust
the 1:1 map.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Tested-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lkml.kernel.org/r/20211026220050.697075-6-tony.luck@intel.com
2021-11-15 11:13:16 -08:00
Linus Torvalds
d0b51bfb23 Revert "mm: shmem: don't truncate page if memory failure happens"
This reverts commit b9d02f1bdd.

The error handling of that patch was fundamentally broken, and it needs
to be entirely re-done.

For example, in shmem_write_begin() it would call shmem_getpage(), then
ignore the error return from that, and look at the page pointer contents
instead.

And in shmem_read_mapping_page_gfp(), the patch tested PageHWPoison() on
a page pointer that two lines earlier had potentially been set as an
error pointer.

These issues could be individually fixed, but when it has this many
issues, I'm just reverting it instead of waiting for fixes.

Link: https://lore.kernel.org/linux-mm/20211111084617.6746-1-ajaygargnsit@gmail.com/
Reported-by: Ajay Garg <ajaygargnsit@gmail.com>
Reported-by: Jens Axboe <axboe@kernel.dk>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-13 12:03:03 -08:00
Linus Torvalds
0f7ddea622 netfs, 9p, afs and ceph (partial) foliation
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEqG5UsNXhtOCrfGQP+7dXa6fLC2sFAmGNO7sACgkQ+7dXa6fL
 C2sDTA//SLJBMoY719Z/RvZcZb3PUkuwYtqu8j/F6C1n231yg5TrlkchslV635Ph
 4lUuy/+pEVtsWot4JBxBsziBsi5WCjucn6opFAO2UOyT0aiE9ucY2MG+fNo6/b5k
 RRGqbEODKHScC7pm00AJlqd8gJUvHz6Zy08KetHvkSI4bqBz5VpKxDSNxcWvsbx1
 T6FMY+E61vSd0bEOp1/sZ1gRKK5nG9BJrba9V/MuOzj94MqVd9Ajdarr2vfQ7IyS
 Qe16rOBM8u6oCRJqRcwdz2Ma0Zf/0Bm6JpoP7LsEdbzXLKPiHPWM6kNd9WZFmMt1
 KFGGC3xG3Yxufasdpf5KCa6wlw1U5hWVITqRubHGxg49IdnrwxNK2zLqpJNr/lZC
 vsOg31PkAWmJiMCAxhwL+u++Qar27jlXcdiO6tyqIDYHWyzwGWqF5zlzZ46NR26W
 SX7oB36drIzH+UMDqxKGti2hRYTPKKwjCJ6p0EfhEYQ0oGa/bNFJA3bPxupJCkJe
 PD0pnXdEmhKwvY0fLH6Ghr/PAckQttstTFpaHZ40XFzglgd3Sm5DEcg2Xm38LQ+n
 4elMUA+c807ZTDLSDkGTL9QKPmgoM3AFoAsVxV9eqtEYAzYdnYM1GJ0CGOWM1lvs
 vDrB7rqn/CFB6ks8k1BOalq2DTmPVU1I1f1GwnkyOiVtlxyrslk=
 =K23c
 -----END PGP SIGNATURE-----

Merge tag 'netfs-folio-20211111' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull netfs, 9p, afs and ceph (partial) foliation from David Howells:
 "This converts netfslib, 9p and afs to use folios. It also partially
  converts ceph so that it uses folios on the boundaries with netfslib.

  To help with this, a couple of folio helper functions are added in the
  first two patches.

  These patches don't touch fscache and cachefiles as I intend to remove
  all the code that deals with pages directly from there. Only nfs and
  cifs are using the old fscache I/O API now. The new API uses iov_iter
  instead.

  Thanks to Jeff Layton, Dominique Martinet and AuriStor for testing and
  retesting the patches"

* tag 'netfs-folio-20211111' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  afs: Use folios in directory handling
  netfs, 9p, afs, ceph: Use folios
  folio: Add a function to get the host inode for a folio
  folio: Add a function to change the private data attached to a folio
2021-11-13 11:15:15 -08:00
Linus Torvalds
dbf4989618 Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:
 "The post-linux-next material.

  7 patches.

  Subsystems affected by this patch series (all mm): debug,
  slab-generic, migration, memcg, and kasan"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  kasan: add kasan mode messages when kasan init
  mm: unexport {,un}lock_page_memcg
  mm: unexport folio_memcg_{,un}lock
  mm/migrate.c: remove MIGRATE_PFN_LOCKED
  mm: migrate: simplify the file-backed pages validation when migrating its mapping
  mm: allow only SLUB on PREEMPT_RT
  mm/page_owner.c: modify the type of argument "order" in some functions
2021-11-11 14:31:47 -08:00
Linus Torvalds
f54ca91fe6 Networking fixes for 5.16-rc1, including fixes from bpf, can
and netfilter.
 
 Current release - regressions:
 
  - bpf: do not reject when the stack read size is different
    from the tracked scalar size
 
  - net: fix premature exit from NAPI state polling in napi_disable()
 
  - riscv, bpf: fix RV32 broken build, and silence RV64 warning
 
 Current release - new code bugs:
 
  - net: fix possible NULL deref in sock_reserve_memory
 
  - amt: fix error return code in amt_init(); fix stopping the workqueue
 
  - ax88796c: use the correct ioctl callback
 
 Previous releases - always broken:
 
  - bpf: stop caching subprog index in the bpf_pseudo_func insn
 
  - security: fixups for the security hooks in sctp
 
  - nfc: add necessary privilege flags in netlink layer, limit operations
    to admin only
 
  - vsock: prevent unnecessary refcnt inc for non-blocking connect
 
  - net/smc: fix sk_refcnt underflow on link down and fallback
 
  - nfnetlink_queue: fix OOB when mac header was cleared
 
  - can: j1939: ignore invalid messages per standard
 
  - bpf, sockmap:
    - fix race in ingress receive verdict with redirect to self
    - fix incorrect sk_skb data_end access when src_reg = dst_reg
    - strparser, and tls are reusing qdisc_skb_cb and colliding
 
  - ethtool: fix ethtool msg len calculation for pause stats
 
  - vlan: fix a UAF in vlan_dev_real_dev() when ref-holder tries
    to access an unregistering real_dev
 
  - udp6: make encap_rcv() bump the v6 not v4 stats
 
  - drv: prestera: add explicit padding to fix m68k build
 
  - drv: felix: fix broken VLAN-tagged PTP under VLAN-aware bridge
 
  - drv: mvpp2: fix wrong SerDes reconfiguration order
 
 Misc & small latecomers:
 
  - ipvs: auto-load ipvs on genl access
 
  - mctp: sanity check the struct sockaddr_mctp padding fields
 
  - libfs: support RENAME_EXCHANGE in simple_rename()
 
  - avoid double accounting for pure zerocopy skbs
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEE6jPA+I1ugmIBA4hXMUZtbf5SIrsFAmGNQdwACgkQMUZtbf5S
 IrsiMQ//f66lTJ8PJ5Qj70hX9dC897olx7uGHB9eiKoyOcJI459hFlfXwRU2T4Tf
 fPNwPNUQ9Mynw9tX/jWEi+7zd6r6TSHGXK49U9/rIbQ95QjKY4LHowIE63x+vPl2
 5Cpf+80zXC3DUX1fijgyG1ujnU3kBaqopTxDLmlsHw2PGkwT5Ox1DUwkhc370eEL
 xlpq3PYGWA8/AQNyhSVBkG/UmoLaq0jYNP5yVcOj4jGjgcgLe1SLrqczENr35QHZ
 cRkuBsFBMBZF7wSX2f9qQIB/+b1pcLlD9IO+K3S7Ruq+rUd7qfL/tmwNxEh0axYK
 AyIun1Bxcy7QJGjtpGAz+Ku7jS9T3HxzyxhqilQo3co8jAW0WJ1YwHl+XPgQXyjV
 DLG6Vxt4syiwsoSXGn8MQugs4nlBT+0qWl8YamIR+o7KkAYPc2QWkXlzEDfNeIW8
 JNCZA3sy7VGi1ytorZGx16sQsEWnyRG9a6/WV20Dr+HVs1SKPcFzIfG6mVngR07T
 mQMHnbAF6Z5d8VTcPQfMxd7UH48s1bHtk5lcSTa3j0Cw+GkA6ytTmjPdJ1qRcdkH
 dl9jAfADe4O6frG+9XH7FEFqhmkghVI7bOCA4ZOhClVaIcDGgEZc2y7sY9/oZ7P4
 KXBD2R5X1caCUM0UtzwL7/8ddOtPtHIrFnhY+7+I6ijt9qmI0BY=
 =Ttgq
 -----END PGP SIGNATURE-----

Merge tag 'net-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Including fixes from bpf, can and netfilter.

  Current release - regressions:

   - bpf: do not reject when the stack read size is different from the
     tracked scalar size

   - net: fix premature exit from NAPI state polling in napi_disable()

   - riscv, bpf: fix RV32 broken build, and silence RV64 warning

  Current release - new code bugs:

   - net: fix possible NULL deref in sock_reserve_memory

   - amt: fix error return code in amt_init(); fix stopping the
     workqueue

   - ax88796c: use the correct ioctl callback

  Previous releases - always broken:

   - bpf: stop caching subprog index in the bpf_pseudo_func insn

   - security: fixups for the security hooks in sctp

   - nfc: add necessary privilege flags in netlink layer, limit
     operations to admin only

   - vsock: prevent unnecessary refcnt inc for non-blocking connect

   - net/smc: fix sk_refcnt underflow on link down and fallback

   - nfnetlink_queue: fix OOB when mac header was cleared

   - can: j1939: ignore invalid messages per standard

   - bpf, sockmap:
      - fix race in ingress receive verdict with redirect to self
      - fix incorrect sk_skb data_end access when src_reg = dst_reg
      - strparser, and tls are reusing qdisc_skb_cb and colliding

   - ethtool: fix ethtool msg len calculation for pause stats

   - vlan: fix a UAF in vlan_dev_real_dev() when ref-holder tries to
     access an unregistering real_dev

   - udp6: make encap_rcv() bump the v6 not v4 stats

   - drv: prestera: add explicit padding to fix m68k build

   - drv: felix: fix broken VLAN-tagged PTP under VLAN-aware bridge

   - drv: mvpp2: fix wrong SerDes reconfiguration order

  Misc & small latecomers:

   - ipvs: auto-load ipvs on genl access

   - mctp: sanity check the struct sockaddr_mctp padding fields

   - libfs: support RENAME_EXCHANGE in simple_rename()

   - avoid double accounting for pure zerocopy skbs"

* tag 'net-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (123 commits)
  selftests/net: udpgso_bench_rx: fix port argument
  net: wwan: iosm: fix compilation warning
  cxgb4: fix eeprom len when diagnostics not implemented
  net: fix premature exit from NAPI state polling in napi_disable()
  net/smc: fix sk_refcnt underflow on linkdown and fallback
  net/mlx5: Lag, fix a potential Oops with mlx5_lag_create_definer()
  gve: fix unmatched u64_stats_update_end()
  net: ethernet: lantiq_etop: Fix compilation error
  selftests: forwarding: Fix packet matching in mirroring selftests
  vsock: prevent unnecessary refcnt inc for nonblocking connect
  net: marvell: mvpp2: Fix wrong SerDes reconfiguration order
  net: ethernet: ti: cpsw_ale: Fix access to un-initialized memory
  net: stmmac: allow a tc-taprio base-time of zero
  selftests: net: test_vxlan_under_vrf: fix HV connectivity test
  net: hns3: allow configure ETS bandwidth of all TCs
  net: hns3: remove check VF uc mac exist when set by PF
  net: hns3: fix some mac statistics is always 0 in device version V2
  net: hns3: fix kernel crash when unload VF while it is being reset
  net: hns3: sync rx ring head in echo common pull
  net: hns3: fix pfc packet number incorrect after querying pfc parameters
  ...
2021-11-11 09:49:36 -08:00
Kuan-Ying Lee
b873e98681 kasan: add kasan mode messages when kasan init
There are multiple kasan modes.  It makes sense that we add some
messages to know which kasan mode is active when booting up [1].

Link: https://bugzilla.kernel.org/show_bug.cgi?id=212195 [1]
Link: https://lkml.kernel.org/r/20211020094850.4113-1-Kuan-Ying.Lee@mediatek.com
Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: Yee Lee <yee.lee@mediatek.com>
Cc: Nicholas Tang <nicholas.tang@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-11 09:34:35 -08:00
Christoph Hellwig
ab2f9d2d36 mm: unexport {,un}lock_page_memcg
These are only used in built-in core mm code.

Link: https://lkml.kernel.org/r/20210820095815.445392-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-11 09:34:35 -08:00
Christoph Hellwig
913ffbdd99 mm: unexport folio_memcg_{,un}lock
Patch series "unexport memcg locking helpers".

Neither the old page-based nor the new folio-based memcg locking helpers
are used in modular code at all, so drop the exports.

This patch (of 2):

folio_memcg_{,un}lock are only used in built-in core mm code.

Link: https://lkml.kernel.org/r/20210820095815.445392-1-hch@lst.de
Link: https://lkml.kernel.org/r/20210820095815.445392-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-11 09:34:35 -08:00
Alistair Popple
ab09243aa9 mm/migrate.c: remove MIGRATE_PFN_LOCKED
MIGRATE_PFN_LOCKED is used to indicate to migrate_vma_prepare() that a
source page was already locked during migrate_vma_collect().  If it
wasn't then the a second attempt is made to lock the page.  However if
the first attempt failed it's unlikely a second attempt will succeed,
and the retry adds complexity.  So clean this up by removing the retry
and MIGRATE_PFN_LOCKED flag.

Destination pages are also meant to have the MIGRATE_PFN_LOCKED flag
set, but nothing actually checks that.

Link: https://lkml.kernel.org/r/20211025041608.289017-1-apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-11 09:34:35 -08:00
Baolin Wang
0ef0246214 mm: migrate: simplify the file-backed pages validation when migrating its mapping
There is no need to validate the file-backed page's refcount before
trying to freeze the page's expected refcount, instead we can rely on
the folio_ref_freeze() to validate if the page has the expected refcount
before migrating its mapping.

Moreover we are always under the page lock when migrating the page
mapping, which means nowhere else can remove it from the page cache, so
we can remove the xas_load() validation under the i_pages lock.

Link: https://lkml.kernel.org/r/cover.1629447552.git.baolin.wang@linux.alibaba.com
Link: https://lkml.kernel.org/r/df4c129fd8e86a95dbc55f4663d77441cc0d3bd1.1629447552.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-11 09:34:35 -08:00
Yixuan Cao
0093de693f mm/page_owner.c: modify the type of argument "order" in some functions
The type of "order" in struct page_owner is unsigned short.
However, it is unsigned int in the following 3 functions:

  __reset_page_owner
  __set_page_owner_handle
  __set_page_owner_handle

The type of "order" in argument list is unsigned int, which is
inconsistent.

[akpm@linux-foundation.org: update include/linux/page_owner.h]

Link: https://lkml.kernel.org/r/20211020125945.47792-1-caoyixuan2019@email.szu.edu.cn
Signed-off-by: Yixuan Cao <caoyixuan2019@email.szu.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-11 09:34:35 -08:00
Linus Torvalds
6752de1aeb pidfd.v5.16
-----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCYYvE0wAKCRCRxhvAZXjc
 oo36AQCQRC9+LsfBsfoqrrdfWqp9ifs9DuytUg+CTftsy1Pn0QD/ZtySkNx9mnNl
 0/lSTN5dJBfEYm6Xcfxuu/vu/iauhw0=
 =dY6T
 -----END PGP SIGNATURE-----

Merge tag 'pidfd.v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull pidfd updates from Christian Brauner:
 "Various places in the kernel have picked up pidfds.

  The two most recent additions have probably been the ability to use
  pidfds in bpf maps and the usage of pidfds in mm-based syscalls such
  as process_mrelease() and process_madvise().

  The same pattern to turn a pidfd into a struct task exists in two
  places. One of those places used PIDTYPE_TGID while the other one used
  PIDTYPE_PID even though it is clearly documented in all pidfd-helpers
  that pidfds __currently__ only refer to thread-group leaders (subject
  to change in the future if need be).

  This isn't a bug per se but has the potential to be one if we allow
  pidfds to refer to individual threads. If that happens we want to
  audit all codepaths that make use of them to ensure they can deal with
  pidfds refering to individual threads.

  This adds a simple helper to turn a pidfd into a struct task making it
  easy to grep for such places. Plus, it gets rid of code-duplication"

* tag 'pidfd.v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  mm: use pidfd_get_task()
  pid: add pidfd_get_task() helper
2021-11-10 16:02:08 -08:00
David Howells
452c472e26 folio: Add a function to get the host inode for a folio
Add a convenience function, folio_inode() that will get the host inode from
a folio's mapping.

Changes:
 ver #3:
  - Fix mistake in function description[2].
 ver #2:
  - Fix contradiction between doc and implementation by disallowing use
    with swap caches[1].

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Dominique Martinet <asmadeus@codewreck.org>
Tested-by: kafs-testing@auristor.com
Link: https://lore.kernel.org/r/YST8OcVNy02Rivbm@casper.infradead.org/ [1]
Link: https://lore.kernel.org/r/YYKLkBwQdtn4ja+i@casper.infradead.org/ [2]
Link: https://lore.kernel.org/r/162880453171.3369675.3704943108660112470.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/162981151155.1901565.7010079316994382707.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/163005744370.2472992.18324470937328925723.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163584184628.4023316.9386282630968981869.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/163649325519.309189.15072332908703129455.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/163657850401.834781.1031963517399283294.stgit@warthog.procyon.org.uk/ # v5
2021-11-10 21:16:52 +00:00
Linus Torvalds
89fa0be0a0 arm64 fixes for -rc1
- Fix double-evaluation of 'pte' macro argument when using 52-bit PAs
 
 - Fix signedness of some MTE prctl PR_* constants
 
 - Fix kmemleak memory usage by skipping early pgtable allocations
 
 - Fix printing of CPU feature register strings
 
 - Remove redundant -nostdlib linker flag for vDSO binaries
 -----BEGIN PGP SIGNATURE-----
 
 iQFEBAABCgAuFiEEPxTL6PPUbjXGY88ct6xw3ITBYzQFAmGL8ukQHHdpbGxAa2Vy
 bmVsLm9yZwAKCRC3rHDchMFjNB0XCADIFxVeLM3YMPsnDC6ttmGp/w1TXh5RoNBm
 IY5utdu8ybdrdCYO//Z6i7rQiYwPBRbR8Xts1LAfZDVuD/IPKqxiY+wjMe9FYu0U
 lb14dnT5iI7L3l0yo/5s1EC8FC/pfCMwi50+trAS5H5jo2wg/+6B/bgbymzTd1ZB
 vzVVzyGv1L/3xKHT4uEDjY1jMPRBH4Ugx2bJ1tzRzsC3Gz0D7ZeVd1Dg3ftPMsqI
 MA4Q5QeE9MsafcV8sKDRLnzNSYEr50goA0xtCre81VmJDNcm/y6UybUCF75KU72M
 kAOImXs0+wrDqNIocYgYlSWRu9xjw8qjoxjnyqikFx47HBesjY8T
 =pHQk
 -----END PGP SIGNATURE-----

Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Will Deacon:

 - Fix double-evaluation of 'pte' macro argument when using 52-bit PAs

 - Fix signedness of some MTE prctl PR_* constants

 - Fix kmemleak memory usage by skipping early pgtable allocations

 - Fix printing of CPU feature register strings

 - Remove redundant -nostdlib linker flag for vDSO binaries

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: pgtable: make __pte_to_phys/__phys_to_pte_val inline functions
  arm64: Track no early_pgtable_alloc() for kmemleak
  arm64: mte: change PR_MTE_TCF_NONE back into an unsigned long
  arm64: vdso: remove -nostdlib compiler flag
  arm64: arm64_ftr_reg->name may not be a human-readable string
2021-11-10 11:29:30 -08:00
Linus Torvalds
59a2ceeef6 Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:
 "87 patches.

  Subsystems affected by this patch series: mm (pagecache and hugetlb),
  procfs, misc, MAINTAINERS, lib, checkpatch, binfmt, kallsyms, ramfs,
  init, codafs, nilfs2, hfs, crash_dump, signals, seq_file, fork,
  sysvfs, kcov, gdb, resource, selftests, and ipc"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (87 commits)
  ipc/ipc_sysctl.c: remove fallback for !CONFIG_PROC_SYSCTL
  ipc: check checkpoint_restore_ns_capable() to modify C/R proc files
  selftests/kselftest/runner/run_one(): allow running non-executable files
  virtio-mem: disallow mapping virtio-mem memory via /dev/mem
  kernel/resource: disallow access to exclusive system RAM regions
  kernel/resource: clean up and optimize iomem_is_exclusive()
  scripts/gdb: handle split debug for vmlinux
  kcov: replace local_irq_save() with a local_lock_t
  kcov: avoid enable+disable interrupts if !in_task()
  kcov: allocate per-CPU memory on the relevant node
  Documentation/kcov: define `ip' in the example
  Documentation/kcov: include types.h in the example
  sysv: use BUILD_BUG_ON instead of runtime check
  kernel/fork.c: unshare(): use swap() to make code cleaner
  seq_file: fix passing wrong private data
  seq_file: move seq_escape() to a header
  signal: remove duplicate include in signal.h
  crash_dump: remove duplicate include in crash_dump.h
  crash_dump: fix boolreturn.cocci warning
  hfs/hfsplus: use WARN_ON for sanity check
  ...
2021-11-09 10:11:53 -08:00
David Hildenbrand
a9e7b8d4f6 kernel/resource: disallow access to exclusive system RAM regions
virtio-mem dynamically exposes memory inside a device memory region as
system RAM to Linux, coordinating with the hypervisor which parts are
actually "plugged" and consequently usable/accessible.

On the one hand, the virtio-mem driver adds/removes whole memory blocks,
creating/removing busy IORESOURCE_SYSTEM_RAM resources, on the other
hand, it logically (un)plugs memory inside added memory blocks,
dynamically either exposing them to the buddy or hiding them from the
buddy and marking them PG_offline.

In contrast to physical devices, like a DIMM, the virtio-mem driver is
required to actually make use of any of the device-provided memory,
because it performs the handshake with the hypervisor.  virtio-mem
memory cannot simply be access via /dev/mem without a driver.

There is no safe way to:
a) Access plugged memory blocks via /dev/mem, as they might contain
   unplugged holes or might get silently unplugged by the virtio-mem
   driver and consequently turned inaccessible.
b) Access unplugged memory blocks via /dev/mem because the virtio-mem
   driver is required to make them actually accessible first.

The virtio-spec states that unplugged memory blocks MUST NOT be written,
and only selected unplugged memory blocks MAY be read.  We want to make
sure, this is the case in sane environments -- where the virtio-mem driver
was loaded.

We want to make sure that in a sane environment, nobody "accidentially"
accesses unplugged memory inside the device managed region.  For example,
a user might spot a memory region in /proc/iomem and try accessing it via
/dev/mem via gdb or dumping it via something else.  By the time the mmap()
happens, the memory might already have been removed by the virtio-mem
driver silently: the mmap() would succeeed and user space might
accidentially access unplugged memory.

So once the driver was loaded and detected the device along the
device-managed region, we just want to disallow any access via /dev/mem to
it.

In an ideal world, we would mark the whole region as busy ("owned by a
driver") and exclude it; however, that would be wrong, as we don't really
have actual system RAM at these ranges added to Linux ("busy system RAM").
Instead, we want to mark such ranges as "not actual busy system RAM but
still soft-reserved and prepared by a driver for future use."

Let's teach iomem_is_exclusive() to reject access to any range with
"IORESOURCE_SYSTEM_RAM | IORESOURCE_EXCLUSIVE", even if not busy and even
if "iomem=relaxed" is set.  Introduce EXCLUSIVE_SYSTEM_RAM to make it
easier for applicable drivers to depend on this setting in their Kconfig.

For now, there are no applicable ranges and we'll modify virtio-mem next
to properly set IORESOURCE_EXCLUSIVE on the parent resource container it
creates to contain all actual busy system RAM added via
add_memory_driver_managed().

Link: https://lkml.kernel.org/r/20210920142856.17758-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-09 10:02:52 -08:00
Kefeng Wang
3298cbe804 mm: kasan: use is_kernel() helper
Directly use is_kernel() helper in kernel_or_module_addr().

Link: https://lkml.kernel.org/r/20210930071143.63410-8-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-09 10:02:51 -08:00
Imran Khan
0f68d45ef4 lib, stackdepot: add helper to print stack entries into buffer
To print stack entries into a buffer, users of stackdepot, first get a
list of stack entries using stack_depot_fetch and then print this list
into a buffer using stack_trace_snprint.  Provide a helper in stackdepot
for this purpose.  Also change above mentioned users to use this helper.

[imran.f.khan@oracle.com: fix build error]
  Link: https://lkml.kernel.org/r/20210915175321.3472770-4-imran.f.khan@oracle.com
[imran.f.khan@oracle.com: export stack_depot_snprint() to modules]
  Link: https://lkml.kernel.org/r/20210916133535.3592491-4-imran.f.khan@oracle.com

Link: https://lkml.kernel.org/r/20210915014806.3206938-4-imran.f.khan@oracle.com
Signed-off-by: Imran Khan <imran.f.khan@oracle.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Jani Nikula <jani.nikula@intel.com>	[i915]
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-09 10:02:50 -08:00
Imran Khan
505be48165 lib, stackdepot: add helper to print stack entries
To print a stack entries, users of stackdepot, first use stack_depot_fetch
to get a list of stack entries and then use stack_trace_print to print
this list.  Provide a helper in stackdepot to print stack entries based on
stackdepot handle.  Also change above mentioned users to use this helper.

Link: https://lkml.kernel.org/r/20210915014806.3206938-3-imran.f.khan@oracle.com
Signed-off-by: Imran Khan <imran.f.khan@oracle.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-09 10:02:50 -08:00
zhangyiru
83c1fd763b mm,hugetlb: remove mlock ulimit for SHM_HUGETLB
Commit 21a3c273f8 ("mm, hugetlb: add thread name and pid to
SHM_HUGETLB mlock rlimit warning") marked this as deprecated in 2012,
but it is not deleted yet.

Mike says he still sees that message in log files on occasion, so maybe we
should preserve this warning.

Also remove hugetlbfs related user_shm_unlock in ipc/shm.c and remove the
user_shm_unlock after out.

Link: https://lkml.kernel.org/r/20211103105857.25041-1-zhangyiru3@huawei.com
Signed-off-by: zhangyiru <zhangyiru3@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Liu Zixian <liuzixian4@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: wuxu.wu <wuxu.wu@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-09 10:02:48 -08:00
Johannes Weiner
51b8c1fe25 vfs: keep inodes with page cache off the inode shrinker LRU
Historically (pre-2.5), the inode shrinker used to reclaim only empty
inodes and skip over those that still contained page cache.  This caused
problems on highmem hosts: struct inode could put fill lowmem zones
before the cache was getting reclaimed in the highmem zones.

To address this, the inode shrinker started to strip page cache to
facilitate reclaiming lowmem.  However, this comes with its own set of
problems: the shrinkers may drop actively used page cache just because
the inodes are not currently open or dirty - think working with a large
git tree.  It further doesn't respect cgroup memory protection settings
and can cause priority inversions between containers.

Nowadays, the page cache also holds non-resident info for evicted cache
pages in order to detect refaults.  We've come to rely heavily on this
data inside reclaim for protecting the cache workingset and driving swap
behavior.  We also use it to quantify and report workload health through
psi.  The latter in turn is used for fleet health monitoring, as well as
driving automated memory sizing of workloads and containers, proactive
reclaim and memory offloading schemes.

The consequences of dropping page cache prematurely is that we're seeing
subtle and not-so-subtle failures in all of the above-mentioned
scenarios, with the workload generally entering unexpected thrashing
states while losing the ability to reliably detect it.

To fix this on non-highmem systems at least, going back to rotating
inodes on the LRU isn't feasible.  We've tried (commit a76cf1a474
("mm: don't reclaim inodes with many attached pages")) and failed
(commit 69056ee6a8 ("Revert "mm: don't reclaim inodes with many
attached pages"")).

The issue is mostly that shrinker pools attract pressure based on their
size, and when objects get skipped the shrinkers remember this as
deferred reclaim work.  This accumulates excessive pressure on the
remaining inodes, and we can quickly eat into heavily used ones, or
dirty ones that require IO to reclaim, when there potentially is plenty
of cold, clean cache around still.

Instead, this patch keeps populated inodes off the inode LRU in the
first place - just like an open file or dirty state would.  An otherwise
clean and unused inode then gets queued when the last cache entry
disappears.  This solves the problem without reintroducing the reclaim
issues, and generally is a bit more scalable than having to wade through
potentially hundreds of thousands of busy inodes.

Locking is a bit tricky because the locks protecting the inode state
(i_lock) and the inode LRU (lru_list.lock) don't nest inside the
irq-safe page cache lock (i_pages.xa_lock).  Page cache deletions are
serialized through i_lock, taken before the i_pages lock, to make sure
depopulated inodes are queued reliably.  Additions may race with
deletions, but we'll check again in the shrinker.  If additions race
with the shrinker itself, we're protected by the i_lock: if find_inode()
or iput() win, the shrinker will bail on the elevated i_count or
I_REFERENCED; if the shrinker wins and goes ahead with the inode, it
will set I_FREEING and inhibit further igets(), which will cause the
other side to create a new instance of the inode instead.

Link: https://lkml.kernel.org/r/20210614211904.14420-4-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-09 10:02:48 -08:00
Qian Cai
c6975d7cab arm64: Track no early_pgtable_alloc() for kmemleak
After switched page size from 64KB to 4KB on several arm64 servers here,
kmemleak starts to run out of early memory pool due to a huge number of
those early_pgtable_alloc() calls:

  kmemleak_alloc_phys()
  memblock_alloc_range_nid()
  memblock_phys_alloc_range()
  early_pgtable_alloc()
  init_pmd()
  alloc_init_pud()
  __create_pgd_mapping()
  __map_memblock()
  paging_init()
  setup_arch()
  start_kernel()

Increased the default value of DEBUG_KMEMLEAK_MEM_POOL_SIZE by 4 times
won't be enough for a server with 200GB+ memory. There isn't much
interesting to check memory leaks for those early page tables and those
early memory mappings should not reference to other memory. Hence, no
kmemleak false positives, and we can safely skip tracking those early
allocations from kmemleak like we did in the commit fed84c7852
("mm/memblock.c: skip kmemleak for kasan_init()") without needing to
introduce complications to automatically scale the value depends on the
runtime memory size etc. After the patch, the default value of
DEBUG_KMEMLEAK_MEM_POOL_SIZE becomes sufficient again.

Signed-off-by: Qian Cai <quic_qiancai@quicinc.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Link: https://lore.kernel.org/r/20211105150509.7826-1-quic_qiancai@quicinc.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-11-08 10:05:22 +00:00
Linus Torvalds
512b7931ad Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:
 "257 patches.

  Subsystems affected by this patch series: scripts, ocfs2, vfs, and
  mm (slab-generic, slab, slub, kconfig, dax, kasan, debug, pagecache,
  gup, swap, memcg, pagemap, mprotect, mremap, iomap, tracing, vmalloc,
  pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, tools,
  memblock, oom-kill, hugetlbfs, migration, thp, readahead, nommu, ksm,
  vmstat, madvise, memory-hotplug, rmap, zsmalloc, highmem, zram,
  cleanups, kfence, and damon)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (257 commits)
  mm/damon: remove return value from before_terminate callback
  mm/damon: fix a few spelling mistakes in comments and a pr_debug message
  mm/damon: simplify stop mechanism
  Docs/admin-guide/mm/pagemap: wordsmith page flags descriptions
  Docs/admin-guide/mm/damon/start: simplify the content
  Docs/admin-guide/mm/damon/start: fix a wrong link
  Docs/admin-guide/mm/damon/start: fix wrong example commands
  mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on
  mm/damon: remove unnecessary variable initialization
  Documentation/admin-guide/mm/damon: add a document for DAMON_RECLAIM
  mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM)
  selftests/damon: support watermarks
  mm/damon/dbgfs: support watermarks
  mm/damon/schemes: activate schemes based on a watermarks mechanism
  tools/selftests/damon: update for regions prioritization of schemes
  mm/damon/dbgfs: support prioritization weights
  mm/damon/vaddr,paddr: support pageout prioritization
  mm/damon/schemes: prioritize regions within the quotas
  mm/damon/selftests: support schemes quotas
  mm/damon/dbgfs: support quotas of schemes
  ...
2021-11-06 14:08:17 -07:00
Changbin Du
658f9ae761 mm/damon: remove return value from before_terminate callback
Since the return value of 'before_terminate' callback is never used, we
make it have no return value.

Link: https://lkml.kernel.org/r/20211029005023.8895-1-changbin.du@gmail.com
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:46 -07:00
Colin Ian King
0107865541 mm/damon: fix a few spelling mistakes in comments and a pr_debug message
There are a few spelling mistakes in the code.  Fix these.

Link: https://lkml.kernel.org/r/20211028184157.614544-1-colin.i.king@gmail.com
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:46 -07:00
Changbin Du
0f91d13366 mm/damon: simplify stop mechanism
A kernel thread can exit gracefully with kthread_stop().  So we don't
need a new flag 'kdamond_stop'.  And to make sure the task struct is not
freed when accessing it, get reference to it before termination.

Link: https://lkml.kernel.org/r/20211027130517.4404-1-changbin.du@gmail.com
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:46 -07:00
Xin Hao
b5ca3e83dd mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on
When the ctx->adaptive_targets list is empty, I did some test on
monitor_on interface like this.

    # cat /sys/kernel/debug/damon/target_ids
    #
    # echo on > /sys/kernel/debug/damon/monitor_on
    # damon: kdamond (5390) starts

Though the ctx->adaptive_targets list is empty, but the kthread_run
still be called, and the kdamond.x thread still be created, this is
meaningless.

So there adds a judgment in 'dbgfs_monitor_on_write', if the
ctx->adaptive_targets list is empty, return -EINVAL.

Link: https://lkml.kernel.org/r/0a60a6e8ec9d71989e0848a4dc3311996ca3b5d4.1634720326.git.xhao@linux.alibaba.com
Signed-off-by: Xin Hao <xhao@linux.alibaba.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:46 -07:00
Xin Hao
a460a36034 mm/damon: remove unnecessary variable initialization
Patch series "mm/damon: Fix some small bugs", v4.

This patch (of 2):

In 'damon_va_apply_three_regions' there is no need to set variable 'i'
to zero.

Link: https://lkml.kernel.org/r/b7df8d3dad0943a37e01f60c441b1968b2b20354.1634720326.git.xhao@linux.alibaba.com
Link: https://lkml.kernel.org/r/cover.1634720326.git.xhao@linux.alibaba.com
Signed-off-by: Xin Hao <xhao@linux.alibaba.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:46 -07:00
SeongJae Park
43b0536cb4 mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM)
This implements a new kernel subsystem that finds cold memory regions
using DAMON and reclaims those immediately.  It is intended to be used
as proactive lightweigh reclamation logic for light memory pressure.
For heavy memory pressure, it could be inactivated and fall back to the
traditional page-scanning based reclamation.

It's implemented on top of DAMON framework to use the DAMON-based
Operation Schemes (DAMOS) feature.  It utilizes all the DAMOS features
including speed limit, prioritization, and watermarks.

It could be enabled and tuned in boot time via the kernel boot
parameter, and in run time via its module parameters
('/sys/module/damon_reclaim/parameters/') interface.

[yangyingliang@huawei.com: fix error return code in damon_reclaim_turn()]
  Link: https://lkml.kernel.org/r/20211025124500.2758060-1-yangyingliang@huawei.com

Link: https://lkml.kernel.org/r/20211019150731.16699-15-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:46 -07:00
SeongJae Park
ae666a6ddd mm/damon/dbgfs: support watermarks
This updates DAMON debugfs interface to support the watermarks based
schemes activation.  For this, now 'schemes' file receives five more
values.

Link: https://lkml.kernel.org/r/20211019150731.16699-13-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:45 -07:00
SeongJae Park
ee801b7dd7 mm/damon/schemes: activate schemes based on a watermarks mechanism
DAMON-based operation schemes need to be manually turned on and off.  In
some use cases, however, the condition for turning a scheme on and off
would depend on the system's situation.  For example, schemes for
proactive pages reclamation would need to be turned on when some memory
pressure is detected, and turned off when the system has enough free
memory.

For easier control of schemes activation based on the system situation,
this introduces a watermarks-based mechanism.  The client can describe
the watermark metric (e.g., amount of free memory in the system),
watermark check interval, and three watermarks, namely high, mid, and
low.  If the scheme is deactivated, it only gets the metric and compare
that to the three watermarks for every check interval.  If the metric is
higher than the high watermark, the scheme is deactivated.  If the
metric is between the mid watermark and the low watermark, the scheme is
activated.  If the metric is lower than the low watermark, the scheme is
deactivated again.  This is to allow users fall back to traditional
page-granularity mechanisms.

Link: https://lkml.kernel.org/r/20211019150731.16699-12-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:45 -07:00
SeongJae Park
f4a68b4a04 mm/damon/dbgfs: support prioritization weights
This allows DAMON debugfs interface users set the prioritization weights
by putting three more numbers to the 'schemes' file.

Link: https://lkml.kernel.org/r/20211019150731.16699-10-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:45 -07:00
SeongJae Park
198f0f4c58 mm/damon/vaddr,paddr: support pageout prioritization
This makes the default monitoring primitives for virtual address spaces
and the physical address sapce to support memory regions prioritization
for 'PAGEOUT' DAMOS action.  It calculates hotness of each region as
weighted sum of 'nr_accesses' and 'age' of the region and get the
priority score as reverse of the hotness, so that cold regions can be
paged out first.

Link: https://lkml.kernel.org/r/20211019150731.16699-9-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:45 -07:00
SeongJae Park
38683e0031 mm/damon/schemes: prioritize regions within the quotas
This makes DAMON apply schemes to regions having higher priority first,
if it cannot apply schemes to all regions due to the quotas.

The prioritization function should be implemented in the monitoring
primitives.  Those would commonly calculate the priority of the region
using attributes of regions, namely 'size', 'nr_accesses', and 'age'.
For example, some primitive would calculate the priority of each region
using a weighted sum of 'nr_accesses' and 'age' of the region.

The optimal weights would depend on give environments, so this makes
those customizable.  Nevertheless, the score calculation functions are
only encouraged to respect the weights, not mandated.

Link: https://lkml.kernel.org/r/20211019150731.16699-8-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:45 -07:00
SeongJae Park
d7d0ec85e9 mm/damon/dbgfs: support quotas of schemes
This makes the debugfs interface of DAMON support the scheme quotas by
chaning the format of the input for the schemes file.

Link: https://lkml.kernel.org/r/20211019150731.16699-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:45 -07:00
SeongJae Park
1cd2430300 mm/damon/schemes: implement time quota
The size quota feature of DAMOS is useful for IO resource-critical
systems, but not so intuitive for CPU time-critical systems.  Systems
using zram or zswap-like swap device would be examples.

To provide another intuitive ways for such systems, this implements
time-based quota for DAMON-based Operation Schemes.  If the quota is
set, DAMOS tries to use only up to the user-defined quota of CPU time
within a given time window.

Link: https://lkml.kernel.org/r/20211019150731.16699-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:45 -07:00
SeongJae Park
50585192bc mm/damon/schemes: skip already charged targets and regions
If DAMOS has stopped applying action in the middle of a group of memory
regions due to its size quota, it starts the work again from the
beginning of the address space in the next charge window.  If there is a
huge memory region at the beginning of the address space and it fulfills
the scheme's target data access pattern always, the action will applied
to only the region.

This mitigates the case by skipping memory regions that charged in
current charge window at the beginning of next charge window.

Link: https://lkml.kernel.org/r/20211019150731.16699-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:45 -07:00
SeongJae Park
2b8a248d58 mm/damon/schemes: implement size quota for schemes application speed control
There could be arbitrarily large memory regions fulfilling the target
data access pattern of a DAMON-based operation scheme.  In the case,
applying the action of the scheme could incur too high overhead.  To
provide an intuitive way for avoiding it, this implements a feature
called size quota.  If the quota is set, DAMON tries to apply the action
only up to the given amount of memory regions within a given time
window.

Link: https://lkml.kernel.org/r/20211019150731.16699-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:45 -07:00
SeongJae Park
57223ac295 mm/damon/paddr: support the pageout scheme
Introduction
============

This patchset 1) makes the engine for general data access
pattern-oriented memory management (DAMOS) be more useful for production
environments, and 2) implements a static kernel module for lightweight
proactive reclamation using the engine.

Proactive Reclamation
---------------------

On general memory over-committed systems, proactively reclaiming cold
pages helps saving memory and reducing latency spikes that incurred by
the direct reclaim or the CPU consumption of kswapd, while incurring
only minimal performance degradation[2].

A Free Pages Reporting[8] based memory over-commit virtualization system
would be one more specific use case.  In the system, the guest VMs
reports their free memory to host, and the host reallocates the reported
memory to other guests.  As a result, the system's memory utilization
can be maximized.  However, the guests could be not so memory-frugal,
because some kernel subsystems and user-space applications are designed
to use as much memory as available.  Then, guests would report only
small amount of free memory to host, results in poor memory utilization.
Running the proactive reclamation in such guests could help mitigating
this problem.

Google has also implemented this idea and using it in their data center.
They further proposed upstreaming it in LSFMM'19, and "the general
consensus was that, while this sort of proactive reclaim would be useful
for a number of users, the cost of this particular solution was too high
to consider merging it upstream"[3].  The cost mainly comes from the
coldness tracking.  Roughly speaking, the implementation periodically
scans the 'Accessed' bit of each page.  For the reason, the overhead
linearly increases as the size of the memory and the scanning frequency
grows.  As a result, Google is known to dedicating one CPU for the work.
That's a reasonable option to someone like Google, but it wouldn't be so
to some others.

DAMON and DAMOS: An engine for data access pattern-oriented memory management
-----------------------------------------------------------------------------

DAMON[4] is a framework for general data access monitoring.  Its
adaptive monitoring overhead control feature minimizes its monitoring
overhead.  It also let the upper-bound of the overhead be configurable
by clients, regardless of the size of the monitoring target memory.
While monitoring 70 GiB memory of a production system every 5
milliseconds, it consumes less than 1% single CPU time.  For this, it
could sacrify some of the quality of the monitoring results.
Nevertheless, the lower-bound of the quality is configurable, and it
uses a best-effort algorithm for better quality.  Our test results[5]
show the quality is practical enough.  From the production system
monitoring, we were able to find a 4 KiB region in the 70 GiB memory
that shows highest access frequency.

We normally don't monitor the data access pattern just for fun but to
improve something like memory management.  Proactive reclamation is one
such usage.  For such general cases, DAMON provides a feature called
DAMon-based Operation Schemes (DAMOS)[6].  It makes DAMON an engine for
general data access pattern oriented memory management.  Using this,
clients can ask DAMON to find memory regions of specific data access
pattern and apply some memory management action (e.g., page out, move to
head of the LRU list, use huge page, ...).  We call the request
'scheme'.

Proactive Reclamation on top of DAMON/DAMOS
-------------------------------------------

Therefore, by using DAMON for the cold pages detection, the proactive
reclamation's monitoring overhead issue can be solved.  Actually, we
previously implemented a version of proactive reclamation using DAMOS
and achieved noticeable improvements with our evaluation setup[5].
Nevertheless, it more for a proof-of-concept, rather than production
uses.  It supports only virtual address spaces of processes, and require
additional tuning efforts for given workloads and the hardware.  For the
tuning, we introduced a simple auto-tuning user space tool[8].  Google
is also known to using a ML-based similar approach for their fleets[2].
But, making it just works with intuitive knobs in the kernel would be
helpful for general users.

To this end, this patchset improves DAMOS to be ready for such
production usages, and implements another version of the proactive
reclamation, namely DAMON_RECLAIM, on top of it.

DAMOS Improvements: Aggressiveness Control, Prioritization, and Watermarks
--------------------------------------------------------------------------

First of all, the current version of DAMOS supports only virtual address
spaces.  This patchset makes it supports the physical address space for
the page out action.

Next major problem of the current version of DAMOS is the lack of the
aggressiveness control, which can results in arbitrary overhead.  For
example, if huge memory regions having the data access pattern of
interest are found, applying the requested action to all of the regions
could incur significant overhead.  It can be controlled by tuning the
target data access pattern with manual or automated approaches[2,7].
But, some people would prefer the kernel to just work with only
intuitive tuning or default values.

For such cases, this patchset implements a safeguard, namely time/size
quota.  Using this, the clients can specify up to how much time can be
used for applying the action, and/or up to how much memory regions the
action can be applied within a user-specified time duration.  A followup
question is, to which memory regions should the action applied within
the limits? We implement a simple regions prioritization mechanism for
each action and make DAMOS to apply the action to high priority regions
first.  It also allows clients tune the prioritization mechanism to use
different weights for size, access frequency, and age of memory regions.
This means we could use not only LRU but also LFU or some fancy
algorithms like CAR[9] with lightweight overhead.

Though DAMON is lightweight, someone would want to remove even the cold
pages monitoring overhead when it is unnecessary.  Currently, it should
manually turned on and off by clients, but some clients would simply
want to turn it on and off based on some metrics like free memory ratio
or memory fragmentation.  For such cases, this patchset implements a
watermarks-based automatic activation feature.  It allows the clients
configure the metric of their interest, and three watermarks of the
metric.  If the metric is higher than the high watermark or lower than
the low watermark, the scheme is deactivated.  If the metric is lower
than the mid watermark but higher than the low watermark, the scheme is
activated.

DAMON-based Reclaim
-------------------

Using the improved version of DAMOS, this patchset implements a static
kernel module called 'damon_reclaim'.  It finds memory regions that
didn't accessed for specific time duration and page out.  Consuming too
much CPU for the paging out operations, or doing pageout too frequently
can be critical for systems configuring their swap devices with
software-defined in-memory block devices like zram/zswap or total number
of writes limited devices like SSDs, respectively.  To avoid the
problems, the time/size quotas can be configured.  Under the quotas, it
pages out memory regions that didn't accessed longer first.  Also, to
remove the monitoring overhead under peaceful situation, and to fall
back to the LRU-list based page granularity reclamation when it doesn't
make progress, the three watermarks based activation mechanism is used,
with the free memory ratio as the watermark metric.

For convenient configurations, it provides several module parameters.
Using these, sysadmins can enable/disable it, and tune its parameters
including the coldness identification time threshold, the time/size
quotas and the three watermarks.

Evaluation
==========

In short, DAMON_RECLAIM with 50ms/s time quota and regions
prioritization on v5.15-rc5 Linux kernel with ZRAM swap device achieves
38.58% memory saving with only 1.94% runtime overhead.  For this,
DAMON_RECLAIM consumes only 4.97% of single CPU time.

Setup
-----

We evaluate DAMON_RECLAIM to show how each of the DAMOS improvements
make effect.  For this, we measure DAMON_RECLAIM's CPU consumption,
entire system memory footprint, total number of major page faults, and
runtime of 24 realistic workloads in PARSEC3 and SPLASH-2X benchmark
suites on my QEMU/KVM based virtual machine.  The virtual machine runs
on an i3.metal AWS instance, has 130GiB memory, and runs a linux kernel
built on latest -mm tree[1] plus this patchset.  It also utilizes a 4
GiB ZRAM swap device.  We repeats the measurement 5 times and use
averages.

[1] https://github.com/hnaz/linux-mm/tree/v5.15-rc5-mmots-2021-10-13-19-55

Detailed Results
----------------

The results are summarized in the below table.

With coldness identification threshold of 5 seconds, DAMON_RECLAIM
without the time quota-based speed limit achieves 47.21% memory saving,
but incur 4.59% runtime slowdown to the workloads on average.  For this,
DAMON_RECLAIM consumes about 11.28% single CPU time.

Applying time quotas of 200ms/s, 50ms/s, and 10ms/s without the regions
prioritization reduces the slowdown to 4.89%, 2.65%, and 1.5%,
respectively.  Time quota of 200ms/s (20%) makes no real change compared
to the quota unapplied version, because the quota unapplied version
consumes only 11.28% CPU time.  DAMON_RECLAIM's CPU utilization also
similarly reduced: 11.24%, 5.51%, and 2.01% of single CPU time.  That
is, the overhead is proportional to the speed limit.  Nevertheless, it
also reduces the memory saving because it becomes less aggressive.  In
detail, the three variants show 48.76%, 37.83%, and 7.85% memory saving,
respectively.

Applying the regions prioritization (page out regions that not accessed
longer first within the time quota) further reduces the performance
degradation.  Runtime slowdowns and total number of major page faults
increase has been 4.89%/218,690% -> 4.39%/166,136% (200ms/s),
2.65%/111,886% -> 1.94%/59,053% (50ms/s), and 1.5%/34,973.40% ->
2.08%/8,781.75% (10ms/s).  The runtime under 10ms/s time quota has
increased with prioritization, but apparently that's under the margin of
error.

    time quota   prioritization  memory_saving  cpu_util  slowdown  pgmajfaults overhead
    N            N               47.21%         11.28%    4.59%     194,802%
    200ms/s      N               48.76%         11.24%    4.89%     218,690%
    50ms/s       N               37.83%         5.51%     2.65%     111,886%
    10ms/s       N               7.85%          2.01%     1.5%      34,793.40%
    200ms/s      Y               50.08%         10.38%    4.39%     166,136%
    50ms/s       Y               38.58%         4.97%     1.94%     59,053%
    10ms/s       Y               3.63%          1.73%     2.08%     8,781.75%

Baseline and Complete Git Trees
===============================

The patches are based on the latest -mm tree
(v5.15-rc5-mmots-2021-10-13-19-55).  You can also clone the complete git tree
from:

    $ git clone git://github.com/sjp38/linux -b damon_reclaim/patches/v1

The web is also available:
https://git.kernel.org/pub/scm/linux/kernel/git/sj/linux.git/tag/?h=damon_reclaim/patches/v1

Sequence Of Patches
===================

The first patch makes DAMOS support the physical address space for the
page out action.  Following five patches (patches 2-6) implement the
time/size quotas.  Next four patches (patches 7-10) implement the memory
regions prioritization within the limit.  Then, three following patches
(patches 11-13) implement the watermarks-based schemes activation.

Finally, the last two patches (patches 14-15) implement and document the
DAMON-based reclamation using the advanced DAMOS.

[1] https://www.kernel.org/doc/html/v5.15-rc1/vm/damon/index.html
[2] https://research.google/pubs/pub48551/
[3] https://lwn.net/Articles/787611/
[4] https://damonitor.github.io
[5] https://damonitor.github.io/doc/html/latest/vm/damon/eval.html
[6] https://lore.kernel.org/linux-mm/20211001125604.29660-1-sj@kernel.org/
[7] https://github.com/awslabs/damoos
[8] https://www.kernel.org/doc/html/latest/vm/free_page_reporting.html
[9] https://www.usenix.org/conference/fast-04/car-clock-adaptive-replacement

This patch (of 15):

This makes the DAMON primitives for physical address space support the
pageout action for DAMON-based Operation Schemes.  With this commit,
hence, users can easily implement system-level data access-aware
reclamations using DAMOS.

[sj@kernel.org: fix missing-prototype build warning]
  Link: https://lkml.kernel.org/r/20211025064220.13904-1-sj@kernel.org

Link: https://lkml.kernel.org/r/20211019150731.16699-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20211019150731.16699-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Marco Elver <elver@google.com>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Greg Thelen <gthelen@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:45 -07:00
Rongwei Wang
9210622ab8 mm/damon/dbgfs: remove unnecessary variables
In some functions, it's unnecessary to declare 'err' and 'ret' variables
at the same time.  This patch mainly to simplify the issue of such
declarations by reusing one variable.

Link: https://lkml.kernel.org/r/20211014073014.35754-1-sj@kernel.org
Signed-off-by: Rongwei Wang <rongwei.wang@linux.alibaba.com>
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:45 -07:00
Rikard Falkeborn
199b50f4c9 mm/damon/vaddr: constify static mm_walk_ops
The only usage of these structs is to pass their addresses to
walk_page_range(), which takes a pointer to const mm_walk_ops as
argument.  Make them const to allow the compiler to put them in
read-only memory.

Link: https://lkml.kernel.org/r/20211014075042.17174-2-rikard.falkeborn@gmail.com
Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:45 -07:00
SeongJae Park
c026291ab8 mm/damon/dbgfs: support physical memory monitoring
This makes the 'damon-dbgfs' to support the physical memory monitoring,
in addition to the virtual memory monitoring.

Users can do the physical memory monitoring by writing a special
keyword, 'paddr' to the 'target_ids' debugfs file.  Then, DAMON will
check the special keyword and configure the monitoring context to run
with the primitives for the physical address space.

Unlike the virtual memory monitoring, the monitoring target region will
not be automatically set.  Therefore, users should also set the
monitoring target address region using the 'init_regions' debugfs file.

Also, note that the physical memory monitoring will not automatically
terminated.  The user should explicitly turn off the monitoring by
writing 'off' to the 'monitor_on' debugfs file.

Link: https://lkml.kernel.org/r/20211012205711.29216-7-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rienjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:45 -07:00
SeongJae Park
a28397beb5 mm/damon: implement primitives for physical address space monitoring
This implements the monitoring primitives for the physical memory
address space.  Internally, it uses the PTE Accessed bit, similar to
that of the virtual address spaces monitoring primitives.  It supports
only user memory pages, as idle pages tracking does.  If the monitoring
target physical memory address range contains non-user memory pages,
access check of the pages will do nothing but simply treat the pages as
not accessed.

Link: https://lkml.kernel.org/r/20211012205711.29216-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rienjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:45 -07:00
SeongJae Park
46c3a0accd mm/damon/vaddr: separate commonly usable functions
This moves functions in the default virtual address spaces monitoring
primitives that commonly usable from other address spaces like physical
address space into a header file.  Those will be reused by the physical
address space monitoring primitives which will be implemented by the
following commit.

[sj@kernel.org: include 'highmem.h' to fix a build failure]
  Link: https://lkml.kernel.org/r/20211014110848.5204-1-sj@kernel.org

Link: https://lkml.kernel.org/r/20211012205711.29216-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rienjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:44 -07:00
SeongJae Park
1c2e11bfa6 mm/damon/dbgfs-test: add a unit test case for 'init_regions'
This adds another test case for the new feature, 'init_regions'.

Link: https://lkml.kernel.org/r/20211012205711.29216-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rienjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:44 -07:00
SeongJae Park
90bebce9fc mm/damon/dbgfs: allow users to set initial monitoring target regions
Patch series "DAMON: Support Physical Memory Address Space Monitoring:.

DAMON currently supports only virtual address spaces monitoring.  It can
be easily extended for various use cases and address spaces by
configuring its monitoring primitives layer to use appropriate
primitives implementations, though.  This patchset implements monitoring
primitives for the physical address space monitoring using the
structure.

The first 3 patches allow the user space users manually set the
monitoring regions.  The 1st patch implements the feature in the
'damon-dbgfs'.  Then, patches for adding a unit tests (the 2nd patch)
and updating the documentation (the 3rd patch) follow.

Following 4 patches implement the physical address space monitoring
primitives.  The 4th patch makes some primitive functions for the
virtual address spaces primitives reusable.  The 5th patch implements
the physical address space monitoring primitives.  The 6th patch links
the primitives to the 'damon-dbgfs'.  Finally, 7th patch documents this
new features.

This patch (of 7):

Some 'damon-dbgfs' users would want to monitor only a part of the entire
virtual memory address space.  The program interface users in the kernel
space could use '->before_start()' callback or set the regions inside
the context struct as they want, but 'damon-dbgfs' users cannot.

For that reason, this introduces a new debugfs file called
'init_region'.  'damon-dbgfs' users can specify which initial monitoring
target address regions they want by writing special input to the file.
The input should describe each region in each line in the below form:

    <pid> <start address> <end address>

Note that the regions will be updated to cover entire memory mapped
regions after a 'regions update interval' is passed.  If you want the
regions to not be updated after the initial setting, you could set the
interval as a very long time, say, a few decades.

Link: https://lkml.kernel.org/r/20211012205711.29216-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20211012205711.29216-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Marco Elver <elver@google.com>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Greg Thelen <gthelen@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: David Rienjes <rientjes@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:44 -07:00
SeongJae Park
2f0b548c9f mm/damon/schemes: implement statistics feature
To tune the DAMON-based operation schemes, knowing how many and how
large regions are affected by each of the schemes will be helful.  Those
stats could be used for not only the tuning, but also monitoring of the
working set size and the number of regions, if the scheme does not
change the program behavior too much.

For the reason, this implements the statistics for the schemes.  The
total number and size of the regions that each scheme is applied are
exported to users via '->stat_count' and '->stat_sz' of 'struct damos'.
Admins can also check the number by reading 'schemes' debugfs file.  The
last two integers now represents the stats.  To allow collecting the
stats without changing the program behavior, this also adds new scheme
action, 'DAMOS_STAT'.  Note that 'DAMOS_STAT' is not only making no
memory operation actions, but also does not reset the age of regions.

Link: https://lkml.kernel.org/r/20211001125604.29660-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rienjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:44 -07:00
SeongJae Park
af122dd8f3 mm/damon/dbgfs: support DAMON-based Operation Schemes
This makes 'damon-dbgfs' to support the data access monitoring oriented
memory management schemes.  Users can read and update the schemes using
``<debugfs>/damon/schemes`` file.  The format is::

    <min/max size> <min/max access frequency> <min/max age> <action>

Link: https://lkml.kernel.org/r/20211001125604.29660-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rienjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:44 -07:00
SeongJae Park
6dea8add4d mm/damon/vaddr: support DAMON-based Operation Schemes
This makes DAMON's default primitives for virtual address spaces to
support DAMON-based Operation Schemes (DAMOS) by implementing actions
application functions and registering it to the monitoring context.  The
implementation simply links 'madvise()' for related DAMOS actions.  That
is, 'madvise(MADV_WILLNEED)' is called for 'WILLNEED' DAMOS action and
similar for other actions ('COLD', 'PAGEOUT', 'HUGEPAGE', 'NOHUGEPAGE').

So, the kernel space DAMON users can now use the DAMON-based
optimizations with only small amount of code.

Link: https://lkml.kernel.org/r/20211001125604.29660-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rienjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:44 -07:00
SeongJae Park
1f366e421c mm/damon/core: implement DAMON-based Operation Schemes (DAMOS)
In many cases, users might use DAMON for simple data access aware memory
management optimizations such as applying an operation scheme to a
memory region of a specific size having a specific access frequency for
a specific time.  For example, "page out a memory region larger than 100
MiB but having a low access frequency more than 10 minutes", or "Use THP
for a memory region larger than 2 MiB having a high access frequency for
more than 2 seconds".

Most simple form of the solution would be doing offline data access
pattern profiling using DAMON and modifying the application source code
or system configuration based on the profiling results.  Or, developing
a daemon constructed with two modules (one for access monitoring and the
other for applying memory management actions via mlock(), madvise(),
sysctl, etc) is imaginable.

To avoid users spending their time for implementation of such simple
data access monitoring-based operation schemes, this makes DAMON to
handle such schemes directly.  With this change, users can simply
specify their desired schemes to DAMON.  Then, DAMON will automatically
apply the schemes to the user-specified target processes.

Each of the schemes is composed with conditions for filtering of the
target memory regions and desired memory management action for the
target.  Specifically, the format is::

    <min/max size> <min/max access frequency> <min/max age> <action>

The filtering conditions are size of memory region, number of accesses
to the region monitored by DAMON, and the age of the region.  The age of
region is incremented periodically but reset when its addresses or
access frequency has significantly changed or the action of a scheme was
applied.  For the action, current implementation supports a few of
madvise()-like hints, ``WILLNEED``, ``COLD``, ``PAGEOUT``, ``HUGEPAGE``,
and ``NOHUGEPAGE``.

Because DAMON supports various address spaces and application of the
actions to a monitoring target region is dependent to the type of the
target address space, the application code should be implemented by each
primitives and registered to the framework.  Note that this only
implements the framework part.  Following commit will implement the
action applications for virtual address spaces primitives.

Link: https://lkml.kernel.org/r/20211001125604.29660-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rienjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:44 -07:00
SeongJae Park
fda504fade mm/damon/core: account age of target regions
Patch series "Implement Data Access Monitoring-based Memory Operation Schemes".

Introduction
============

DAMON[1] can be used as a primitive for data access aware memory
management optimizations.  For that, users who want such optimizations
should run DAMON, read the monitoring results, analyze it, plan a new
memory management scheme, and apply the new scheme by themselves.  Such
efforts will be inevitable for some complicated optimizations.

However, in many other cases, the users would simply want the system to
apply a memory management action to a memory region of a specific size
having a specific access frequency for a specific time.  For example,
"page out a memory region larger than 100 MiB keeping only rare accesses
more than 2 minutes", or "Do not use THP for a memory region larger than
2 MiB rarely accessed for more than 1 seconds".

To make the works easier and non-redundant, this patchset implements a
new feature of DAMON, which is called Data Access Monitoring-based
Operation Schemes (DAMOS).  Using the feature, users can describe the
normal schemes in a simple way and ask DAMON to execute those on its
own.

[1] https://damonitor.github.io

Evaluations
===========

DAMOS is accurate and useful for memory management optimizations.  An
experimental DAMON-based operation scheme for THP, 'ethp', removes
76.15% of THP memory overheads while preserving 51.25% of THP speedup.
Another experimental DAMON-based 'proactive reclamation' implementation,
'prcl', reduces 93.38% of residential sets and 23.63% of system memory
footprint while incurring only 1.22% runtime overhead in the best case
(parsec3/freqmine).

NOTE that the experimental THP optimization and proactive reclamation
are not for production but only for proof of concepts.

Please refer to the showcase web site's evaluation document[1] for
detailed evaluation setup and results.

[1] https://damonitor.github.io/doc/html/v34/vm/damon/eval.html

Long-term Support Trees
-----------------------

For people who want to test DAMON but using LTS kernels, there are
another couple of trees based on two latest LTS kernels respectively and
containing the 'damon/master' backports.

- For v5.4.y: https://git.kernel.org/sj/h/damon/for-v5.4.y
- For v5.10.y: https://git.kernel.org/sj/h/damon/for-v5.10.y

Sequence Of Patches
===================

The 1st patch accounts age of each region.  The 2nd patch implements the
core of the DAMON-based operation schemes feature.  The 3rd patch makes
the default monitoring primitives for virtual address spaces to support
the schemes.  From this point, the kernel space users can use DAMOS.
The 4th patch exports the feature to the user space via the debugfs
interface.  The 5th patch implements schemes statistics feature for
easier tuning of the schemes and runtime access pattern analysis, and
the 6th patch adds selftests for these changes.  Finally, the 7th patch
documents this new feature.

This patch (of 7):

DAMON can be used for data access pattern aware memory management
optimizations.  For that, users should run DAMON, read the monitoring
results, analyze it, plan a new memory management scheme, and apply the
new scheme by themselves.  It would not be too hard, but still require
some level of effort.  For complicated cases, this effort is inevitable.

That said, in many cases, users would simply want to apply an actions to
a memory region of a specific size having a specific access frequency
for a specific time.  For example, "page out a memory region larger than
100 MiB but having a low access frequency more than 10 minutes", or "Use
THP for a memory region larger than 2 MiB having a high access frequency
for more than 2 seconds".

For such optimizations, users will need to first account the age of each
region themselves.  To reduce such efforts, this implements a simple age
account of each region in DAMON.  For each aggregation step, DAMON
compares the access frequency with that from last aggregation and reset
the age of the region if the change is significant.  Else, the age is
incremented.  Also, in case of the merge of regions, the region
size-weighted average of the ages is set as the age of merged new
region.

Link: https://lkml.kernel.org/r/20211001125604.29660-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20211001125604.29660-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Marco Elver <elver@google.com>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Greg Thelen <gthelen@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: David Rienjes <rientjes@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:44 -07:00
Colin Ian King
7ec1992b89 mm/damon/core: nullify pointer ctx->kdamond with a NULL
Currently a plain integer is being used to nullify the pointer
ctx->kdamond.  Use NULL instead.  Cleans up sparse warning:

  mm/damon/core.c:317:40: warning: Using plain integer as NULL pointer

Link: https://lkml.kernel.org/r/20210925215908.181226-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:44 -07:00
Changbin Du
42e4cef5fe mm/damon: needn't hold kdamond_lock to print pid of kdamond
Just get the pid by 'current->pid'.  Meanwhile, to be symmetrical make
the 'starts' and 'finishes' logs both use debug level.

Link: https://lkml.kernel.org/r/20210927232432.17750-1-changbin.du@gmail.com
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:44 -07:00
Changbin Du
5f7fe2b9b8 mm/damon: remove unnecessary do_exit() from kdamond
Just return from the kthread function.

Link: https://lkml.kernel.org/r/20210927232421.17694-1-changbin.du@gmail.com
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Cc: SeongJae Park <sjpark@amazon.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:44 -07:00
SeongJae Park
704571f997 mm/damon/core: print kdamond start log in debug mode only
Logging of kdamond startup is using 'pr_info()' unnecessarily.  This
makes it to use 'pr_debug()' instead.

Link: https://lkml.kernel.org/r/20210917123958.3819-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: SeongJae Park <sjpark@amazon.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:44 -07:00
Geert Uytterhoeven
f24b062607 mm/damon: grammar s/works/work/
Correct a singular versus plural grammar mistake in the help text for
the DAMON_VADDR config symbol.

Link: https://lkml.kernel.org/r/20210914073451.3883834-1-geert@linux-m68k.org
Fixes: 3f49584b26 ("mm/damon: implement primitives for the virtual memory address spaces")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: SeongJae Park <sjpark@amazon.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:43 -07:00
Marco Elver
07e8481d3c kfence: always use static branches to guard kfence_alloc()
Regardless of KFENCE mode (CONFIG_KFENCE_STATIC_KEYS: either using
static keys to gate allocations, or using a simple dynamic branch),
always use a static branch to avoid the dynamic branch in kfence_alloc()
if KFENCE was disabled at boot.

For CONFIG_KFENCE_STATIC_KEYS=n, this now avoids the dynamic branch if
KFENCE was disabled at boot.

To simplify, also unifies the location where kfence_allocation_gate is
read-checked to just be inline in kfence_alloc().

Link: https://lkml.kernel.org/r/20211019102524.2807208-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:43 -07:00
Marco Elver
4933295622 kfence: shorten critical sections of alloc/free
Initializing memory and setting/checking the canary bytes is relatively
expensive, and doing so in the meta->lock critical sections extends the
duration with preemption and interrupts disabled unnecessarily.

Any reads to meta->addr and meta->size in kfence_guarded_alloc() and
kfence_guarded_free() don't require locking meta->lock as long as the
object is removed from the freelist: only kfence_guarded_alloc() sets
meta->addr and meta->size after removing it from the freelist, which
requires a preceding kfence_guarded_free() returning it to the list or
the initial state.

Therefore move reads to meta->addr and meta->size, including expensive
memory initialization using them, out of meta->lock critical sections.

Link: https://lkml.kernel.org/r/20210930153706.2105471-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:43 -07:00
Marco Elver
f51733e2fc kfence: test: use kunit_skip() to skip tests
Use the new kunit_skip() to skip tests if requirements were not met.  It
makes it easier to see in KUnit's summary if there were skipped tests.

Link: https://lkml.kernel.org/r/20210922182541.1372400-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Aleksandr Nogikh <nogikh@google.com>
Cc: Taras Madan <tarasmadan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:43 -07:00
Marco Elver
08f6b10630 kfence: limit currently covered allocations when pool nearly full
One of KFENCE's main design principles is that with increasing uptime,
allocation coverage increases sufficiently to detect previously
undetected bugs.

We have observed that frequent long-lived allocations of the same source
(e.g.  pagecache) tend to permanently fill up the KFENCE pool with
increasing system uptime, thus breaking the above requirement.  The
workaround thus far had been increasing the sample interval and/or
increasing the KFENCE pool size, but is no reliable solution.

To ensure diverse coverage of allocations, limit currently covered
allocations of the same source once pool utilization reaches 75%
(configurable via `kfence.skip_covered_thresh`) or above.  The effect is
retaining reasonable allocation coverage when the pool is close to full.

A side-effect is that this also limits frequent long-lived allocations
of the same source filling up the pool permanently.

Uniqueness of an allocation for coverage purposes is based on its
(partial) allocation stack trace (the source).  A Counting Bloom filter
is used to check if an allocation is covered; if the allocation is
currently covered, the allocation is skipped by KFENCE.

Testing was done using:

	(a) a synthetic workload that performs frequent long-lived
	    allocations (default config values; sample_interval=1;
	    num_objects=63), and

	(b) normal desktop workloads on an otherwise idle machine where
	    the problem was first reported after a few days of uptime
	    (default config values).

In both test cases the sampled allocation rate no longer drops to zero
at any point.  In the case of (b) we observe (after 2 days uptime) 15%
unique allocations in the pool, 77% pool utilization, with 20% "skipped
allocations (covered)".

[elver@google.com: simplify and just use hash_32(), use more random stack_hash_seed]
  Link: https://lkml.kernel.org/r/YU3MRGaCaJiYht5g@elver.google.com
[elver@google.com: fix 32 bit]

Link: https://lkml.kernel.org/r/20210923104803.2620285-4-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Alexander Potapenko <glider@google.com>
Cc: Aleksandr Nogikh <nogikh@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Taras Madan <tarasmadan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:43 -07:00
Marco Elver
a9ab52bbcb kfence: move saving stack trace of allocations into __kfence_alloc()
Move the saving of the stack trace of allocations into __kfence_alloc(),
so that the stack entries array can be used outside of
kfence_guarded_alloc() and we avoid potentially unwinding the stack
multiple times.

Link: https://lkml.kernel.org/r/20210923104803.2620285-3-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Alexander Potapenko <glider@google.com>
Cc: Aleksandr Nogikh <nogikh@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Taras Madan <tarasmadan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:43 -07:00
Marco Elver
9a19aeb566 kfence: count unexpectedly skipped allocations
Maintain a counter to count allocations that are skipped due to being
incompatible (oversized, incompatible gfp flags) or no capacity.

This is to compute the fraction of allocations that could not be
serviced by KFENCE, which we expect to be rare.

Link: https://lkml.kernel.org/r/20210923104803.2620285-2-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Alexander Potapenko <glider@google.com>
Cc: Aleksandr Nogikh <nogikh@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Taras Madan <tarasmadan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:43 -07:00
Stephen Kitt
53944f171a mm: remove HARDENED_USERCOPY_FALLBACK
This has served its purpose and is no longer used.  All usercopy
violations appear to have been handled by now, any remaining instances
(or new bugs) will cause copies to be rejected.

This isn't a direct revert of commit 2d891fbc3b ("usercopy: Allow
strict enforcement of whitelists"); since usercopy_fallback is
effectively 0, the fallback handling is removed too.

This also removes the usercopy_fallback module parameter on slab_common.

Link: https://github.com/KSPP/linux/issues/153
Link: https://lkml.kernel.org/r/20210921061149.1091163-1-steve@sk2.org
Signed-off-by: Stephen Kitt <steve@sk2.org>
Suggested-by: Kees Cook <keescook@chromium.org>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>	[defconfig change]
Acked-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E . Hallyn" <serge@hallyn.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:43 -07:00
Ira Weiny
d2c20e51e3 mm/highmem: remove deprecated kmap_atomic
kmap_atomic() is being deprecated in favor of kmap_local_page().

Replace the uses of kmap_atomic() within the highmem code.

On profiling clear_huge_page() using ftrace an improvement of 62% was
observed on the below setup.

Setup:-
Below data has been collected on Qualcomm's SM7250 SoC THP enabled
(kernel v4.19.113) with only CPU-0(Cortex-A55) and CPU-7(Cortex-A76)
switched on and set to max frequency, also DDR set to perf governor.

FTRACE Data:-

Base data:-
Number of iterations: 48
Mean of allocation time: 349.5 us
std deviation: 74.5 us

v4 data:-
Number of iterations: 48
Mean of allocation time: 131 us
std deviation: 32.7 us

The following simple userspace experiment to allocate
100MB(BUF_SZ) of pages and writing to it gave us a good insight,
we observed an improvement of 42% in allocation and writing timings.
-------------------------------------------------------------
Test code snippet
-------------------------------------------------------------
      clock_start();
      buf = malloc(BUF_SZ); /* Allocate 100 MB of memory */

        for(i=0; i < BUF_SZ_PAGES; i++)
        {
                *((int *)(buf + (i*PAGE_SIZE))) = 1;
        }
      clock_end();
-------------------------------------------------------------

Malloc test timings for 100MB anon allocation:-

Base data:-
Number of iterations: 100
Mean of allocation time: 31831 us
std deviation: 4286 us

v4 data:-
Number of iterations: 100
Mean of allocation time: 18193 us
std deviation: 4915 us

[willy@infradead.org: fix zero_user_segments()]
  Link: https://lkml.kernel.org/r/YYVhHCJcm2DM2G9u@casper.infradead.org

Link: https://lkml.kernel.org/r/20210204073255.20769-2-prathu.baronia@oneplus.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Prathu Baronia <prathu.baronia@oneplus.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:43 -07:00
Miaohe Lin
afe8605ca4 mm/zsmalloc.c: close race window between zs_pool_dec_isolated() and zs_unregister_migration()
There is one possible race window between zs_pool_dec_isolated() and
zs_unregister_migration() because wait_for_isolated_drain() checks the
isolated count without holding class->lock and there is no order inside
zs_pool_dec_isolated().  Thus the below race window could be possible:

  zs_pool_dec_isolated		zs_unregister_migration
    check pool->destroying != 0
				  pool->destroying = true;
				  smp_mb();
				  wait_for_isolated_drain()
				    wait for pool->isolated_pages == 0
    atomic_long_dec(&pool->isolated_pages);
    atomic_long_read(&pool->isolated_pages) == 0

Since we observe the pool->destroying (false) before atomic_long_dec()
for pool->isolated_pages, waking pool->migration_wait up is missed.

Fix this by ensure checking pool->destroying happens after the
atomic_long_dec(&pool->isolated_pages).

Link: https://lkml.kernel.org/r/20210708115027.7557-1-linmiaohe@huawei.com
Fixes: 701d678599 ("mm/zsmalloc.c: fix race condition in zs_destroy_pool")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Henry Burns <henryburns@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:43 -07:00
Alistair Popple
3d88705c10 mm/rmap.c: avoid double faults migrating device private pages
During migration special page table entries are installed for each page
being migrated.  These entries store the pfn and associated permissions
of ptes mapping the page being migarted.

Device-private pages use special swap pte entries to distinguish
read-only vs.  writeable pages which the migration code checks when
creating migration entries.  Normally this follows a fast path in
migrate_vma_collect_pmd() which correctly copies the permissions of
device-private pages over to migration entries when migrating pages back
to the CPU.

However the slow-path falls back to using try_to_migrate() which
unconditionally creates read-only migration entries for device-private
pages.  This leads to unnecessary double faults on the CPU as the new
pages are always mapped read-only even when they could be mapped
writeable.  Fix this by correctly copying device-private permissions in
try_to_migrate_one().

Link: https://lkml.kernel.org/r/20211018045247.3128058-1-apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reported-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:43 -07:00
David Hildenbrand
32befe9e27 mm/memory_hotplug: indicate MEMBLOCK_DRIVER_MANAGED with IORESOURCE_SYSRAM_DRIVER_MANAGED
Let's communicate driver-managed regions to memblock, to properly teach
kexec_file with CONFIG_ARCH_KEEP_MEMBLOCK to not place images on these
memory regions.

Link: https://lkml.kernel.org/r/20211004093605.5830-6-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Jianyong Wu <Jianyong.Wu@arm.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Shahab Vahedi <shahab@synopsys.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:42 -07:00
David Hildenbrand
f7892d8e28 memblock: add MEMBLOCK_DRIVER_MANAGED to mimic IORESOURCE_SYSRAM_DRIVER_MANAGED
Let's add a flag that corresponds to IORESOURCE_SYSRAM_DRIVER_MANAGED,
indicating that we're dealing with a memory region that is never
indicated in the firmware-provided memory map, but always detected and
added by a driver.

Similar to MEMBLOCK_HOTPLUG, most infrastructure has to treat such
memory regions like ordinary MEMBLOCK_NONE memory regions -- for
example, when selecting memory regions to add to the vmcore for dumping
in the crashkernel via for_each_mem_range().

However, especially kexec_file is not supposed to select such memblocks
via for_each_free_mem_range() / for_each_free_mem_range_reverse() to
place kexec images, similar to how we handle
IORESOURCE_SYSRAM_DRIVER_MANAGED without CONFIG_ARCH_KEEP_MEMBLOCK.

We'll make sure that memory hotplug code sets the flag where applicable
(IORESOURCE_SYSRAM_DRIVER_MANAGED) next.  This prepares architectures
that need CONFIG_ARCH_KEEP_MEMBLOCK, such as arm64, for virtio-mem
support.

Note that kexec *must not* indicate this memory to the second kernel and
*must not* place kexec-images on this memory.  Let's add a comment to
kexec_walk_memblock(), documenting how we handle MEMBLOCK_DRIVER_MANAGED
now just like using IORESOURCE_SYSRAM_DRIVER_MANAGED in
locate_mem_hole_callback() for kexec_walk_resources().

Also note that MEMBLOCK_HOTPLUG cannot be reused due to different
semantics:
	MEMBLOCK_HOTPLUG: memory is indicated as "System RAM" in the
	firmware-provided memory map and added to the system early during
	boot; kexec *has to* indicate this memory to the second kernel and
	can place kexec-images on this memory. After memory hotunplug,
	kexec has to be re-armed. We mostly ignore this flag when
	"movable_node" is not set on the kernel command line, because
	then we're told to not care about hotunpluggability of such
	memory regions.

	MEMBLOCK_DRIVER_MANAGED: memory is not indicated as "System RAM" in
	the firmware-provided memory map; this memory is always detected
	and added to the system by a driver; memory might not actually be
	physically hotunpluggable. kexec *must not* indicate this memory to
	the second kernel and *must not* place kexec-images on this memory.

Link: https://lkml.kernel.org/r/20211004093605.5830-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Jianyong Wu <Jianyong.Wu@arm.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Shahab Vahedi <shahab@synopsys.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:42 -07:00
David Hildenbrand
952eea9b01 memblock: allow to specify flags with memblock_add_node()
We want to specify flags when hotplugging memory.  Let's prepare to pass
flags to memblock_add_node() by adjusting all existing users.

Note that when hotplugging memory the system is already up and running
and we might have concurrent memblock users: for example, while we're
hotplugging memory, kexec_file code might search for suitable memory
regions to place kexec images.  It's important to add the memory
directly to memblock via a single call with the right flags, instead of
adding the memory first and apply flags later: otherwise, concurrent
memblock users might temporarily stumble over memblocks with wrong
flags, which will be important in a follow-up patch that introduces a
new flag to properly handle add_memory_driver_managed().

Link: https://lkml.kernel.org/r/20211004093605.5830-4-david@redhat.com
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Shahab Vahedi <shahab@synopsys.com>	[arch/arc]
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Jianyong Wu <Jianyong.Wu@arm.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:42 -07:00
David Hildenbrand
53d38316ab mm/memory_hotplug: handle memblock_add_node() failures in add_memory_resource()
Patch series "mm/memory_hotplug: full support for add_memory_driver_managed() with CONFIG_ARCH_KEEP_MEMBLOCK", v2.

Architectures that require CONFIG_ARCH_KEEP_MEMBLOCK=y, such as arm64,
don't cleanly support add_memory_driver_managed() yet.  Most
prominently, kexec_file can still end up placing kexec images on such
driver-managed memory, resulting in undesired behavior, for example,
having kexec images located on memory not part of the firmware-provided
memory map.

Teaching kexec to not place images on driver-managed memory is
especially relevant for virtio-mem.  Details can be found in commit
7b7b27214b ("mm/memory_hotplug: introduce
add_memory_driver_managed()").

Extend memblock with a new flag and set it from memory hotplug code when
applicable.  This is required to fully support virtio-mem on arm64,
making also kexec_file behave like on x86-64.

This patch (of 2):

If memblock_add_node() fails, we're most probably running out of memory.
While this is unlikely to happen, it can happen and having memory added
without a memblock can be problematic for architectures that use
memblock to detect valid memory.  Let's fail in a nice way instead of
silently ignoring the error.

Link: https://lkml.kernel.org/r/20211004093605.5830-1-david@redhat.com
Link: https://lkml.kernel.org/r/20211004093605.5830-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Jianyong Wu <Jianyong.Wu@arm.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Shahab Vahedi <shahab@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:42 -07:00
David Hildenbrand
6b740c6c3a mm/memory_hotplug: remove HIGHMEM leftovers
We don't support CONFIG_MEMORY_HOTPLUG on 32 bit and consequently not
HIGHMEM.  Let's remove any leftover code -- including the unused
"status_change_nid_high" field part of the memory notifier.

Link: https://lkml.kernel.org/r/20210929143600.49379-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Alex Shi <alexs@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:42 -07:00
David Hildenbrand
7ec58a2b94 mm/memory_hotplug: restrict CONFIG_MEMORY_HOTPLUG to 64 bit
32 bit support is broken in various ways: for example, we can online
memory that should actually go to ZONE_HIGHMEM to ZONE_MOVABLE or in
some cases even to one of the other kernel zones.

We marked it BROKEN in commit b59d02ed08 ("mm/memory_hotplug: disable
the functionality for 32b") almost one year ago.  According to that
commit it might be broken at least since 2017.  Further, there is hardly
a sane use case nowadays.

Let's just depend completely on 64bit, dropping the "BROKEN" dependency
to make clear that we are not going to support it again.  Next, we'll
remove some HIGHMEM leftovers from memory hotplug code to clean up.

Link: https://lkml.kernel.org/r/20210929143600.49379-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Alex Shi <alexs@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:42 -07:00
David Hildenbrand
50f9481ed9 mm/memory_hotplug: remove CONFIG_MEMORY_HOTPLUG_SPARSE
CONFIG_MEMORY_HOTPLUG depends on CONFIG_SPARSEMEM, so there is no need for
CONFIG_MEMORY_HOTPLUG_SPARSE anymore; adjust all instances to use
CONFIG_MEMORY_HOTPLUG and remove CONFIG_MEMORY_HOTPLUG_SPARSE.

Link: https://lkml.kernel.org/r/20210929143600.49379-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>	[kselftest]
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Oscar Salvador <osalvador@suse.de>
Cc: Alex Shi <alexs@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:42 -07:00
David Hildenbrand
71b6f2dda8 mm/memory_hotplug: remove CONFIG_X86_64_ACPI_NUMA dependency from CONFIG_MEMORY_HOTPLUG
Patch series "mm/memory_hotplug: Kconfig and 32 bit cleanups".

Some cleanups around CONFIG_MEMORY_HOTPLUG, including removing 32 bit
leftovers of memory hotplug support.

This patch (of 6):

SPARSEMEM is the only possible memory model for x86-64, FLATMEM is not
possible:

	config ARCH_FLATMEM_ENABLE
		def_bool y
		depends on X86_32 && !NUMA

And X86_64_ACPI_NUMA (obviously) only supports x86-64:

	config X86_64_ACPI_NUMA
		def_bool y
		depends on X86_64 && NUMA && ACPI && PCI

Let's just remove the CONFIG_X86_64_ACPI_NUMA dependency, as it does no
longer make sense.

Link: https://lkml.kernel.org/r/20210929143600.49379-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Alex Shi <alexs@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:42 -07:00
Tang Yizhou
ac62554ba7 mm/memory_hotplug: add static qualifier for online_policy_to_str()
online_policy_to_str is only used in memory_hotplug.c and should be
defined as static.

Link: https://lkml.kernel.org/r/20210913024534.26161-1-tangyizhou@huawei.com
Signed-off-by: Tang Yizhou <tangyizhou@huawei.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:42 -07:00
Lin Feng
a997058679 mm: vmstat.c: make extfrag_index show more pretty
fragmentation_index may return -1000 and the corresponding formated
value showed by seq_printf will take a negative signatrue, but other
positive formated values don't take a positive signatrue, so the output
becomes unaligned.

before:
  Node 0, zone      DMA -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000
  Node 0, zone    DMA32 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000
  Node 0, zone   Normal -1.000 -1.000 -1.000 -1.000 0.931 0.966 0.983 0.992 0.996 0.998 0.999

after this patch:
  Node 0, zone      DMA -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000
  Node 0, zone    DMA32 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000
  Node 0, zone   Normal -1.000 -1.000 -1.000 -1.000  0.931  0.966  0.983  0.992  0.996  0.998  0.999

Link: https://lkml.kernel.org/r/20211019103241.134797-1-linf@wangsu.com
Signed-off-by: Lin Feng <linf@wangsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:42 -07:00
Liu Shixin
af1c31acc8 mm/vmstat: annotate data race for zone->free_area[order].nr_free
KCSAN reports a data-race on v5.10 which also exists on mainline:

  BUG: KCSAN: data-race in extfrag_for_order+0x33/0x2d0

  race at unknown origin, with read to 0xffff9ee9bfffab48 of 8 bytes by task 34 on cpu 1:
   extfrag_for_order+0x33/0x2d0
   kcompactd+0x5f0/0xce0
   kthread+0x1f9/0x220
   ret_from_fork+0x22/0x30

  Reported by Kernel Concurrency Sanitizer on:
  CPU: 1 PID: 34 Comm: kcompactd0 Not tainted 5.10.0+ #2
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014

Access to zone->free_area[order].nr_free in extfrag_for_order() and
frag_show_print() is lockless.  That's intentional and the stats are a
rough estimate anyway.  Annotate them with data_race().

[liushixin2@huawei.com: add comments]
  Link: https://lkml.kernel.org/r/20210918084655.2696522-1-liushixin2@huawei.com

Link: https://lkml.kernel.org/r/20210908015606.3999871-1-liushixin2@huawei.com
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:41 -07:00
Kefeng Wang
916caa127c mm: nommu: kill arch_get_unmapped_area()
When nommu, the arch_get_unmapped_area() will not be called, just kill
it.

Link: https://lkml.kernel.org/r/20210910061906.36299-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:41 -07:00
Lin Feng
fb25a77dde mm/readahead.c: fix incorrect comments for get_init_ra_size
In fact, formated values returned by get_init_ra_size are not that
intuitive.  This patch make the comments reflect its truth.

Link: https://lkml.kernel.org/r/20211019104812.135602-1-linf@wangsu.com
Signed-off-by: Lin Feng <linf@wangsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:41 -07:00
Yang Shi
20f9ba4f99 mm: migrate: make demotion knob depend on migration
The memory demotion needs to call migrate_pages() to do the jobs.  And
it is controlled by a knob, however, the knob doesn't depend on
CONFIG_MIGRATION.  The knob could be truned on even though MIGRATION is
disabled, this will not cause any crash since migrate_pages() would just
return -ENOSYS.  But it is definitely not optimal to go through demotion
path then retry regular swap every time.

And it doesn't make too much sense to have the knob visible to the users
when !MIGRATION.  Move the related code from mempolicy.[h|c] to
migrate.[h|c].

Link: https://lkml.kernel.org/r/20211015005559.246709-1-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Acked-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:41 -07:00
John Hubbard
8eb42beac8 mm/migrate: de-duplicate migrate_reason strings
In order to remove the need to manually keep three different files in
synch, provide a common definition of the mapping between enum
migrate_reason, and the associated strings for each enum item.

1. Use the tracing system's mapping of enums to strings, by redefining
   and reusing the MIGRATE_REASON and supporting macros, and using that
   to populate the string array in mm/debug.c.

2. Move enum migrate_reason to migrate_mode.h. This is not strictly
   necessary for this patch, but migrate mode and migrate reason go
   together, so this will slightly clarify things.

Link: https://lkml.kernel.org/r/20210922041755.141817-2-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Weizhao Ouyang <o451686892@gmail.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:41 -07:00
Zhenguo Yao
b5389086ad hugetlbfs: extend the definition of hugepages parameter to support node allocation
We can specify the number of hugepages to allocate at boot.  But the
hugepages is balanced in all nodes at present.  In some scenarios, we
only need hugepages in one node.  For example: DPDK needs hugepages
which are in the same node as NIC.

If DPDK needs four hugepages of 1G size in node1 and system has 16 numa
nodes we must reserve 64 hugepages on the kernel cmdline.  But only four
hugepages are used.  The others should be free after boot.  If the
system memory is low(for example: 64G), it will be an impossible task.

So extend the hugepages parameter to support specifying hugepages on a
specific node.  For example add following parameter:

  hugepagesz=1G hugepages=0:1,1:3

It will allocate 1 hugepage in node0 and 3 hugepages in node1.

Link: https://lkml.kernel.org/r/20211005054729.86457-1-yaozhenguo1@gmail.com
Signed-off-by: Zhenguo Yao <yaozhenguo1@gmail.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Zhenguo Yao <yaozhenguo1@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:41 -07:00
Sultan Alsawaf
3723929eb0 mm: mark the OOM reaper thread as freezable
The OOM reaper alters user address space which might theoretically alter
the snapshot if reaping is allowed to happen after the freezer quiescent
state.  To this end, the reaper kthread uses wait_event_freezable()
while waiting for any work so that it cannot run while the system
freezes.

However, the current implementation doesn't respect the freezer because
all kernel threads are created with the PF_NOFREEZE flag, so they are
automatically excluded from freezing operations.  This means that the
OOM reaper can race with system snapshotting if it has work to do while
the system is being frozen.

Fix this by adding a set_freezable() call which will clear the
PF_NOFREEZE flag and thus make the OOM reaper visible to the freezer.

Please note that the OOM reaper altering the snapshot this way is mostly
a theoretical concern and has not been observed in practice.

Link: https://lkml.kernel.org/r/20210921165758.6154-1-sultan@kerneltoast.com
Link: https://lkml.kernel.org/r/20210918233920.9174-1-sultan@kerneltoast.com
Fixes: aac4536355 ("mm, oom: introduce oom reaper")
Signed-off-by: Sultan Alsawaf <sultan@kerneltoast.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:41 -07:00
Mike Rapoport
4421cca0a3 memblock: use memblock_free for freeing virtual pointers
Rename memblock_free_ptr() to memblock_free() and use memblock_free()
when freeing a virtual pointer so that memblock_free() will be a
counterpart of memblock_alloc()

The callers are updated with the below semantic patch and manual
addition of (void *) casting to pointers that are represented by
unsigned long variables.

    @@
    identifier vaddr;
    expression size;
    @@
    (
    - memblock_phys_free(__pa(vaddr), size);
    + memblock_free(vaddr, size);
    |
    - memblock_free_ptr(vaddr, size);
    + memblock_free(vaddr, size);
    )

[sfr@canb.auug.org.au: fixup]
  Link: https://lkml.kernel.org/r/20211018192940.3d1d532f@canb.auug.org.au

Link: https://lkml.kernel.org/r/20210930185031.18648-7-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Juergen Gross <jgross@suse.com>
Cc: Shahab Vahedi <Shahab.Vahedi@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:41 -07:00
Mike Rapoport
3ecc68349b memblock: rename memblock_free to memblock_phys_free
Since memblock_free() operates on a physical range, make its name
reflect it and rename it to memblock_phys_free(), so it will be a
logical counterpart to memblock_phys_alloc().

The callers are updated with the below semantic patch:

    @@
    expression addr;
    expression size;
    @@
    - memblock_free(addr, size);
    + memblock_phys_free(addr, size);

Link: https://lkml.kernel.org/r/20210930185031.18648-6-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Juergen Gross <jgross@suse.com>
Cc: Shahab Vahedi <Shahab.Vahedi@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:41 -07:00
Mike Rapoport
621d973901 memblock: stop aliasing __memblock_free_late with memblock_free_late
memblock_free_late() is a NOP wrapper for __memblock_free_late(), there
is no point to keep this indirection.

Drop the wrapper and rename __memblock_free_late() to
memblock_free_late().

Link: https://lkml.kernel.org/r/20210930185031.18648-5-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Juergen Gross <jgross@suse.com>
Cc: Shahab Vahedi <Shahab.Vahedi@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:41 -07:00
Mike Rapoport
fa27717110 memblock: drop memblock_free_early_nid() and memblock_free_early()
memblock_free_early_nid() is unused and memblock_free_early() is an
alias for memblock_free().

Replace calls to memblock_free_early() with calls to memblock_free() and
remove memblock_free_early() and memblock_free_early_nid().

Link: https://lkml.kernel.org/r/20210930185031.18648-4-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Juergen Gross <jgross@suse.com>
Cc: Shahab Vahedi <Shahab.Vahedi@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:41 -07:00
Yuanzheng Song
7e6ec49c18 mm/vmpressure: fix data-race with memcg->socket_pressure
When reading memcg->socket_pressure in mem_cgroup_under_socket_pressure()
and writing memcg->socket_pressure in vmpressure() at the same time, the
following data-race occurs:

  BUG: KCSAN: data-race in __sk_mem_reduce_allocated / vmpressure

  write to 0xffff8881286f4938 of 8 bytes by task 24550 on cpu 3:
   vmpressure+0x218/0x230 mm/vmpressure.c:307
   shrink_node_memcgs+0x2b9/0x410 mm/vmscan.c:2658
   shrink_node+0x9d2/0x11d0 mm/vmscan.c:2769
   shrink_zones+0x29f/0x470 mm/vmscan.c:2972
   do_try_to_free_pages+0x193/0x6e0 mm/vmscan.c:3027
   try_to_free_mem_cgroup_pages+0x1c0/0x3f0 mm/vmscan.c:3345
   reclaim_high mm/memcontrol.c:2440 [inline]
   mem_cgroup_handle_over_high+0x18b/0x4d0 mm/memcontrol.c:2624
   tracehook_notify_resume include/linux/tracehook.h:197 [inline]
   exit_to_user_mode_loop kernel/entry/common.c:164 [inline]
   exit_to_user_mode_prepare+0x110/0x170 kernel/entry/common.c:191
   syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:266
   ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:289

  read to 0xffff8881286f4938 of 8 bytes by interrupt on cpu 1:
   mem_cgroup_under_socket_pressure include/linux/memcontrol.h:1483 [inline]
   sk_under_memory_pressure include/net/sock.h:1314 [inline]
   __sk_mem_reduce_allocated+0x1d2/0x270 net/core/sock.c:2696
   __sk_mem_reclaim+0x44/0x50 net/core/sock.c:2711
   sk_mem_reclaim include/net/sock.h:1490 [inline]
   ......
   net_rx_action+0x17a/0x480 net/core/dev.c:6864
   __do_softirq+0x12c/0x2af kernel/softirq.c:298
   run_ksoftirqd+0x13/0x20 kernel/softirq.c:653
   smpboot_thread_fn+0x33f/0x510 kernel/smpboot.c:165
   kthread+0x1fc/0x220 kernel/kthread.c:292
   ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Fix it by using READ_ONCE() and WRITE_ONCE() to read and write
memcg->socket_pressure.

Link: https://lkml.kernel.org/r/20211025082843.671690-1-songyuanzheng@huawei.com
Signed-off-by: Yuanzheng Song <songyuanzheng@huawei.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Alex Shi <alexs@kernel.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:40 -07:00
Mel Gorman
66ce520bb7 mm/vmscan: delay waking of tasks throttled on NOPROGRESS
Tracing indicates that tasks throttled on NOPROGRESS are woken
prematurely resulting in occasional massive spikes in direct reclaim
activity.  This patch wakes tasks throttled on NOPROGRESS if reclaim
efficiency is at least 12%.

Link: https://lkml.kernel.org/r/20211022144651.19914-9-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: "Darrick J . Wong" <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Rik van Riel <riel@surriel.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:40 -07:00
Mel Gorman
a19594ca4a mm/vmscan: increase the timeout if page reclaim is not making progress
Tracing of the stutterp workload showed the following delays

      1 usect_delayed=124000 reason=VMSCAN_THROTTLE_NOPROGRESS
      1 usect_delayed=128000 reason=VMSCAN_THROTTLE_NOPROGRESS
      1 usect_delayed=176000 reason=VMSCAN_THROTTLE_NOPROGRESS
      1 usect_delayed=536000 reason=VMSCAN_THROTTLE_NOPROGRESS
      1 usect_delayed=544000 reason=VMSCAN_THROTTLE_NOPROGRESS
      1 usect_delayed=556000 reason=VMSCAN_THROTTLE_NOPROGRESS
      1 usect_delayed=624000 reason=VMSCAN_THROTTLE_NOPROGRESS
      1 usect_delayed=716000 reason=VMSCAN_THROTTLE_NOPROGRESS
      1 usect_delayed=772000 reason=VMSCAN_THROTTLE_NOPROGRESS
      2 usect_delayed=512000 reason=VMSCAN_THROTTLE_NOPROGRESS
     16 usect_delayed=120000 reason=VMSCAN_THROTTLE_NOPROGRESS
     53 usect_delayed=116000 reason=VMSCAN_THROTTLE_NOPROGRESS
    116 usect_delayed=112000 reason=VMSCAN_THROTTLE_NOPROGRESS
   5907 usect_delayed=108000 reason=VMSCAN_THROTTLE_NOPROGRESS
  71741 usect_delayed=104000 reason=VMSCAN_THROTTLE_NOPROGRESS

All the throttling hit the full timeout and then there was wakeup delays
meaning that the wakeups are premature as no other reclaimer such as
kswapd has made progress.  This patch increases the maximum timeout.

Link: https://lkml.kernel.org/r/20211022144651.19914-8-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: "Darrick J . Wong" <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Rik van Riel <riel@surriel.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:40 -07:00
Mel Gorman
c3f4a9a2b0 mm/vmscan: centralise timeout values for reclaim_throttle
Neil Brown raised concerns about callers of reclaim_throttle specifying
a timeout value.  The original timeout values to congestion_wait() were
probably pulled out of thin air or copy&pasted from somewhere else.
This patch centralises the timeout values and selects a timeout based on
the reason for reclaim throttling.  These figures are also pulled out of
the same thin air but better values may be derived

Running a workload that is throttling for inappropriate periods and
tracing mm_vmscan_throttled can be used to pick a more appropriate
value.  Excessive throttling would pick a lower timeout where as
excessive CPU usage in reclaim context would select a larger timeout.
Ideally a large value would always be used and the wakeups would occur
before a timeout but that requires careful testing.

Link: https://lkml.kernel.org/r/20211022144651.19914-7-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: "Darrick J . Wong" <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Rik van Riel <riel@surriel.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:40 -07:00