Commit Graph

994573 Commits

Author SHA1 Message Date
Charan Teja Reddy
40d7e20320 mm/compaction: correct deferral logic for proactive compaction
should_proactive_compact_node() returns true when sum of the weighted
fragmentation score of all the zones in the node is greater than the
wmark_high of compaction, which then triggers the proactive compaction
that operates on the individual zones of the node.  But proactive
compaction runs on the zone only when its weighted fragmentation score
is greater than wmark_low(=wmark_high - 10).

This means that the sum of the weighted fragmentation scores of all the
zones can exceed the wmark_high but individual weighted fragmentation zone
scores can still be less than wmark_low which makes the unnecessary
trigger of the proactive compaction only to return doing nothing.

Issue with the return of proactive compaction with out even trying is its
deferral.  It is simply deferred for 1 << COMPACT_MAX_DEFER_SHIFT if the
scores across the proactive compaction is same, thinking that compaction
didn't make any progress but in reality it didn't even try.  With the
delay between successive retries for proactive compaction is 500msec, it
can result into the deferral for ~30sec with out even trying the proactive
compaction.

Test scenario is that: compaction_proactiveness=50 thus the wmark_low = 50
and wmark_high = 60.  System have 2 zones(Normal and Movable) with sizes
5GB and 6GB respectively.  After opening some apps on the android, the
weighted fragmentation scores of these zones are 47 and 49 respectively.
Since the sum of these fragmentation scores are above the wmark_high which
triggers the proactive compaction and there since the individual zones
weighted fragmentation scores are below wmark_low, it returns without
trying the proactive compaction.  As a result the weighted fragmentation
scores of the zones are still 47 and 49 which makes the existing logic to
defer the compaction thinking that noprogress is made across the
compaction.

Fix this by checking just zone fragmentation score, not the weighted, in
__compact_finished() and use the zones weighted fragmentation score in
fragmentation_score_node().  In the test case above, If the weighted
average of is above wmark_high, then individual score (not adjusted) of
atleast one zone has to be above wmark_high.  Thus it avoids the
unnecessary trigger and deferrals of the proactive compaction.

Link: https://lkml.kernel.org/r/1610989938-31374-1-git-send-email-charante@codeaurora.org
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nitin Gupta <ngupta@nitingupta.dev>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:34 -08:00
Miaohe Lin
e2d26aa5fb mm/compaction: remove duplicated VM_BUG_ON_PAGE !PageLocked
The VM_BUG_ON_PAGE(!PageLocked(page), page) is also done in PageMovable.
Remove this explicitly one.

Link: https://lkml.kernel.org/r/20210109081420.46030-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.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>
2021-02-24 13:38:34 -08:00
Alex Shi
d99fd5feb0 mm/compaction: remove rcu_read_lock during page compaction
isolate_migratepages_block() used rcu_read_lock() with the intention of
safeguarding against the mem_cgroup being destroyed concurrently; but
its TestClearPageLRU already protects against that.  Delete the
unnecessary rcu_read_lock() and _unlock().

Hugh Dickins helped on commit log polishing, Thanks!

Link: https://lkml.kernel.org/r/1608614453-10739-3-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:34 -08:00
Miaohe Lin
c457cd96f1 z3fold: simplify the zhdr initialization code in init_z3fold_page()
We can simplify the zhdr initialization by memset() the zhdr first
instead of set struct member to zero one by one.  This would also make
code more compact and clear.

Link: https://lkml.kernel.org/r/20210120085851.16159-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:34 -08:00
Miaohe Lin
70ad3196a6 z3fold: remove unused attribute for release_z3fold_page
Since commit dcf5aedb24 ("z3fold: stricter locking and more careful
reclaim"), release_z3fold_page() is used again.  So we can drop the
unused attribute safely.

Link: https://lkml.kernel.org/r/20210120084008.58432-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:34 -08:00
Dave Hansen
519983645a mm/vmscan: restore zone_reclaim_mode ABI
I went to go add a new RECLAIM_* mode for the zone_reclaim_mode sysctl.
Like a good kernel developer, I also went to go update the
documentation.  I noticed that the bits in the documentation didn't
match the bits in the #defines.

The VM never explicitly checks the RECLAIM_ZONE bit.  The bit is,
however implicitly checked when checking 'node_reclaim_mode==0'.  The
RECLAIM_ZONE #define was removed in a cleanup.  That, by itself is fine.

But, when the bit was removed (bit 0) the _other_ bit locations also got
changed.  That's not OK because the bit values are documented to mean
one specific thing.  Users surely do not expect the meaning to change
from kernel to kernel.

The end result is that if someone had a script that did:

	sysctl vm.zone_reclaim_mode=1

it would have gone from enabling node reclaim for clean unmapped pages
to writing out pages during node reclaim after the commit in question.
That's not great.

Put the bits back the way they were and add a comment so something like
this is a bit harder to do again.  Update the documentation to make it
clear that the first bit is ignored.

Link: https://lkml.kernel.org/r/20210219172555.FF0CDF23@viggo.jf.intel.com
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Fixes: 648b5cf368 ("mm/vmscan: remove unused RECLAIM_OFF/RECLAIM_ZONE")
Reviewed-by: Ben Widawsky <ben.widawsky@intel.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Daniel Wagner <dwagner@suse.de>
Cc: "Tobin C. Harding" <tobin@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Qian Cai <cai@lca.pw>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:34 -08:00
Mike Kravetz
ff54611762 hugetlb: fix uninitialized subpool pointer
Gerald Schaefer reported a panic on s390 in hugepage_subpool_put_pages()
with linux-next 5.12.0-20210222.
Call trace:
  hugepage_subpool_put_pages.part.0+0x2c/0x138
  __free_huge_page+0xce/0x310
  alloc_pool_huge_page+0x102/0x120
  set_max_huge_pages+0x13e/0x350
  hugetlb_sysctl_handler_common+0xd8/0x110
  hugetlb_sysctl_handler+0x48/0x58
  proc_sys_call_handler+0x138/0x238
  new_sync_write+0x10e/0x198
  vfs_write.part.0+0x12c/0x238
  ksys_write+0x68/0xf8
  do_syscall+0x82/0xd0
  __do_syscall+0xb4/0xc8
  system_call+0x72/0x98

This is a result of the change which moved the hugetlb page subpool
pointer from page->private to page[1]->private.  When new pages are
allocated from the buddy allocator, the private field of the head
page will be cleared, but the private field of subpages is not modified.
Therefore, old values may remain.

Fix by initializing hugetlb page subpool pointer in prep_new_huge_page().

Link: https://lkml.kernel.org/r/20210223215544.313871-1-mike.kravetz@oracle.com
Fixes: f1280272ae4d ("hugetlb: use page.private for hugetlb specific page flags")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:34 -08:00
Mike Kravetz
d95c033777 include/linux/hugetlb.h: add synchronization information for new hugetlb specific flags
Add comments, no functional change.

Link: https://lkml.kernel.org/r/62a80585-2a73-10cc-4a2d-5721540d4ad2@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:34 -08:00
Mike Kravetz
6c03714901 hugetlb: convert PageHugeFreed to HPageFreed flag
Use new hugetlb specific HPageFreed flag to replace the PageHugeFreed
interfaces.

Link: https://lkml.kernel.org/r/20210122195231.324857-6-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:34 -08:00
Mike Kravetz
9157c31186 hugetlb: convert PageHugeTemporary() to HPageTemporary flag
Use new hugetlb specific HPageTemporary flag to replace the
PageHugeTemporary() interfaces.  PageHugeTemporary does contain a
PageHuge() check.  However, this interface is only used within hugetlb
code where we know we are dealing with a hugetlb page.  Therefore, the
check can be eliminated.

Link: https://lkml.kernel.org/r/20210122195231.324857-5-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:34 -08:00
Mike Kravetz
8f251a3d5c hugetlb: convert page_huge_active() HPageMigratable flag
Use the new hugetlb page specific flag HPageMigratable to replace the
page_huge_active interfaces.  By it's name, page_huge_active implied that
a huge page was on the active list.  However, that is not really what code
checking the flag wanted to know.  It really wanted to determine if the
huge page could be migrated.  This happens when the page is actually added
to the page cache and/or task page table.  This is the reasoning behind
the name change.

The VM_BUG_ON_PAGE() calls in the *_huge_active() interfaces are not
really necessary as we KNOW the page is a hugetlb page.  Therefore, they
are removed.

The routine page_huge_active checked for PageHeadHuge before testing the
active bit.  This is unnecessary in the case where we hold a reference or
lock and know it is a hugetlb head page.  page_huge_active is also called
without holding a reference or lock (scan_movable_pages), and can race
with code freeing the page.  The extra check in page_huge_active shortened
the race window, but did not prevent the race.  Offline code calling
scan_movable_pages already deals with these races, so removing the check
is acceptable.  Add comment to racy code.

[songmuchun@bytedance.com: remove set_page_huge_active() declaration from include/linux/hugetlb.h]
  Link: https://lkml.kernel.org/r/CAMZfGtUda+KoAZscU0718TN61cSFwp4zy=y2oZ=+6Z2TAZZwng@mail.gmail.com

Link: https://lkml.kernel.org/r/20210122195231.324857-3-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:34 -08:00
Mike Kravetz
d6995da311 hugetlb: use page.private for hugetlb specific page flags
Patch series "create hugetlb flags to consolidate state", v3.

While discussing a series of hugetlb fixes in [1], it became evident that
the hugetlb specific page state information is stored in a somewhat
haphazard manner.  Code dealing with state information would be easier to
read, understand and maintain if this information was stored in a
consistent manner.

This series uses page.private of the hugetlb head page for storing a set
of hugetlb specific page flags.  Routines are priovided for test, set and
clear of the flags.

[1] https://lore.kernel.org/r/20210106084739.63318-1-songmuchun@bytedance.com

This patch (of 4):

As hugetlbfs evolved, state information about hugetlb pages was added.
One 'convenient' way of doing this was to use available fields in tail
pages.  Over time, it has become difficult to know the meaning or contents
of fields simply by looking at a small bit of code.  Sometimes, the naming
is just confusing.  For example: The PagePrivate flag indicates a huge
page reservation was consumed and needs to be restored if an error is
encountered and the page is freed before it is instantiated.  The
page.private field contains the pointer to a subpool if the page is
associated with one.

In an effort to make the code more readable, use page.private to contain
hugetlb specific page flags.  These flags will have test, set and clear
functions similar to those used for 'normal' page flags.  More
importantly, an enum of flag values will be created with names that
actually reflect their purpose.

In this patch,
- Create infrastructure for hugetlb specific page flag functions
- Move subpool pointer to page[1].private to make way for flags
  Create routines with meaningful names to modify subpool field
- Use new HPageRestoreReserve flag instead of PagePrivate

Conversion of other state information will happen in subsequent patches.

Link: https://lkml.kernel.org/r/20210122195231.324857-1-mike.kravetz@oracle.com
Link: https://lkml.kernel.org/r/20210122195231.324857-2-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:34 -08:00
Oscar Salvador
aeddcee6c1 mm: workingset: clarify eviction order and distance calculation
The premise of the refault distance is that it can be seen as a deficit of
the inactive list space, so that if the inactive list would have had (R -
E) more slots, the page would not have been evicted but promoted to the
active list instead.

However, the way the code is ordered right now set us to be off by one, so
the real number of slots would be (R - E) + 1.  I stumbled upon this when
trying to understand the code and it puzzled me that the comments did not
match what the code did.

This it not an issue at all since evictions and refaults tend to happen in
a number large enough that being off-by-one does not have any impact - and
since the compiler and CPUs are free to rearrange the execution sequence
anyway.

But as Johannes says, it is better to re-arrange the code in the proper
order since otherwise would be misleading to somebody who is actively
reading and trying to understand the logic of the code - like it happened
to me.

Link: https://lkml.kernel.org/r/20210201060651.3781-1-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:34 -08:00
Yu Zhao
2091339d59 mm/vmscan.c: make lruvec_lru_size() static
All other references to the function were removed after
commit b910718a94 ("mm: vmscan: detect file thrashing at the reclaim
root").

Link: https://lore.kernel.org/linux-mm/20201207220949.830352-11-yuzhao@google.com/
Link: https://lkml.kernel.org/r/20210122220600.906146-11-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.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>
2021-02-24 13:38:34 -08:00
Yu Zhao
289ccba18a include/linux/mm_inline.h: fold __update_lru_size() into its sole caller
All other references to the function were removed after commit
a892cb6b97 ("mm/vmscan.c: use update_lru_size() in update_lru_sizes()").

Link: https://lore.kernel.org/linux-mm/20201207220949.830352-10-yuzhao@google.com/
Link: https://lkml.kernel.org/r/20210122220600.906146-10-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.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>
2021-02-24 13:38:33 -08:00
Yu Zhao
c1770e34f3 include/linux/mm_inline.h: fold page_lru_base_type() into its sole caller
We've removed all other references to this function.

Link: https://lore.kernel.org/linux-mm/20201207220949.830352-9-yuzhao@google.com/
Link: https://lkml.kernel.org/r/20210122220600.906146-9-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.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>
2021-02-24 13:38:33 -08:00
Yu Zhao
bc7112719e mm: VM_BUG_ON lru page flags
Move scattered VM_BUG_ONs to two essential places that cover all
lru list additions and deletions.

Link: https://lore.kernel.org/linux-mm/20201207220949.830352-8-yuzhao@google.com/
Link: https://lkml.kernel.org/r/20210122220600.906146-8-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.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>
2021-02-24 13:38:33 -08:00
Yu Zhao
8756017962 mm: add __clear_page_lru_flags() to replace page_off_lru()
Similar to page_off_lru(), the new function does non-atomic clearing
of PageLRU() in addition to PageActive() and PageUnevictable(), on a
page that has no references left.

If PageActive() and PageUnevictable() are both set, refuse to clear
either and leave them to bad_page(). This is a behavior change that
is meant to help debug.

Link: https://lore.kernel.org/linux-mm/20201207220949.830352-7-yuzhao@google.com/
Link: https://lkml.kernel.org/r/20210122220600.906146-7-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.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>
2021-02-24 13:38:33 -08:00
Yu Zhao
46ae6b2cc2 mm/swap.c: don't pass "enum lru_list" to del_page_from_lru_list()
The parameter is redundant in the sense that it can be potentially
extracted from the "struct page" parameter by page_lru(). We need to
make sure that existing PageActive() or PageUnevictable() remains
until the function returns. A few places don't conform, and simple
reordering fixes them.

This patch may have left page_off_lru() seemingly odd, and we'll take
care of it in the next patch.

Link: https://lore.kernel.org/linux-mm/20201207220949.830352-6-yuzhao@google.com/
Link: https://lkml.kernel.org/r/20210122220600.906146-6-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.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>
2021-02-24 13:38:33 -08:00
Yu Zhao
861404536a mm/swap.c: don't pass "enum lru_list" to trace_mm_lru_insertion()
The parameter is redundant in the sense that it can be extracted
from the "struct page" parameter by page_lru() correctly.

Link: https://lore.kernel.org/linux-mm/20201207220949.830352-5-yuzhao@google.com/
Link: https://lkml.kernel.org/r/20210122220600.906146-5-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.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>
2021-02-24 13:38:33 -08:00
Yu Zhao
3a9c9788a3 mm: don't pass "enum lru_list" to lru list addition functions
The "enum lru_list" parameter to add_page_to_lru_list() and
add_page_to_lru_list_tail() is redundant in the sense that it can
be extracted from the "struct page" parameter by page_lru().

A caveat is that we need to make sure PageActive() or
PageUnevictable() is correctly set or cleared before calling
these two functions. And they are indeed.

Link: https://lore.kernel.org/linux-mm/20201207220949.830352-4-yuzhao@google.com/
Link: https://lkml.kernel.org/r/20210122220600.906146-4-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.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>
2021-02-24 13:38:33 -08:00
Yu Zhao
f90d8191ac include/linux/mm_inline.h: shuffle lru list addition and deletion functions
These functions will call page_lru() in the following patches.  Move them
below page_lru() to avoid the forward declaration.

Link: https://lore.kernel.org/linux-mm/20201207220949.830352-3-yuzhao@google.com/
Link: https://lkml.kernel.org/r/20210122220600.906146-3-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
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>
2021-02-24 13:38:33 -08:00
Yu Zhao
42895ea73b mm/vmscan.c: use add_page_to_lru_list()
Patch series "mm: lru related cleanups", v2.

The cleanups are intended to reduce the verbosity in lru list operations
and make them less error-prone.  A typical example would be how the
patches change __activate_page():

 static void __activate_page(struct page *page, struct lruvec *lruvec)
 {
 	if (!PageActive(page) && !PageUnevictable(page)) {
-		int lru = page_lru_base_type(page);
 		int nr_pages = thp_nr_pages(page);

-		del_page_from_lru_list(page, lruvec, lru);
+		del_page_from_lru_list(page, lruvec);
 		SetPageActive(page);
-		lru += LRU_ACTIVE;
-		add_page_to_lru_list(page, lruvec, lru);
+		add_page_to_lru_list(page, lruvec);
 		trace_mm_lru_activate(page);

There are a few more places like __activate_page() and they are
unnecessarily repetitive in terms of figuring out which list a page should
be added onto or deleted from.  And with the duplicated code removed, they
are easier to read, IMO.

Patch 1 to 5 basically cover the above.  Patch 6 and 7 make code more
robust by improving bug reporting.  Patch 8, 9 and 10 take care of some
dangling helpers left in header files.

This patch (of 10):

There is add_page_to_lru_list(), and move_pages_to_lru() should reuse it,
not duplicate it.

Link: https://lkml.kernel.org/r/20210122220600.906146-1-yuzhao@google.com
Link: https://lore.kernel.org/linux-mm/20201207220949.830352-2-yuzhao@google.com/
Link: https://lkml.kernel.org/r/20210122220600.906146-2-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:33 -08:00
Miaohe Lin
725cac1c7e mm/workingset.c: avoid unnecessary max_nodes estimation in count_shadow_nodes()
If list_lru_shrink_count is 0, we always return SHRINK_EMPTY regardless of
the value of max_nodes.  So we can return early if nodes == 0 to save some
cpu cycles of approximating a reasonable limit for the nodes.

Link: https://lkml.kernel.org/r/20210123073825.46709-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:33 -08:00
Alex Shi
c2135f7c57 mm/vmscan: __isolate_lru_page_prepare() cleanup
The function just returns 2 results, so using a 'switch' to deal with its
result is unnecessary.  Also simplify it to a bool func as Vlastimil
suggested.

Also remove 'goto' by reusing list_move(), and take Matthew Wilcox's
suggestion to update comments in function.

Link: https://lkml.kernel.org/r/728874d7-2d93-4049-68c1-dcc3b2d52ccd@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:33 -08:00
Chen Wandun
7ecc956551 mm/hugetlb: suppress wrong warning info when alloc gigantic page
If hugetlb_cma is enabled, it will skip boot time allocation when
allocating gigantic page, that doesn't means allocation failure, so
suppress this warning info.

Link: https://lkml.kernel.org/r/20210219123909.13130-1-chenwandun@huawei.com
Fixes: cf11e85fc0 ("mm: hugetlb: optionally allocate gigantic hugepages using cma")
Signed-off-by: Chen Wandun <chenwandun@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:33 -08:00
Mike Kravetz
3272cfc252 hugetlb: fix copy_huge_page_from_user contig page struct assumption
page structs are not guaranteed to be contiguous for gigantic pages.  The
routine copy_huge_page_from_user can encounter gigantic pages, yet it
assumes page structs are contiguous when copying pages from user space.

Since page structs for the target gigantic page are not contiguous, the
data copied from user space could overwrite other pages not associated
with the gigantic page and cause data corruption.

Non-contiguous page structs are generally not an issue.  However, they can
exist with a specific kernel configuration and hotplug operations.  For
example: Configure the kernel with CONFIG_SPARSEMEM and
!CONFIG_SPARSEMEM_VMEMMAP.  Then, hotplug add memory for the area where
the gigantic page will be allocated.

Link: https://lkml.kernel.org/r/20210217184926.33567-2-mike.kravetz@oracle.com
Fixes: 8fb5debc5f ("userfaultfd: hugetlbfs: add hugetlb_mcopy_atomic_pte for userfaultfd support")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:33 -08:00
Mike Kravetz
dbfee5aee7 hugetlb: fix update_and_free_page contig page struct assumption
page structs are not guaranteed to be contiguous for gigantic pages.  The
routine update_and_free_page can encounter a gigantic page, yet it assumes
page structs are contiguous when setting page flags in subpages.

If update_and_free_page encounters non-contiguous page structs, we can see
“BUG: Bad page state in process …” errors.

Non-contiguous page structs are generally not an issue.  However, they can
exist with a specific kernel configuration and hotplug operations.  For
example: Configure the kernel with CONFIG_SPARSEMEM and
!CONFIG_SPARSEMEM_VMEMMAP.  Then, hotplug add memory for the area where
the gigantic page will be allocated.  Zi Yan outlined steps to reproduce
here [1].

[1] https://lore.kernel.org/linux-mm/16F7C58B-4D79-41C5-9B64-A1A1628F4AF2@nvidia.com/

Link: https://lkml.kernel.org/r/20210217184926.33567-1-mike.kravetz@oracle.com
Fixes: 944d9fec8d ("hugetlb: add support for gigantic page allocation at runtime")
Signed-off-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:33 -08:00
Miaohe Lin
aca78307bf mm/hugetlb: use helper huge_page_size() to get hugepage size
We can use helper huge_page_size() to get the hugepage size directly to
simplify the code slightly.

[linmiaohe@huawei.com: use helper huge_page_size() to get hugepage size]
  Link: https://lkml.kernel.org/r/20210209021803.49211-1-linmiaohe@huawei.com

Link: https://lkml.kernel.org/r/20210208082450.15716-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.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>
2021-02-24 13:38:33 -08:00
Miaohe Lin
3f1b0162f6 mm/hugetlb: remove unnecessary VM_BUG_ON_PAGE on putback_active_hugepage()
All callers know they are operating on a hugetlb head page.  So this
VM_BUG_ON_PAGE can not catch anything useful.

Link: https://lkml.kernel.org/r/20210209071151.44731-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:33 -08:00
Miaohe Lin
07e51edf83 mm/hugetlb: use helper function range_in_vma() in page_table_shareable()
We could use helper function range_in_vma() to check whether the vma is in
the desired range to simplify the code.

Link: https://lkml.kernel.org/r/20210204112949.43051-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:33 -08:00
Miaohe Lin
8938494c85 hugetlb_cgroup: use helper pages_per_huge_page() in hugetlb_cgroup
We could use helper function pages_per_huge_page() to get the number of
pages in a hstate to simplify the code slightly.

Link: https://lkml.kernel.org/r/20210205084513.29624-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.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>
2021-02-24 13:38:33 -08:00
Aneesh Kumar K.V
bae8495381 mm/pmem: avoid inserting hugepage PTE entry with fsdax if hugepage support is disabled
Differentiate between hardware not supporting hugepages and user disabling
THP via 'echo never > /sys/kernel/mm/transparent_hugepage/enabled'

For the devdax namespace, the kernel handles the above via the
supported_alignment attribute and failing to initialize the namespace if
the namespace align value is not supported on the platform.

For the fsdax namespace, the kernel will continue to initialize the
namespace.  This can result in the kernel creating a huge pte entry even
though the hardware don't support the same.

We do want hugepage support with pmem even if the end-user disabled THP
via sysfs file (/sys/kernel/mm/transparent_hugepage/enabled).  Hence
differentiate between hardware/firmware lacking support vs user-controlled
disable of THP and prevent a huge fault if the hardware lacks hugepage
support.

Link: https://lkml.kernel.org/r/20210205023956.417587-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:32 -08:00
Miaohe Lin
2efeb8da99 mm/huge_memory.c: remove unused return value of set_huge_zero_page()
The return value of set_huge_zero_page() is always ignored.  So we should
drop such return value.

Link: https://lkml.kernel.org/r/20210203084816.46307-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:32 -08:00
Zhiyuan Dai
578b7725d4 mm/hugetlb.c: fix typos in comments
Fix typo in comment.

Link: https://lkml.kernel.org/r/1612256106-9436-1-git-send-email-daizhiyuan@phytium.com.cn
Signed-off-by: Zhiyuan Dai <daizhiyuan@phytium.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:32 -08:00
Yanfei Xu
5291c09b3e mm/hugetlb: remove redundant check in preparing and destroying gigantic page
Gigantic page is a compound page and its order is more than 1.  Thus it
must be available for hpage_pincount.  Let's remove the redundant check
for gigantic page.

Link: https://lkml.kernel.org/r/20210202112002.73170-1-yanfei.xu@windriver.com
Signed-off-by: Yanfei Xu <yanfei.xu@windriver.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.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>
2021-02-24 13:38:32 -08:00
Miaohe Lin
6c26d31083 mm/hugetlb: fix some comment typos
Fix typos sasitfy to satisfy, reservtion to reservation, hugegpage to
hugepage and uniprocesor to uniprocessor in comments.

Link: https://lkml.kernel.org/r/20210128112028.64831-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:32 -08:00
Joao Martins
82e5d378b0 mm/hugetlb: refactor subpage recording
For a given hugepage backing a VA, there's a rather ineficient loop which
is solely responsible for storing subpages in GUP @pages/@vmas array.  For
each subpage we check whether it's within range or size of @pages and keep
increment @pfn_offset and a couple other variables per subpage iteration.

Simplify this logic and minimize the cost of each iteration to just store
the output page/vma.  Instead of incrementing number of @refs iteratively,
we do it through pre-calculation of @refs and only with a tight loop for
storing pinned subpages/vmas.

Additionally, retain existing behaviour with using mem_map_offset() when
recording the subpages for configurations that don't have a contiguous
mem_map.

pinning consequently improves bringing us close to
{pin,get}_user_pages_fast:

  - 16G with 1G huge page size
  gup_test -f /mnt/huge/file -m 16384 -r 30 -L -S -n 512 -w

PIN_LONGTERM_BENCHMARK: ~12.8k us -> ~5.8k us
PIN_FAST_BENCHMARK: ~3.7k us

Link: https://lkml.kernel.org/r/20210128182632.24562-3-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:32 -08:00
Joao Martins
0fa5bc4023 mm/hugetlb: grab head page refcount once for group of subpages
Patch series "mm/hugetlb: follow_hugetlb_page() improvements", v2.

While looking at ZONE_DEVICE struct page reuse particularly the last
patch[0], I found two possible improvements for follow_hugetlb_page()
which is solely used for get_user_pages()/pin_user_pages().

The first patch batches page refcount updates while the second tidies up
storing the subpages/vmas.  Both together bring the cost of slow variant
of gup() cost from ~87.6k usecs to ~5.8k usecs.

libhugetlbfs tests seem to pass as well gup_test benchmarks with hugetlbfs
vmas.

This patch (of 2):

follow_hugetlb_page() once it locks the pmd/pud, checks all its N subpages
in a huge page and grabs a reference for each one.  Similar to gup-fast,
have follow_hugetlb_page() grab the head page refcount only after counting
all its subpages that are part of the just faulted huge page.

Consequently we reduce the number of atomics necessary to pin said huge
page, which improves non-fast gup() considerably:

  - 16G with 1G huge page size
  gup_test -f /mnt/huge/file -m 16384 -r 10 -L -S -n 512 -w

PIN_LONGTERM_BENCHMARK: ~87.6k us -> ~12.8k us

Link: https://lkml.kernel.org/r/20210128182632.24562-1-joao.m.martins@oracle.com
Link: https://lkml.kernel.org/r/20210128182632.24562-2-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:32 -08:00
Jiapeng Zhong
c93b0a9926 mm/hugetlb: simplify the calculation of variables
Fix the following coccicheck warnings:

  mm/hugetlb.c:3372:20-22: WARNING !A || A && B is equivalent to !A || B.

Link: https://lkml.kernel.org/r/1611643468-52233-1-git-send-email-abaci-bugfix@linux.alibaba.com
Signed-off-by: Jiapeng Zhong <abaci-bugfix@linux.alibaba.com>
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:32 -08:00
Miaohe Lin
1d88433bb0 mm/hugetlb: fix use after free when subpool max_hpages accounting is not enabled
If a hugetlbfs filesystem is created with the min_size option and
without the size option, used_hpages is always 0 and might lead to
release subpool prematurely because it indicates no pages are used now
while there might be.

In order to fix this issue, we should check used_hpages == 0 iff
max_hpages accounting is enabled.  As max_hpages accounting should be
enabled in most common case, this is not worth a Cc stable.

[mike.kravetz@oracle.com: new changelog]

Link: https://lkml.kernel.org/r/20210126115510.53374-1-linmiaohe@huawei.com
Signed-off-by: Hongxiang Lou <louhongxiang@huawei.com>
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:32 -08:00
Miaohe Lin
c78a7f3639 mm/hugetlb: use helper huge_page_order and pages_per_huge_page
Since commit a551643895 ("hugetlb: modular state for hugetlb page
size"), we can use huge_page_order to access hstate->order and
pages_per_huge_page to fetch the pages per huge page.  But
gather_bootmem_prealloc() forgot to use it.

Link: https://lkml.kernel.org/r/20210114114435.40075-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:32 -08:00
Miaohe Lin
0aa7f3544a mm/hugetlb: avoid unnecessary hugetlb_acct_memory() call
When reservation accounting remains unchanged, hugetlb_acct_memory() will
do nothing except holding and releasing hugetlb_lock.  We should avoid
this unnecessary hugetlb_lock lock/unlock cycle which is happening on
'most' hugetlb munmap operations by check delta against 0 at the beginning
of hugetlb_acct_memory.

Link: https://lkml.kernel.org/r/20210115092013.61012-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:32 -08:00
Li Xinhai
a1ba9da8f0 mm/hugetlb.c: fix unnecessary address expansion of pmd sharing
The current code would unnecessarily expand the address range.  Consider
one example, (start, end) = (1G-2M, 3G+2M), and (vm_start, vm_end) =
(1G-4M, 3G+4M), the expected adjustment should be keep (1G-2M, 3G+2M)
without expand.  But the current result will be (1G-4M, 3G+4M).  Actually,
the range (1G-4M, 1G) and (3G, 3G+4M) would never been involved in pmd
sharing.

After this patch, we will check that the vma span at least one PUD aligned
size and the start,end range overlap the aligned range of vma.

With above example, the aligned vma range is (1G, 3G), so if (start, end)
range is within (1G-4M, 1G), or within (3G, 3G+4M), then no adjustment to
both start and end.  Otherwise, we will have chance to adjust start
downwards or end upwards without exceeding (vm_start, vm_end).

Mike:

: The 'adjusted range' is used for calls to mmu notifiers and cache(tlb)
: flushing.  Since the current code unnecessarily expands the range in some
: cases, more entries than necessary would be flushed.  This would/could
: result in performance degradation.  However, this is highly dependent on
: the user runtime.  Is there a combination of vma layout and calls to
: actually hit this issue?  If the issue is hit, will those entries
: unnecessarily flushed be used again and need to be unnecessarily reloaded?

Link: https://lkml.kernel.org/r/20210104081631.2921415-1-lixinhai.lxh@gmail.com
Fixes: 75802ca663 ("mm/hugetlb: fix calculation of adjust_range_if_pmd_sharing_possible")
Signed-off-by: Li Xinhai <lixinhai.lxh@gmail.com>
Suggested-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:32 -08:00
Miaohe Lin
cc2205a67d mm/hugetlb: fix potential double free in hugetlb_register_node() error path
In hugetlb_sysfs_add_hstate(), we would do kobject_put() on hstate_kobjs
when failed to create sysfs group but forget to set hstate_kobjs to NULL.
Then in hugetlb_register_node() error path, we may free it again via
hugetlb_unregister_node().

Link: https://lkml.kernel.org/r/20210107123249.36964-1-linmiaohe@huawei.com
Fixes: a343787016 ("hugetlb: new sysfs interface")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Muchun Song <smuchun@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:32 -08:00
Bibo Mao
aba677f94b MIPS: do not call flush_tlb_all when setting pmd entry
Function set_pmd_at is to set pmd entry, if tlb entry need to be flushed,
there exists pmdp_huge_clear_flush alike function before set_pmd_at is
called.  So it is not necessary to call flush_tlb_all in this function.

In these scenarios, tlb for the pmd range needs to be flushed:

 - privilege degrade such as wrprotect is set on the pmd entry

 - pmd entry is cleared

 - there is exception if set_pmd_at is issued by dup_mmap, since
   flush_tlb_mm is called for parent process, it is not necessary to
   flush tlb in function copy_huge_pmd.

Link: http://lkml.kernel.org/r/1592990792-1923-3-git-send-email-maobibo@loongson.cn
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Daniel Silsby <dansilsby@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:32 -08:00
Bibo Mao
fca40573e0 mm/huge_memory.c: update tlb entry if pmd is changed
When set_pmd_at is called in function do_huge_pmd_anonymous_page, new tlb
entry can be added by software on MIPS platform.

Here add update_mmu_cache_pmd when pmd entry is set, and
update_mmu_cache_pmd is defined as empty excepts arc/mips platform.  This
patch has no negative effect on other platforms except arc/mips system.

Link: http://lkml.kernel.org/r/1592990792-1923-2-git-send-email-maobibo@loongson.cn
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Daniel Silsby <dansilsby@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:32 -08:00
Aili Yao
30c9cf4927 mm,hwpoison: send SIGBUS to PF_MCE_EARLY processes on action required events
When a memory uncorrected error is triggered by process who accessed the
address with error, It's Action Required Case for only current process
which triggered this; This Action Required case means Action optional to
other process who share the same page.  Usually killing current process
will be sufficient, other processes sharing the same page will get be
signaled when they really touch the poisoned page.

But there is another scenario that other processes sharing the same page
want to be signaled early with PF_MCE_EARLY set.  In this case, we should
get them into kill list and signal BUS_MCEERR_AO to them.

So in this patch, task_early_kill will check current process if
force_early is set, and if not current,the code will fallback to
find_early_kill_thread() to check if there is PF_MCE_EARLY process who
cares the error.

In kill_proc(), BUS_MCEERR_AR is only send to current, other processes in
kill list will be signaled with BUS_MCEERR_AO.

Link: https://lkml.kernel.org/r/20210122132424.313c8f5f.yaoaili@kingsoft.com
Signed-off-by: Aili Yao <yaoaili@kingsoft.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:32 -08:00
Matthew Wilcox (Oracle)
3b2ebeaf98 mm/gfp: add kernel-doc for gfp_t
The generated html will link to the definition of the gfp_t automatically
once we define it.  Move the one-paragraph overview of GFP flags from the
documentation directory into gfp.h and pull gfp.h into the documentation.

This generates warnings with clang
(https://lkml.kernel.org/r/20210219195509.GA59987@24bbad8f3778), so
use a #if 0 to hide it from the compiler for now.

Link: https://lkml.kernel.org/r/20210215204909.3824509-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20210220003049.GZ2858050@casper.infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:32 -08:00
David Hildenbrand
a0cd7a7c4b mm: simplify free_highmem_page() and free_reserved_page()
adjust_managed_page_count() as called by free_reserved_page() properly
handles pages in a highmem zone, so we can reuse it for
free_highmem_page().

We can now get rid of totalhigh_pages_inc() and simplify
free_reserved_page().

Link: https://lkml.kernel.org/r/20210126182113.19892-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:32 -08:00