s390 for one, cannot implement VM_MIXEDMAP with pfn_valid, due to their memory
model (which is more dynamic than most). Instead, they had proposed to
implement it with an additional path through vm_normal_page(), using a bit in
the pte to determine whether or not the page should be refcounted:
vm_normal_page()
{
...
if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
if (vma->vm_flags & VM_MIXEDMAP) {
#ifdef s390
if (!mixedmap_refcount_pte(pte))
return NULL;
#else
if (!pfn_valid(pfn))
return NULL;
#endif
goto out;
}
...
}
This is fine, however if we are allowed to use a bit in the pte to determine
refcountedness, we can use that to _completely_ replace all the vma based
schemes. So instead of adding more cases to the already complex vma-based
scheme, we can have a clearly seperate and simple pte-based scheme (and get
slightly better code generation in the process):
vm_normal_page()
{
#ifdef s390
if (!mixedmap_refcount_pte(pte))
return NULL;
return pte_page(pte);
#else
...
#endif
}
And finally, we may rather make this concept usable by any architecture rather
than making it s390 only, so implement a new type of pte state for this.
Unfortunately the old vma based code must stay, because some architectures may
not be able to spare pte bits. This makes vm_normal_page a little bit more
ugly than we would like, but the 2 cases are clearly seperate.
So introduce a pte_special pte state, and use it in mm/memory.c. It is
currently a noop for all architectures, so this doesn't actually result in any
compiled code changes to mm/memory.o.
BTW:
I haven't put vm_normal_page() into arch code as-per an earlier suggestion.
The reason is that, regardless of where vm_normal_page is actually
implemented, the *abstraction* is still exactly the same. Also, while it
depends on whether the architecture has pte_special or not, that is the
only two possible cases, and it really isn't an arch specific function --
the role of the arch code should be to provide primitive functions and
accessors with which to build the core code; pte_special does that. We do
not want architectures to know or care about vm_normal_page itself, and
we definitely don't want them being able to invent something new there
out of sight of mm/ code. If we made vm_normal_page an arch function, then
we have to make vm_insert_mixed (next patch) an arch function too. So I
don't think moving it to arch code fundamentally improves any abstractions,
while it does practically make the code more difficult to follow, for both
mm and arch developers, and easier to misuse.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Carsten Otte <cotte@de.ibm.com>
Cc: Jared Hulbert <jaredeh@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This series introduces some important infrastructure work. The overall result
is that:
1. We now support XIP backed filesystems using memory that have no
struct page allocated to them. And patches 6 and 7 actually implement
this for s390.
This is pretty important in a number of cases. As far as I understand,
in the case of virtualisation (eg. s390), each guest may mount a
readonly copy of the same filesystem (eg. the distro). Currently,
guests need to allocate struct pages for this image. So if you have
100 guests, you already need to allocate more memory for the struct
pages than the size of the image. I think. (Carsten?)
For other (eg. embedded) systems, you may have a very large non-
volatile filesystem. If you have to have struct pages for this, then
your RAM consumption will go up proportionally to fs size. Even
though it is just a small proportion, the RAM can be much more costly
eg in terms of power, so every KB less that Linux uses makes it more
attractive to a lot of these guys.
2. VM_MIXEDMAP allows us to support mappings where you actually do want
to refcount _some_ pages in the mapping, but not others, and support
COW on arbitrary (non-linear) mappings. Jared needs this for his NVRAM
filesystem in progress. Future iterations of this filesystem will
most likely want to migrate pages between pagecache and XIP backing,
which is where the requirement for mixed (some refcounted, some not)
comes from.
3. pte_special also has a peripheral usage that I need for my lockless
get_user_pages patch. That was shown to speed up "oltp" on db2 by
10% on a 2 socket system, which is kind of significant because they
scrounge for months to try to find 0.1% improvement on these
workloads. I'm hoping we might finally be faster than AIX on
pSeries with this :). My reference to lockless get_user_pages is not
meant to justify this patchset (which doesn't include lockless gup),
but just to show that pte_special is not some s390 specific thing that
should be hidden in arch code or xip code: I definitely want to use it
on at least x86 and powerpc as well.
This patch:
Introduce a new type of mapping, VM_MIXEDMAP. This is unlike VM_PFNMAP in
that it can support COW mappings of arbitrary ranges including ranges without
struct page *and* ranges with a struct page that we actually want to refcount
(PFNMAP can only support COW in those cases where the un-COW-ed translations
are mapped linearly in the virtual address, and can only support non
refcounted ranges).
VM_MIXEDMAP achieves this by refcounting all pfn_valid pages, and not
refcounting !pfn_valid pages (which is not an option for VM_PFNMAP, because it
needs to avoid refcounting pfn_valid pages eg. for /dev/mem mappings).
Signed-off-by: Jared Hulbert <jaredeh@gmail.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Carsten Otte <cotte@de.ibm.com>
Cc: Jared Hulbert <jaredeh@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Having separate page flags for the head and the tail of a compound page allows
the compiler to use bitops instead of operations on a word to check for a tail
page. That is f.e. important for virt_to_head_page() which is used in
various critical code paths (kfree for example):
Code for PageTail(page)
Before:
mov (%rdi),%rdx page->flags
mov %rdx,%rax 3 bytes
and $0x12000,%eax 5 bytes
cmp $0x12000,%rax 6 bytes
je 897 <kfree+0xa7>
After:
mov (%rdi),%rax
test $0x40,%ah (3 bytes)
jne 887 <kfree+0x97>
So we go from 14 bytes to 3 bytes and from 3 instructions to one. From the
use of 2 registers we go to none.
We can only use page flags for this if we have page flags available. This
patch introduces CONFIG_PAGEFLAGS_EXTENDED that is set if pageflags are not
scarce due to SPARSEMEM using page flags for its sectionid on 32 bit NUMA
platforms.
Additional page flag definitions can be added to the CONFIG_PAGEFLAGS_EXTENDED
section in page-flags.h if the functionality depends on PAGEFLAGS_EXTENDED or
if more page flag overlapping tricks are used for the !PAGEFLAGS_EXTENDED
fallback (the upcoming virtual compound patch may hook in here and Rik's/Lee's
additional page flags to solve the reclaim issues could also be added there
[hint... hint... where are these patchsets?]).
Avoiding the overlaying of Pg_reclaim also clears the way for possible use of
compound pages for the pagecache or on the LRU.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove aliases of PG_xxx. We can easily drop those now and alias by
specifying the PG_xxx flag in the macro that generates the functions.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Implement a new proc file that allows the display of the currently allocated
vmalloc memory.
It allows to see the users of vmalloc. That is important if vmalloc space is
scarce (i386 for example).
And it's going to be important for the compound page fallback to vmalloc.
Many of the current users can be switched to use compound pages with fallback.
This means that the number of users of vmalloc is reduced and page tables no
longer necessary to access the memory. /proc/vmallocinfo allows to review how
that reduction occurs.
If memory becomes fragmented and larger order allocations are no longer
possible then /proc/vmallocinfo allows to see which compound page allocations
fell back to virtual compound pages. That is important for new users of
virtual compound pages. Such as order 1 stack allocation etc that may
fallback to virtual compound pages in the future.
/proc/vmallocinfo permissions are made readable-only-by-root to avoid possible
information leakage.
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: CONFIG_MMU=n build fix]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Clean up messy conditional calling of test_clear_page_writeback() from both
rotate_reclaimable_page() and end_page_writeback().
The only user of rotate_reclaimable_page() is end_page_writeback() so this is
OK.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Previously it was only enabled for CONFIG_DEBUG_SLAB.
Not hooked into the slub runtime debug configuration, so you currently only
get it with CONFIG_SLUB_DEBUG_ON, not plain CONFIG_SLUB_DEBUG
Acked-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Parsing of new mode flags in the tmpfs mpol mount option is slightly broken:
Setting a valid flag works OK:
#mount -o remount,mpol=bind=static:1-2 /dev/shm
#mount
...
tmpfs on /dev/shm type tmpfs (rw,mpol=bind=static:1-2)
...
However, we can't remove them or change them, once we've
set a valid flag:
#mount -o remount,mpol=bind:1-2 /dev/shm
#mount
...
tmpfs on /dev/shm type tmpfs (rw,mpol=bind:1-2)
...
It SAYS it removed it, but that's just a copy of the input
string. If we now try to set it to a different flag, we
get:
#mount -o remount,mpol=bind=relative:1-2 /dev/shm
mount: /dev/shm not mounted already, or bad option
And on the console, we see:
tmpfs: Bad value 'bind' for mount option 'mpol'
^ lost remainder of string
Furthermore, bogus flags are accepted with out error.
Granted, they are a no-op:
#mount -o remount,mpol=interleave=foo:0-3 /dev/shm
#mount
...
tmpfs on /dev/shm type tmpfs (rw,mpol=interleave=foo:0-3)
Again, that's just a copy of the input string shown by the mount command.
This patch fixes the behavior by pre-zeroing the flags so that only one of the
mutually exclusive flags can be set at one time. It also reports an error
when an unrecognized flag is specified.
The check for both flags being set is removed because it can't happen with
this implementation. If we ever want to support multiple non-exclusive flags,
this area will need rework and we will need to check that any mutually
exclusive flags aren't specified.
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Eric Whitney <eric.whitney@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
MPOL_F_STATIC_NODES and MPOL_F_RELATIVE_NODES don't mean anything for
MPOL_PREFERRED policies that were created with an empty nodemask (for purely
local allocations). They'll never be invalidated because the allowed mems of
a task changes or need to be rebound relative to a cpuset's placement.
Also fixes a bug identified by Lee Schermerhorn that disallowed empty
nodemasks to be passed to MPOL_PREFERRED to specify local allocations. [A
different, somewhat incomplete, patch already existed in 25-rc5-mm1.]
Cc: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Create a mempolicy_operations structure that currently points to two
functions[*] for the various modes:
int (*create)(struct mempolicy *, const nodemask_t *);
void (*rebind)(struct mempolicy *, const nodemask_t *);
This splits the implementation for the various modes out of two large
functions, mpol_new() and mpol_rebind_policy(). Eventually it may be
beneficial to add additional functions to accomodate the existing switch()
statements in mm/mempolicy.c.
[*] The ->create() function for MPOL_DEFAULT is currently NULL since no
struct mempolicy is dynamically allocated.
[Lee.Schermerhorn@hp.com: fix regression in the package mempolicy regression tests]
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Eric Whitney <eric.whitney@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move the mpol_rebind_{policy,task,mm}() functions after mpol_new() to avoid
having to declare function prototypes.
Cc: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Adds another optional mode flag, MPOL_F_RELATIVE_NODES, that specifies
nodemasks passed via set_mempolicy() or mbind() should be considered relative
to the current task's mems_allowed.
When the mempolicy is created, the passed nodemask is folded and mapped onto
the current task's mems_allowed. For example, consider a task using
set_mempolicy() to pass MPOL_INTERLEAVE | MPOL_F_RELATIVE_NODES with a
nodemask of 1-3. If current's mems_allowed is 4-7, the effected nodemask is
5-7 (the second, third, and fourth node of mems_allowed).
If the same task is attached to a cpuset, the mempolicy nodemask is rebound
each time the mems are changed. Some possible rebinds and results are:
mems result
1-3 1-3
1-7 2-4
1,5-6 1,5-6
1,5-7 5-7
Likewise, the zonelist built for MPOL_BIND acts on the set of zones assigned
to the resultant nodemask from the relative remap.
In the MPOL_PREFERRED case, the preferred node is remapped from the currently
effected nodemask to the relative nodemask.
This mempolicy mode flag was conceived of by Paul Jackson <pj@sgi.com>.
Cc: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add an optional mempolicy mode flag, MPOL_F_STATIC_NODES, that suppresses the
node remap when the policy is rebound.
Adds another member to struct mempolicy, nodemask_t user_nodemask, as part of
a union with cpuset_mems_allowed:
struct mempolicy {
...
union {
nodemask_t cpuset_mems_allowed;
nodemask_t user_nodemask;
} w;
}
that stores the the nodemask that the user passed when he or she created the
mempolicy via set_mempolicy() or mbind(). When using MPOL_F_STATIC_NODES,
which is passed with any mempolicy mode, the user's passed nodemask
intersected with the VMA or task's allowed nodes is always used when
determining the preferred node, setting the MPOL_BIND zonelist, or creating
the interleave nodemask. This happens whenever the policy is rebound,
including when a task's cpuset assignment changes or the cpuset's mems are
changed.
This creates an interesting side-effect in that it allows the mempolicy
"intent" to lie dormant and uneffected until it has access to the node(s) that
it desires. For example, if you currently ask for an interleaved policy over
a set of nodes that you do not have access to, the mempolicy is not created
and the task continues to use the previous policy. With this change, however,
it is possible to create the same mempolicy; it is only effected when access
to nodes in the nodemask is acquired.
It is also possible to mount tmpfs with the static nodemask behavior when
specifying a node or nodemask. To do this, simply add "=static" immediately
following the mempolicy mode at mount time:
mount -o remount mpol=interleave=static:1-3
Also removes mpol_check_policy() and folds its logic into mpol_new() since it
is now obsoleted. The unused vma_mpol_equal() is also removed.
Cc: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With the evolution of mempolicies, it is necessary to support mempolicy mode
flags that specify how the policy shall behave in certain circumstances. The
most immediate need for mode flag support is to suppress remapping the
nodemask of a policy at the time of rebind.
Both the mempolicy mode and flags are passed by the user in the 'int policy'
formal of either the set_mempolicy() or mbind() syscall. A new constant,
MPOL_MODE_FLAGS, represents the union of legal optional flags that may be
passed as part of this int. Mempolicies that include illegal flags as part of
their policy are rejected as invalid.
An additional member to struct mempolicy is added to support the mode flags:
struct mempolicy {
...
unsigned short policy;
unsigned short flags;
}
The splitting of the 'int' actual passed by the user is done in
sys_set_mempolicy() and sys_mbind() for their respective syscalls. This is
done by intersecting the actual with MPOL_MODE_FLAGS, rejecting the syscall of
there are additional flags, and storing it in the new 'flags' member of struct
mempolicy. The intersection of the actual with ~MPOL_MODE_FLAGS is stored in
the 'policy' member of the struct and all current users of pol->policy remain
unchanged.
The union of the policy mode and optional mode flags is passed back to the
user in get_mempolicy().
This combination of mode and flags within the same actual does not break
userspace code that relies on get_mempolicy(&policy, ...) and either
switch (policy) {
case MPOL_BIND:
...
case MPOL_INTERLEAVE:
...
};
statements or
if (policy == MPOL_INTERLEAVE) {
...
}
statements. Such applications would need to use optional mode flags when
calling set_mempolicy() or mbind() for these previously implemented statements
to stop working. If an application does start using optional mode flags, it
will need to mask the optional flags off the policy in switch and conditional
statements that only test mode.
An additional member is also added to struct shmem_sb_info to store the
optional mode flags.
[hugh@veritas.com: shmem mpol: fix build warning]
Cc: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The mempolicy mode constants, MPOL_DEFAULT, MPOL_PREFERRED, MPOL_BIND, and
MPOL_INTERLEAVE, are better declared as part of an enum since they are
sequentially numbered and cannot be combined.
The policy member of struct mempolicy is also converted from type short to
type unsigned short. A negative policy does not have any legitimate meaning,
so it is possible to change its type in preparation for adding optional mode
flags later.
The equivalent member of struct shmem_sb_info is also changed from int to
unsigned short.
For compatibility, the policy formal to get_mempolicy() remains as a pointer
to an int:
int get_mempolicy(int *policy, unsigned long *nmask,
unsigned long maxnode, unsigned long addr,
unsigned long flags);
although the only possible values is the range of type unsigned short.
Cc: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Not all architectures define cache_line_size() so as suggested by Andrew move
the private implementations in mm/slab.c and mm/slob.c to <linux/cache.h>.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To reduce hugetlb_lock acquisitions and releases when freeing excess surplus
pages, scan the page list in two parts. First, transfer the needed pages to
the hugetlb pool. Then drop the lock and free the remaining pages back to the
buddy allocator.
In the common case there are zero excess pages and no lock operations are
required.
Thanks Mel Gorman for this improvement.
Signed-off-by: Adam Litke <agl@us.ibm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When checking for the swap header try byteswapping the endianess dependent
fields to allow the swap partition to be shared between big & little endian
systems.
Signed-off-by: Chris Dearman <chris@mips.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The MPOL_BIND policy creates a zonelist that is used for allocations
controlled by that mempolicy. As the per-node zonelist is already being
filtered based on a zone id, this patch adds a version of __alloc_pages() that
takes a nodemask for further filtering. This eliminates the need for
MPOL_BIND to create a custom zonelist.
A positive benefit of this is that allocations using MPOL_BIND now use the
local node's distance-ordered zonelist instead of a custom node-id-ordered
zonelist. I.e., pages will be allocated from the closest allowed node with
available memory.
[Lee.Schermerhorn@hp.com: Mempolicy: update stale documentation and comments]
[Lee.Schermerhorn@hp.com: Mempolicy: make dequeue_huge_page_vma() obey MPOL_BIND nodemask]
[Lee.Schermerhorn@hp.com: Mempolicy: make dequeue_huge_page_vma() obey MPOL_BIND nodemask rework]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Filtering zonelists requires very frequent use of zone_idx(). This is costly
as it involves a lookup of another structure and a substraction operation. As
the zone_idx is often required, it should be quickly accessible. The node idx
could also be stored here if it was found that accessing zone->node is
significant which may be the case on workloads where nodemasks are heavily
used.
This patch introduces a struct zoneref to store a zone pointer and a zone
index. The zonelist then consists of an array of these struct zonerefs which
are looked up as necessary. Helpers are given for accessing the zone index as
well as the node index.
[kamezawa.hiroyu@jp.fujitsu.com: Suggested struct zoneref instead of embedding information in pointers]
[hugh@veritas.com: mm-have-zonelist: fix memcg ooms]
[hugh@veritas.com: just return do_try_to_free_pages]
[hugh@veritas.com: do_try_to_free_pages gfp_mask redundant]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Christoph Lameter <clameter@sgi.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently a node has two sets of zonelists, one for each zone type in the
system and a second set for GFP_THISNODE allocations. Based on the zones
allowed by a gfp mask, one of these zonelists is selected. All of these
zonelists consume memory and occupy cache lines.
This patch replaces the multiple zonelists per-node with two zonelists. The
first contains all populated zones in the system, ordered by distance, for
fallback allocations when the target/preferred node has no free pages. The
second contains all populated zones in the node suitable for GFP_THISNODE
allocations.
An iterator macro is introduced called for_each_zone_zonelist() that interates
through each zone allowed by the GFP flags in the selected zonelist.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On NUMA, zone_statistics() is used to record events like numa hit, miss and
foreign. It assumes that the first zone in a zonelist is the preferred zone.
When multiple zonelists are replaced by one that is filtered, this is no
longer the case.
This patch records what the preferred zone is rather than assuming the first
zone in the zonelist is it. This simplifies the reading of later patches in
this set.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <clameter@sgi.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduce a node_zonelist() helper function. It is used to lookup the
appropriate zonelist given a node and a GFP mask. The patch on its own is a
cleanup but it helps clarify parts of the two-zonelist-per-node patchset. If
necessary, it can be merged with the next patch in this set without problems.
Reviewed-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The following patches replace multiple zonelists per node with two zonelists
that are filtered based on the GFP flags. The patches as a set fix a bug with
regard to the use of MPOL_BIND and ZONE_MOVABLE. With this patchset, the
MPOL_BIND will apply to the two highest zones when the highest zone is
ZONE_MOVABLE. This should be considered as an alternative fix for the
MPOL_BIND+ZONE_MOVABLE in 2.6.23 to the previously discussed hack that filters
only custom zonelists.
The first patch cleans up an inconsistency where direct reclaim uses
zonelist->zones where other places use zonelist.
The second patch introduces a helper function node_zonelist() for looking up
the appropriate zonelist for a GFP mask which simplifies patches later in the
set.
The third patch defines/remembers the "preferred zone" for numa statistics, as
it is no longer always the first zone in a zonelist.
The forth patch replaces multiple zonelists with two zonelists that are
filtered. The two zonelists are due to the fact that the memoryless patchset
introduces a second set of zonelists for __GFP_THISNODE.
The fifth patch introduces helper macros for retrieving the zone and node
indices of entries in a zonelist.
The final patch introduces filtering of the zonelists based on a nodemask.
Two zonelists exist per node, one for normal allocations and one for
__GFP_THISNODE.
Performance results varied depending on the machine configuration. In real
workloads the gain/loss will depend on how much the userspace portion of the
benchmark benefits from having more cache available due to reduced referencing
of zonelists.
These are the range of performance losses/gains when running against
2.6.24-rc4-mm1. The set and these machines are a mix of i386, x86_64 and
ppc64 both NUMA and non-NUMA.
loss to gain
Total CPU time on Kernbench: -0.86% to 1.13%
Elapsed time on Kernbench: -0.79% to 0.76%
page_test from aim9: -4.37% to 0.79%
brk_test from aim9: -0.71% to 4.07%
fork_test from aim9: -1.84% to 4.60%
exec_test from aim9: -0.71% to 1.08%
This patch:
The allocator deals with zonelists which indicate the order in which zones
should be targeted for an allocation. Similarly, direct reclaim of pages
iterates over an array of zones. For consistency, this patch converts direct
reclaim to use a zonelist. No functionality is changed by this patch. This
simplifies zonelist iterators in the next patch.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nothing in the tree uses nopage any more. Remove support for it in the
core mm code and documentation (and a few stray references to it in
comments).
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is not easy to actually understand the "if (!file || !vma_merge())"
code, turn it into "if (file && vma_merge())". This makes immediately
obvious that the subsequent "if (file)" is superfluous.
As Hugh Dickins pointed out, we can also factor out the ->i_writecount
corrections, and add a small comment about that.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
DIO invalidates page cache through invalidate_inode_pages2_range().
invalidate_inode_pages2_range() sets ret=-EIO when
invalidate_complete_page2() fails, but this ret is cleared if
do_launder_page() succeed on a page of next index.
In this case, dio is carried out even if invalidate_complete_page2() fails
on some pages.
This can cause inconsistency between memory and blocks on HDD because the
page cache still exists.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Ken Chen <kenchen@google.com>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Chuck Lever <cel@citi.umich.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
All architectures use an effectively identical definition of online_page(), so
just make it common code. x86-64, ia64, powerpc and sh are actually
identical; x86-32 is slightly different.
x86-32's differences arise because it puts its hotplug pages in the highmem
zone. We can handle this in the generic code by inspecting the page to see if
its in highmem, and update the totalhigh_pages count appropriately. This
leaves init_32.c:free_new_highpage with a single caller, so I folded it into
add_one_highpage_init.
I also removed an incorrect comment referring to the NUMA case; any NUMA
details have already been dealt with by the time online_page() is called.
[akpm@linux-foundation.org: fix indenting]
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Dave Hansen <dave@linux.vnet.ibm.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamez.hiroyu@jp.fujitsu.com>
Tested-by: KAMEZAWA Hiroyuki <kamez.hiroyu@jp.fujitsu.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Christoph Lameter <clameter@sgi.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Generic helper function to remove section mappings and sysfs entries for the
section of the memory we are removing. offline_pages() correctly adjusted
zone and marked the pages reserved.
TODO: Yasunori Goto is working on patches to free up allocations from bootmem.
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Acked-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After the loop in walk_pte_range() pte might point to the first address after
the pmd it walks. The pte_unmap() is then applied to something bad.
Spotted by Roel Kluin and Andreas Schwab.
Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Cc: Roel Kluin <12o3l@tiscali.nl>
Cc: Andreas Schwab <schwab@suse.de>
Acked-by: Matt Mackall <mpm@selenic.com>
Acked-by: Mikael Pettersson <mikpe@it.uu.se>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since we now have more orders available use a denser packing.
Increase slab order if more than 1/16th of a slab would be wasted.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
The mininum objects per slab is calculated based on the number of processors
that may come online.
Processors min_objects
---------------------------
1 8
2 12
4 16
8 20
16 24
32 28
64 32
1024 48
4096 56
The higher the number of processors the large the order sizes used for various
slab caches will become. This has been shown to address the performance issues
in hackbench on 16p etc.
The calculation is only performed if slub_min_objects is zero (default). If one
specifies a slub_min_objects on boot then that setting is taken.
As suggested by Zhang Yanmin's performance tests on 16-core Tigerton, use the
formula '4 * (fls(nr_cpu_ids) + 1)':
./hackbench 100 process 2000:
1) 2.6.25-rc6slab: 23.5 seconds
2) 2.6.25-rc7SLUB+slub_min_objects=20: 31 seconds
3) 2.6.25-rc7SLUB+slub_min_objects=24: 23.5 seconds
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
We can now fallback to order 0 slabs. So set the slub_max_order to
PAGE_CACHE_ORDER_COSTLY but keep the slub_min_objects at 4. This
will mostly preserve the orders used in 2.6.25. F.e. The 2k kmalloc slab
will use order 1 allocs and the 4k kmalloc slab order 2.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Since we now have total_objects counter per node use that to
check for the presence of any objects. The loop over all cpu slabs
is not that useful since any cpu slab would require an object allocation
first. So drop that.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Makes /sys/kernel/slab/<slabname>/order writable. The allocation
order of a slab cache can then be changed dynamically during runtime.
This can be used to override the objects per slabs value establisheed
with the slub_min_objects setting that was manually specified or
calculated on bootup.
The changes of the slab order can occur while allocate_slab() runs.
Allocate slab needs the order and the number of slab objects that
are both changed by the change of order. Both are put into
a single word (struct kmem_cache_order_objects). They can then
be atomically updated and retrieved.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
There is now a generic method of falling back to a slab page of minimal
order. No need anymore for the fallback to kmalloc_large().
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
If any higher order allocation fails then fall back the smallest order
necessary to contain at least one object. This enables fallback for all
allocations to order 0 pages. The fallback will waste more memory (objects
will not fit neatly) and the fallback slabs will be not as efficient as larger
slabs since they contain less objects.
Note that SLAB also depends on order 1 allocations for some slabs that waste
too much memory if forced into PAGE_SIZE'd page. SLUB now can now deal with
failing order 1 allocs which SLAB cannot do.
Add a new field min that will contain the objects for the smallest possible order
for a slab cache.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Change the statistics to consider that slabs of the same slabcache
can have different number of objects in them since they may be of
different order.
Provide a new sysfs field
total_objects
which shows the total objects that the allocated slabs of a slabcache
could hold.
Add a max field that holds the largest slab order that was ever used
for a slab cache.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Pack the order and the number of objects into a single word.
This saves some memory in the kmem_cache_structure and more importantly
allows us to fetch both values atomically.
Later the slab orders become runtime configurable and we need to fetch these
two items together in order to properly allocate a slab and initialize its
objects.
Fix the race by fetching the order and the number of objects in one word.
[penberg@cs.helsinki.fi: fix memset() page order in new_slab()]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Pass the number of objects to the for_each_object macro. Most of these are
debug related.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Split the inuse field up to be able to store the number of objects in this
page in the page struct as well. Necessary if we want to have pages of
various orders for a slab. Also avoids touching struct kmem_cache cachelines in
__slab_alloc().
Update diagnostic code to check the number of objects and make sure that
the number of objects always stays within the bounds of a 16 bit unsigned
integer.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Dump a list of unfreed objects if a slab cache is closed but
objects still remain.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
free_list looked a bit screwy so here is an attempt to clean it up.
free_list is is only used for freeing partial lists. We do not need to return a
parameter if we decrement nr_partial within the function which allows a
simplification of the whole thing.
The current version modifies nr_partial outside of the list_lock which is
technically not correct. It was only ok because we should be the only user of
this slab cache at this point.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
As pointed out by Ingo, the SLUB warning of calling kmem_cache_destroy()
with cache that still has objects triggers in practice. So turn this
WARN_ON() into a nice SLUB specific error message to avoid people
confusing it to a SLUB bug.
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
This may trigger misaligned memory access exception.
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
This patch changes the s390 memory management defintions to use the pgste field
for dirty and reference bit tracking of host and guest code. Usually on s390,
dirty and referenced are tracked in storage keys, which belong to the physical
page. This changes with virtualization: The guest and host dirty/reference bits
are defined to be the logical OR of the values for the mapping and the physical
page. This patch implements the necessary changes in pgtable.h for s390.
There is a common code change in mm/rmap.c, the call to
page_test_and_clear_young must be moved. This is a no-op for all
architecture but s390. page_referenced checks the referenced bits for
the physiscal page and for all mappings:
o The physical page is checked with page_test_and_clear_young.
o The mappings are checked with ptep_test_and_clear_young and friends.
Without pgstes (the current implementation on Linux s390) the physical page
check is implemented but the mapping callbacks are no-ops because dirty
and referenced are not tracked in the s390 page tables. The pgstes introduces
guest and host dirty and reference bits for s390 in the host mapping. These
mapping must be checked before page_test_and_clear_young resets the reference
bit.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
On big systems with lots of memory, don't print out too much during
bootup, and make it easy to find if it is continuous.
on 256G 8 sockets system will get
[ffffe20000000000-ffffe20002bfffff] PMD -> [ffff810001400000-ffff810003ffffff] on node 0
[ffffe2001c700000-ffffe2001c7fffff] potential offnode page_structs
[ffffe20002c00000-ffffe2001c7fffff] PMD -> [ffff81000c000000-ffff8100255fffff] on node 0
[ffffe20038700000-ffffe200387fffff] potential offnode page_structs
[ffffe2001c800000-ffffe200387fffff] PMD -> [ffff810820200000-ffff81083c1fffff] on node 1
[ffffe20040000000-ffffe2007fffffff] PUD ->ffff811027a00000 on node 2
[ffffe20038800000-ffffe2003fffffff] PMD -> [ffff811020200000-ffff8110279fffff] on node 2
[ffffe20054700000-ffffe200547fffff] potential offnode page_structs
[ffffe20040000000-ffffe200547fffff] PMD -> [ffff811027c00000-ffff81103c3fffff] on node 2
[ffffe20070700000-ffffe200707fffff] potential offnode page_structs
[ffffe20054800000-ffffe200707fffff] PMD -> [ffff811820200000-ffff81183c1fffff] on node 3
[ffffe20080000000-ffffe200bfffffff] PUD ->ffff81202fa00000 on node 4
[ffffe20070800000-ffffe2007fffffff] PMD -> [ffff812020200000-ffff81202f9fffff] on node 4
[ffffe2008c700000-ffffe2008c7fffff] potential offnode page_structs
[ffffe20080000000-ffffe2008c7fffff] PMD -> [ffff81202fc00000-ffff81203c3fffff] on node 4
[ffffe200a8700000-ffffe200a87fffff] potential offnode page_structs
[ffffe2008c800000-ffffe200a87fffff] PMD -> [ffff812820200000-ffff81283c1fffff] on node 5
[ffffe200c0000000-ffffe200ffffffff] PUD ->ffff813037a00000 on node 6
[ffffe200a8800000-ffffe200bfffffff] PMD -> [ffff813020200000-ffff8130379fffff] on node 6
[ffffe200c4700000-ffffe200c47fffff] potential offnode page_structs
[ffffe200c0000000-ffffe200c47fffff] PMD -> [ffff813037c00000-ffff81303c3fffff] on node 6
[ffffe200c4800000-ffffe200e07fffff] PMD -> [ffff813820200000-ffff81383c1fffff] on node 7
instead of a very long print out...
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
split reserve_bootmem_core() into two functions, one which checks
conflicts, and one which sets the bits.
and make reserve_bootmem to loop bdata_list to cross the nodes.
user could be crashkernel and ramdisk..., in case the range provided
by those externalities crosses the nodes.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
need offset alignment when node_boot_start's alignment is less than
the alignment required.
use local node_boot_start to match alignment - so don't add extra operation
in search loop.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Make the nodes other than node 0 use bdata->last_success for fast
search too.
We need to use __alloc_bootmem_core() for vmemmap allocation for other
nodes when numa and sparsemem/vmemmap are enabled.
Also, make fail_block path increase i with incr only after ALIGN
to avoid extra increase when size is larger than align.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
vmemmap allocation currently has this layout:
[ffffe20000000000-ffffe200001fffff] PMD ->ffff810001400000 on node 0
[ffffe20000200000-ffffe200003fffff] PMD ->ffff810001800000 on node 0
[ffffe20000400000-ffffe200005fffff] PMD ->ffff810001c00000 on node 0
[ffffe20000600000-ffffe200007fffff] PMD ->ffff810002000000 on node 0
[ffffe20000800000-ffffe200009fffff] PMD ->ffff810002400000 on node 0
...
note that there is a 2M hole between them - not optimal.
the root cause is that usemap (24 bytes) will be allocated after every 2M
mem_map, and it will push next vmemmap (2M) to the next (2M) alignment.
solution: try to allocate the mem_map continously.
after the patch, we get:
[ffffe20000000000-ffffe200001fffff] PMD ->ffff810001400000 on node 0
[ffffe20000200000-ffffe200003fffff] PMD ->ffff810001600000 on node 0
[ffffe20000400000-ffffe200005fffff] PMD ->ffff810001800000 on node 0
[ffffe20000600000-ffffe200007fffff] PMD ->ffff810001a00000 on node 0
[ffffe20000800000-ffffe200009fffff] PMD ->ffff810001c00000 on node 0
...
which is the ideal layout.
and usemap will share a page because of they are allocated continuously too:
sparse_early_usemap_alloc: usemap = ffff810024e00000 size = 24
sparse_early_usemap_alloc: usemap = ffff810024e00080 size = 24
sparse_early_usemap_alloc: usemap = ffff810024e00100 size = 24
sparse_early_usemap_alloc: usemap = ffff810024e00180 size = 24
...
so we make the bootmem allocation more compact and use less memory
for usemap => mission accomplished ;-)
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/juhl/trivial: (24 commits)
DOC: A couple corrections and clarifications in USB doc.
Generate a slightly more informative error msg for bad HZ
fix typo "is" -> "if" in Makefile
ext*: spelling fix prefered -> preferred
DOCUMENTATION: Use newer DEFINE_SPINLOCK macro in docs.
KEYS: Fix the comment to match the file name in rxrpc-type.h.
RAID: remove trailing space from printk line
DMA engine: typo fixes
Remove unused MAX_NODES_SHIFT
MAINTAINERS: Clarify access to OCFS2 development mailing list.
V4L: Storage class should be before const qualifier (sn9c102)
V4L: Storage class should be before const qualifier
sonypi: Storage class should be before const qualifier
intel_menlow: Storage class should be before const qualifier
DVB: Storage class should be before const qualifier
arm: Storage class should be before const qualifier
ALSA: Storage class should be before const qualifier
acpi: Storage class should be before const qualifier
firmware_sample_driver.c: fix coding style
MAINTAINERS: Add ati_remote2 driver
...
Fixed up trivial conflicts in firmware_sample_driver.c
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-2.6: (36 commits)
SCSI: convert struct class_device to struct device
DRM: remove unused dev_class
IB: rename "dev" to "srp_dev" in srp_host structure
IB: convert struct class_device to struct device
memstick: convert struct class_device to struct device
driver core: replace remaining __FUNCTION__ occurrences
sysfs: refill attribute buffer when reading from offset 0
PM: Remove destroy_suspended_device()
Firmware: add iSCSI iBFT Support
PM: Remove legacy PM (fix)
Kobject: Replace list_for_each() with list_for_each_entry().
SYSFS: Explicitly include required header file slab.h.
Driver core: make device_is_registered() work for class devices
PM: Convert wakeup flag accessors to inline functions
PM: Make wakeup flags available whenever CONFIG_PM is set
PM: Fix misuse of wakeup flag accessors in serial core
Driver core: Call device_pm_add() after bus_add_device() in device_add()
PM: Handle device registrations during suspend/resume
block: send disk "change" event for rescan_partitions()
sysdev: detect multiple driver registrations
...
Fixed trivial conflict in include/linux/memory.h due to semaphore header
file change (made irrelevant by the change to mutex).
These are small cleanups all over the tree.
Trivial style and comment changes to
fs/select.c, kernel/signal.c, kernel/stop_machine.c & mm/pdflush.c
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
* Use new node_to_cpumask_ptr. This creates a pointer to the
cpumask for a given node. This definition is in mm patch:
asm-generic-add-node_to_cpumask_ptr-macro.patch
* Use new set_cpus_allowed_ptr function.
Depends on:
[mm-patch]: asm-generic-add-node_to_cpumask_ptr-macro.patch
[sched-devel]: sched: add new set_cpus_allowed_ptr function
[x86/latest]: x86: add cpus_scnprintf function
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Greg Banks <gnb@melbourne.sgi.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Modify cpuset_cpus_allowed to return the currently allowed cpuset
via a pointer argument instead of as the function return value.
* Use new set_cpus_allowed_ptr function.
* Cleanup CPU_MASK_ALL and NODE_MASK_ALL uses.
Depends on:
[sched-devel]: sched: add new set_cpus_allowed_ptr function
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Replace usages of CPU_MASK_NONE, CPU_MASK_ALL, NODE_MASK_NONE,
NODE_MASK_ALL to reduce stack requirements for large NR_CPUS
and MAXNODES counts.
* In some cases, the cpumask variable was initialized but then overwritten
with another value. This is the case for changes like this:
- cpumask_t oldmask = CPU_MASK_ALL;
+ cpumask_t oldmask;
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
slub: No need for per node slab counters if !SLUB_DEBUG
slub: Move map/flag clearing to __free_slab
slub: Fixes to per cpu stat output in sysfs
slub: Deal with config variable dependencies
slub: Reduce #ifdef ZONE_DMA by moving kmalloc_caches_dma near dma logic
slub: Initialize per-cpu stats
Fix two regressions dealing with the kgdb core.
1) kgdb_skipexception and kgdb_post_primary_code are optional
functions that are only required on archs that need special exception
fixups.
2) The kernel address space scope must be set on any probe_kernel_*
function or archs such as ARCH=arm will not allow access to the kernel
memory space. As an example, it is required to allow the full kernel
address space is when you the kernel debugger to inspect a system
call.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
add probe_kernel_read() and probe_kernel_write().
Uninlined and restricted to kernel range memory only, as suggested
by Linus.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Fix memory corruption and crash on 32-bit x86 systems.
If a !PAE x86 kernel is booted on a 32-bit system with more than 4GB of
RAM, then we call memory_present() with a start/end that goes outside
the scope of MAX_PHYSMEM_BITS.
That causes this loop to happily walk over the limit of the sparse
memory section map:
for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
unsigned long section = pfn_to_section_nr(pfn);
struct mem_section *ms;
sparse_index_init(section, nid);
set_section_nid(section, nid);
ms = __nr_to_section(section);
if (!ms->section_mem_map)
ms->section_mem_map = sparse_encode_early_nid(nid) |
SECTION_MARKED_PRESENT;
'ms' will be out of bounds and we'll corrupt a small amount of memory by
encoding the node ID and writing SECTION_MARKED_PRESENT (==0x1) over it.
The corruption might happen when encoding a non-zero node ID, or due to
the SECTION_MARKED_PRESENT which is 0x1:
mmzone.h:#define SECTION_MARKED_PRESENT (1UL<<0)
The fix is to sanity check anything the architecture passes to
sparsemem.
This bug seems to be rather old (as old as sparsemem support itself),
but the exact incarnation depended on random details like configs, which
made this bug more prominent in v2.6.25-to-be.
An additional enhancement might be to print a warning about ignored or
trimmed memory ranges.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Tested-by: Christoph Lameter <clameter@sgi.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Yinghai Lu <Yinghai.Lu@sun.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The per node counters are used mainly for showing data through the sysfs API.
If that API is not compiled in then there is no point in keeping track of this
data. Disable counters for the number of slabs and the number of total slabs
if !SLUB_DEBUG. Incrementing the per node counters is also accessing a
potentially contended cacheline so this could actually be a performance
benefit to embedded systems.
SLABINFO support is also affected. It now must depends on SLUB_DEBUG (which
is on by default).
Patch also avoids a check for a NULL kmem_cache_node pointer in new_slab()
if the system is not compiled with NUMA support.
[penberg@cs.helsinki.fi: fix oops and move ->nr_slabs into CONFIG_SLUB_DEBUG]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
__free_slab does some diagnostics. The resetting of mapcount etc
in discard_slab() can interfere with debug processing. So move
the reset immediately before the page is freed.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Only output per cpu stats if the kernel is build for SMP.
Use a capital "C" as a leading character for the processor number
(same as the numa statistics that also use a capital letter "N").
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
count_partial() is used by both slabinfo and the sysfs proc support. Move
the function directly before the beginning of the sysfs code so that it can
be easily found. Rework the preprocessor conditional to take into account
that slub sysfs support depends on CONFIG_SYSFS *and* CONFIG_SLUB_DEBUG.
Make CONFIG_SLUB_STATS depend on CONFIG_SLUB_DEBUG and CONFIG_SYSFS. There
is no point of keeping statistics if no one can restrive them.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Move the definition of kmalloc_caches_dma() into a later #ifdef CONFIG_ZONE_DMA.
This saves one #ifdef and leaves us with a total of two #ifdefs for dma slab support.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
As spotted by kmemcheck, we need to initialize the per-CPU ->stat array before
using it.
[kmem_cache_cpu structures are usually allocated from arrays defined via
DEFINE_PER_CPU that are zeroed so we have not noticed this so far --cl].
Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
This should be N_NORMAL_MEMORY.
N_NORMAL_MEMORY is "true" if a node has memory for the kernel. N_HIGH_MEMORY
is "true" if a node has memory for HIGHMEM. (If CONFIG_HIGHMEM=n, always
"true")
This check is used for testing whether we can use kmalloc_node() on a node.
Then, if there is a node which only contains HIGHMEM, the system will call
kmalloc_node() which doesn't contain memory for the kernel. If it happens
under SLUB, the kernel will panic. I think this only happens on x86_32-numa.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A boot option for the memory controller was discussed on lkml. It is a good
idea to add it, since it saves memory for people who want to turn off the
memory controller.
By default the option is on for the following two reasons:
1. It provides compatibility with the current scheme where the memory
controller turns on if the config option is enabled
2. It allows for wider testing of the memory controller, once the config
option is enabled
We still allow the create, destroy callbacks to succeed, since they are not
aware of boot options. We do not populate the directory will memory resource
controller specific files.
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Sudhir Kumar <skumar@linux.vnet.ibm.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Small typo in the patch recently merged to avoid the unused symbol
message for count_partial(). Discussion thread with confirmation of fix at
http://marc.info/?t=120696854400001&r=1&w=2
Typo in the check if we need the count_partial function that was
introduced by 53625b4204
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 3811dbf671.
The masking was not at all useless, and it was sensible. We handle
GFP_ZERO in the caller, and passing it down to any page allocator logic
is buggy and wrong.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Running the counters testcase from libhugetlbfs results in on 2.6.25-rc5
and 2.6.25-rc5-mm1:
BUG: soft lockup - CPU#3 stuck for 61s! [counters:10531]
NIP: c0000000000d1f3c LR: c0000000000d1f2c CTR: c0000000001b5088
REGS: c000005db12cb360 TRAP: 0901 Not tainted (2.6.25-rc5-autokern1)
MSR: 8000000000009032 <EE,ME,IR,DR> CR: 48008448 XER: 20000000
TASK = c000005dbf3d6000[10531] 'counters' THREAD: c000005db12c8000 CPU: 3
GPR00: 0000000000000004 c000005db12cb5e0 c000000000879228 0000000000000004
GPR04: 0000000000000010 0000000000000000 0000000000200200 0000000000100100
GPR08: c0000000008aba10 000000000000ffff 0000000000000004 0000000000000000
GPR12: 0000000028000442 c000000000770080
NIP [c0000000000d1f3c] .return_unused_surplus_pages+0x84/0x18c
LR [c0000000000d1f2c] .return_unused_surplus_pages+0x74/0x18c
Call Trace:
[c000005db12cb5e0] [c000005db12cb670] 0xc000005db12cb670 (unreliable)
[c000005db12cb670] [c0000000000d24c4] .hugetlb_acct_memory+0x2e0/0x354
[c000005db12cb740] [c0000000001b5048] .truncate_hugepages+0x1d4/0x214
[c000005db12cb890] [c0000000001b50a4] .hugetlbfs_delete_inode+0x1c/0x3c
[c000005db12cb920] [c000000000103fd8] .generic_delete_inode+0xf8/0x1c0
[c000005db12cb9b0] [c0000000001b5100] .hugetlbfs_drop_inode+0x3c/0x24c
[c000005db12cba50] [c00000000010287c] .iput+0xdc/0xf8
[c000005db12cbad0] [c0000000000fee54] .dentry_iput+0x12c/0x194
[c000005db12cbb60] [c0000000000ff050] .d_kill+0x6c/0xa4
[c000005db12cbbf0] [c0000000000ffb74] .dput+0x18c/0x1b0
[c000005db12cbc70] [c0000000000e9e98] .__fput+0x1a4/0x1e8
[c000005db12cbd10] [c0000000000e61ec] .filp_close+0xb8/0xe0
[c000005db12cbda0] [c0000000000e62d0] .sys_close+0xbc/0x134
[c000005db12cbe30] [c00000000000872c] syscall_exit+0x0/0x40
Instruction dump:
ebbe8038 38800010 e8bf0002 3bbd0008 7fa3eb78 38a50001 7ca507b4 4818df25
60000000 38800010 38a00000 7c601b78 <7fa3eb78> 2f800010 409d0008 38000010
This was tracked down to a potential livelock in
return_unused_surplus_hugepages(). In the case where we have surplus
pages on some node, but no free pages on the same node, we may never
break out of the loop. To avoid this livelock, terminate the search if
we iterate a number of times equal to the number of online nodes without
freeing a page.
Thanks to Andy Whitcroft and Adam Litke for helping with debugging and
the patch.
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently we show the surplus hugetlb pool state in /proc/meminfo, but
not in the per-node meminfo files, even though we track the information
on a per-node basis. Printing it there can help track down dynamic pool
bugs including the one in the follow-on patch.
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 556a169dab ("slab: fix bootstrap on
memoryless node") introduced bootstrap-time cache_cache list3s for all nodes
but forgot that initkmem_list3 needs to be accessed by [somevalue + node]. This
patch fixes list_add() corruption in mm/slab.c seen on the ES7000.
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Olaf Hering <olaf@aepfle.de>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Dan Yeisley <dan.yeisley@unisys.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Avoid warnings about unused functions if neither SLUB_DEBUG nor CONFIG_SLABINFO
is defined. This patch will be reversed when slab defrag is merged since slab
defrag requires count_partial() to determine the fragmentation status of
slab caches.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
[PATCH] get stack footprint of pathname resolution back to relative sanity
[PATCH] double iput() on failure exit in hugetlb
[PATCH] double dput() on failure exit in tiny-shmem
[PATCH] fix up new filp allocators
[PATCH] check for null vfsmount in dentry_open()
[PATCH] reiserfs: eliminate private use of struct file in xattr
[PATCH] sanitize hppfs
hppfs pass vfsmount to dentry_open()
[PATCH] restore export of do_kern_mount()
Revert commit f1a9ee758d:
Author: Rik van Riel <riel@redhat.com>
Date: Thu Feb 7 00:14:08 2008 -0800
kswapd should only wait on IO if there is IO
The current kswapd (and try_to_free_pages) code has an oddity where the
code will wait on IO, even if there is no IO in flight. This problem is
notable especially when the system scans through many unfreeable pages,
causing unnecessary stalls in the VM.
Additionally, tasks without __GFP_FS or __GFP_IO in the direct reclaim path
will sleep if a significant number of pages are encountered that should be
written out. This gives kswapd a chance to write out those pages, while
the direct reclaim task sleeps.
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Because of large latencies and interactivity problems reported by Carlos,
here: http://lkml.org/lkml/2008/3/22/211
Cc: Rik van Riel <riel@redhat.com>
Cc: "Carlos R. Mafra" <crmafra2@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With numa enabled, some callers could have a range of memory on one node
but try to free that on other node. This can cause some pages to be
freed wrongly.
For example: when we try to allocate 128g boot ram early for
gart/swiotlb, and free that range later so gart/swiotlb can get some
range afterwards.
With this patch, we don't need to care which node holds the range, just
loop to call free_bootmem_node for all online nodes.
This patch makes free_bootmem_core() more robust by trimming the sidx
and eidx according the ram range that the node has.
And make the free_bootmem_core handle this out of range case. We could
use bdata_list to make sure the range can be freed for sure. So next
time, we don't need to loop online nodes and could use free_bootmem
directly.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Tested-by: Ingo Molnar <mingo@elte.hu>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix kernel-doc notation in mm/readahead.c.
Change ":" to ";" so that it doesn't get treated as a doc section heading.
Move the comment block ending "*/" to a line by itself so that the text on
that last line is not lost (dropped).
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The check t->pid == t->pid is not the blessed way to check whether a task is a
group leader.
This is not about the code beautifulness only, but about pid namespaces fixes
- both the tgid and the pid fields on the task_struct are (slowly :( )
becoming deprecated.
Besides, the thread_group_leader() macro makes only one dereference :)
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Correct kernel-doc function names and parameters in rmap.c.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Convert tiny-shmem.c function comments to kernel-doc. Add parameters and
convert/fix other kernel-doc in shmem.c.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix various kernel-doc notation in mm/:
filemap.c: add function short description; convert 2 to kernel-doc
fremap.c: change parameter 'prot' to @prot
pagewalk.c: change "-" in function parameters to ":"
slab.c: fix short description of kmem_ptr_validate()
swap.c: fix description & parameters of put_pages_list()
swap_state.c: fix function parameters
vmalloc.c: change "@returns" to "Returns:" since that is not a parameter
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The fallback path needs to enable interrupts like done for
the other page allocator calls. This was not necessary with
the alternate fast path since we handled irq enable/disable in
the slow path. The regular fastpath handles irq enable/disable
around calls to the slow path so we need to restore the proper
status before calling the page allocator from the slowpath.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
iov_iter_advance() skips over zero-length iovecs, however it does not properly
terminate at the end of the iovec array. Fix this by checking against
i->count before we skip a zero-length iov.
The bug was reproduced with a test program that continually randomly creates
iovs to writev. The fix was also verified with the same program and also it
could verify that the correct data was contained in the file after each
writev.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Tested-by: "Kevin Coffman" <kwc@citi.umich.edu>
Cc: "Alexey Dobriyan" <adobriyan@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Free pages in the hugetlb pool are free and as such have a reference count of
zero. Regular allocations into the pool from the buddy are "freed" into the
pool which results in their page_count dropping to zero. However, surplus
pages can be directly utilized by the caller without first being freed to the
pool. Therefore, a call to put_page_testzero() is in order so that such a
page will be handed to the caller with a correct count.
This has not affected end users because the bad page count is reset before the
page is handed off. However, under CONFIG_DEBUG_VM this triggers a BUG when
the page count is validated.
Thanks go to Mel for first spotting this issue and providing an initial fix.
Signed-off-by: Adam Litke <agl@us.ibm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Address 3 known bugs in the current memory policy reference counting method.
I have a series of patches to rework the reference counting to reduce overhead
in the allocation path. However, that series will require testing in -mm once
I repost it.
1) alloc_page_vma() does not release the extra reference taken for
vma/shared mempolicy when the mode == MPOL_INTERLEAVE. This can result in
leaking mempolicy structures. This is probably occurring, but not being
noticed.
Fix: add the conditional release of the reference.
2) hugezonelist unconditionally releases a reference on the mempolicy when
mode == MPOL_INTERLEAVE. This can result in decrementing the reference
count for system default policy [should have no ill effect] or premature
freeing of task policy. If this occurred, the next allocation using task
mempolicy would use the freed structure and probably BUG out.
Fix: add the necessary check to the release.
3) The current reference counting method assumes that vma 'get_policy()'
methods automatically add an extra reference a non-NULL returned mempolicy.
This is true for shmem_get_policy() used by tmpfs mappings, including
regular page shm segments. However, SHM_HUGETLB shm's, backed by
hugetlbfs, just use the vma policy without the extra reference. This
results in freeing of the vma policy on the first allocation, with reuse of
the freed mempolicy structure on subsequent allocations.
Fix: Rather than add another condition to the conditional reference
release, which occur in the allocation path, just add a reference when
returning the vma policy in shm_get_policy() to match the assumptions.
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Greg KH <greg@kroah.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: David Rientjes <rientjes@google.com>
Cc: <eric.whitney@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
NUMA slab allocator cpu migration bugfix
The NUMA slab allocator (specifically, cache_alloc_refill)
is not refreshing its local copies of what cpu and what
numa node it is on, when it drops and reacquires the irq
block that it inherited from its caller. As a result
those values become invalid if an attempt to migrate the
process to another numa node occured while the irq block
had been dropped.
The solution is to make cache_alloc_refill reload these
variables whenever it drops and reacquires the irq block.
The error is very difficult to hit. When it does occur,
one gets the following oops + stack traceback bits in
check_spinlock_acquired:
kernel BUG at mm/slab.c:2417
cache_alloc_refill+0xe6
kmem_cache_alloc+0xd0
...
This patch was developed against 2.6.23, ported to and
compiled-tested only against 2.6.25-rc4.
Signed-off-by: Joe Korty <joe.korty@ccur.com>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
SLUB should pack even small objects nicely into cachelines if that is what
has been asked for. Use the same algorithm as SLAB for this.
The effect of this patch for a system with a cacheline size of 64
bytes is that the 24 byte sized slab caches will now put exactly
2 objects into a cacheline instead of 3 with some overlap into
the next cacheline. This reduces the object density in a 4k slab
from 170 to 128 objects (same as SLAB).
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Make them all use angle brackets and the directory name.
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
The NUMA fallback logic should be passing local_flags to kmem_get_pages() and not simply the
flags passed in.
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
The remote frees are in the freelist of the page and not in the
percpu freelist.
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Adam Litke noticed that currently we grow the hugepage pool independent of any
cpuset the running process may be in, but when shrinking the pool, the cpuset
is checked. This leads to inconsistency when shrinking the pool in a
restricted cpuset -- an administrator may have been able to grow the pool on a
node restricted by a containing cpuset, but they cannot shrink it there.
There are two options: either prevent growing of the pool outside of the
cpuset or allow shrinking outside of the cpuset. >From previous discussions
on linux-mm, /proc/sys/vm/nr_hugepages is an administrative interface that
should not be restricted by cpusets. So allow shrinking the pool by removing
pages from nodes outside of current's cpuset.
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Acked-by: Adam Litke <agl@us.ibm.com>
Cc: William Irwin <wli@holomorphy.com>
Cc: Lee Schermerhorn <Lee.Schermerhonr@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A hugetlb reservation may be inadequately backed in the event of racing
allocations and frees when utilizing surplus huge pages. Consider the
following series of events in processes A and B:
A) Allocates some surplus pages to satisfy a reservation
B) Frees some huge pages
A) A notices the extra free pages and drops hugetlb_lock to free some of
its surplus pages back to the buddy allocator.
B) Allocates some huge pages
A) Reacquires hugetlb_lock and returns from gather_surplus_huge_pages()
Avoid this by commiting the reservation after pages have been allocated but
before dropping the lock to free excess pages. For parity, release the
reservation in return_unused_surplus_pages().
This patch also corrects the cpuset_mems_nr() error path in
hugetlb_acct_memory(). If the cpuset check fails, uncommit the
reservation, but also be sure to return any surplus huge pages that may
have been allocated to back the failed reservation.
Thanks to Andy Whitcroft for discovering this.
Signed-off-by: Adam Litke <agl@us.ibm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While testing force_empty, during an exit_mmap, __mem_cgroup_remove_list
called from mem_cgroup_uncharge_page oopsed on a NULL pointer in the lru list.
I couldn't see what racing tasks on other cpus were doing, but surmise that
another must have been in mem_cgroup_charge_common on the same page, between
its unlock_page_cgroup and spin_lock_irqsave near done (thanks to that kzalloc
which I'd almost changed to a kmalloc).
Normally such a race cannot happen, the ref_cnt prevents it, the final
uncharge cannot race with the initial charge. But force_empty buggers the
ref_cnt, that's what it's all about; and thereafter forced pages are
vulnerable to races such as this (just think of a shared page also mapped into
an mm of another mem_cgroup than that just emptied). And remain vulnerable
until they're freed indefinitely later.
This patch just fixes the oops by moving the unlock_page_cgroups down below
adding to and removing from the list (only possible given the previous patch);
and while we're at it, we might as well make it an invariant that
page->page_cgroup is always set while pc is on lru.
But this behaviour of force_empty seems highly unsatisfactory to me: why have
a ref_cnt if we always have to cope with it being violated (as in the earlier
page migration patch). We may prefer force_empty to move pages to an orphan
mem_cgroup (could be the root, but better not), from which other cgroups could
recover them; we might need to reverse the locking again; but no time now for
such concerns.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As for force_empty, though this may not be the main topic here,
mem_cgroup_force_empty_list() can be implemented simpler. It is possible to
make the function just call mem_cgroup_uncharge_page() instead of releasing
page_cgroups by itself. The tip is to call get_page() before invoking
mem_cgroup_uncharge_page(), so the page won't be released during this
function.
Kamezawa-san points out that by the time mem_cgroup_uncharge_page() uncharges,
the page might have been reassigned to an lru of a different mem_cgroup, and
now be emptied from that; but Hugh claims that's okay, the end state is the
same as when it hasn't gone to another list.
And once force_empty stops taking lock_page_cgroup within mz->lru_lock,
mem_cgroup_move_lists() can be simplified to take mz->lru_lock directly while
holding page_cgroup lock (but still has to use try_lock_page_cgroup).
Signed-off-by: Hirokazu Takahashi <taka@valinux.co.jp>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ever since the VM_BUG_ON(page_get_page_cgroup(page)) (now Bad page state) went
into page freeing, I've hit it from time to time in testing on some machines,
sometimes only after many days. Recently found a machine which could usually
produce it within a few hours, which got me there at last.
The culprit is mem_cgroup_move_lists, whose locking is inadequate; and the
arrangement of structures was such that you got page_cgroups from the lru list
neatly put on to SLUB's freelist. Kamezawa-san identified the same hole
independently.
The main problem was that it was missing the lock_page_cgroup it needs to
safely page_get_page_cgroup; but it's tricky to go beyond that too, and I
couldn't do it with SLAB_DESTROY_BY_RCU as I'd expected. See the code for
comments on the constraints.
This patch immediately gets replaced by a simpler one from Hirokazu-san; but
is it just foolish pride that tells me to put this one on record, in case we
need to come back to it later?
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mem_cgroup_uncharge_page does css_put on the mem_cgroup before uncharging from
it, and before removing page_cgroup from one of its lru lists: isn't there a
danger that struct mem_cgroup memory could be freed and reused before
completing that, so corrupting something? Never seen it, and for all I know
there may be other constraints which make it impossible; but let's be
defensive and reverse the ordering there.
mem_cgroup_force_empty_list is safe because there's an extra css_get around
all its works; but even so, change its ordering the same way round, to help
get in the habit of doing it like this.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove clear_page_cgroup: it's an unhelpful helper, see for example how
mem_cgroup_uncharge_page had to unlock_page_cgroup just in order to call it
(serious races from that? I'm not sure).
Once that's gone, you can see it's pointless for page_cgroup's ref_cnt to be
atomic: it's always manipulated under lock_page_cgroup, except where
force_empty unilaterally reset it to 0 (and how does uncharge's
atomic_dec_and_test protect against that?).
Simplify this page_cgroup locking: if you've got the lock and the pc is
attached, then the ref_cnt must be positive: VM_BUG_ONs to check that, and to
check that pc->page matches page (we're on the way to finding why sometimes it
doesn't, but this patch doesn't fix that).
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
More cleanup to memcontrol.c, this time changing some of the code generated.
Let the compiler decide what to inline (except for page_cgroup_locked which is
only used when CONFIG_DEBUG_VM): the __always_inline on lock_page_cgroup etc.
was quite a waste since bit_spin_lock etc. are inlines in a header file; made
mem_cgroup_force_empty and mem_cgroup_write_strategy static.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sorry, before getting down to more important changes, I'd like to do some
cleanup in memcontrol.c. This patch doesn't change the code generated, but
cleans up whitespace, moves up a double declaration, removes an unused enum,
removes void returns, removes misleading comments, that kind of thing.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nothing uses mem_cgroup_uncharge apart from mem_cgroup_uncharge_page, (a
trivial wrapper around it) and mem_cgroup_end_migration (which does the same
as mem_cgroup_uncharge_page). And it often ends up having to lock just to let
its caller unlock. Remove it (but leave the silly locking until a later
patch).
Moved mem_cgroup_cache_charge next to mem_cgroup_charge in memcontrol.h.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: David Rientjes <rientjes@google.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
My memcgroup patch to fix hang with shmem/tmpfs added NULL page handling to
mem_cgroup_charge_common. It seemed convenient at the time, but hard to
justify now: there's a perfectly appropriate swappage to charge and uncharge
instead, this is not on any hot path through shmem_getpage, and no performance
hit was observed from the slight extra overhead.
So revert that NULL page handling from mem_cgroup_charge_common; and make it
clearer by bringing page_cgroup_assign_new_page_cgroup into its body - that
was a helper I found more of a hindrance to understanding.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: David Rientjes <rientjes@google.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace free_hot_cold_page's VM_BUG_ON(page_get_page_cgroup(page)) by a "Bad
page state" and clear: most users don't have CONFIG_DEBUG_VM on, and if it
were set here, it'd likely cause corruption when the page is reused.
Don't use page_assign_page_cgroup to clear it: that should be private to
memcontrol.c, and always called with the lock taken; and memmap_init_zone
doesn't need it either - like page->mapping and other pointers throughout the
kernel, Linux assumes pointers in zeroed structures are NULL pointers.
Instead use page_reset_bad_cgroup, added to memcontrol.h for this only.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: David Rientjes <rientjes@google.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Page migration gave me free_hot_cold_page's VM_BUG_ON page->page_cgroup.
remove_migration_pte was calling mem_cgroup_charge on the new page whenever it
found a swap pte, before it had determined it to be a migration entry. That
left a surplus reference count on the page_cgroup, so it was still attached
when the page was later freed.
Move that mem_cgroup_charge down to where we're sure it's a migration entry.
We were already under i_mmap_lock or anon_vma->lock, so its GFP_KERNEL was
already inappropriate: change that to GFP_ATOMIC.
It's essential that remove_migration_pte removes all the migration entries,
other crashes follow if not. So proceed even when the charge fails: normally
it cannot, but after a mem_cgroup_force_empty it might - comment in the code.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Don't uncharge when do_swap_page's call to do_wp_page fails: the page which
was charged for is there in the pagetable, and will be correctly uncharged
when that area is unmapped - it was only its COWing which failed.
And while we're here, remove earlier XXX comment: yes, OR in do_wp_page's
return value (maybe VM_FAULT_WRITE) with do_swap_page's there; but if it
fails, mask out success bits, which might confuse some arches e.g. sparc.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: David Rientjes <rientjes@google.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There's nothing wrong with mem_cgroup_charge failure in do_wp_page and
do_anonymous page using __free_page, but it does look odd when nearby code
uses page_cache_release: use that instead (while turning a blind eye to
ancient inconsistencies of page_cache_release versus put_page).
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: David Rientjes <rientjes@google.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Each caller of mem_cgroup_move_lists is having to use page_get_page_cgroup:
it's more convenient if it acts upon the page itself not the page_cgroup; and
in a later patch this becomes important to handle within memcontrol.c.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: David Rientjes <rientjes@google.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
vm_match_cgroup is a perverse name for a macro to match mm with cgroup: rename
it mm_match_cgroup, matching mm_init_cgroup and mm_free_cgroup.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rename Memory Controller to Memory Resource Controller. Reflect the same
changes in the CONFIG definition for the Memory Resource Controller. Group
together the config options for Resource Counters and Memory Resource
Controller.
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some oprofile results obtained while using tbench on a 2x2 cpu machine were
very surprising.
For example, loopback_xmit() function was using high number of cpu cycles
to perform the statistic updates, supposed to be real cheap since they use
percpu data
pcpu_lstats = netdev_priv(dev);
lb_stats = per_cpu_ptr(pcpu_lstats, smp_processor_id());
lb_stats->packets++; /* HERE : serious contention */
lb_stats->bytes += skb->len;
struct pcpu_lstats is a small structure containing two longs. It appears
that on my 32bits platform, alloc_percpu(8) allocates a single cache line,
instead of giving to each cpu a separate cache line.
Using the following patch gave me impressive boost in various benchmarks
( 6 % in tbench)
(all percpu_counters hit this bug too)
Long term fix (ie >= 2.6.26) would be to let each CPU allocate their own
block of memory, so that we dont need to roudup sizes to L1_CACHE_BYTES, or
merging the SGI stuff of course...
Note : SLUB vs SLAB is important here to *show* the improvement, since they
dont have the same minimum allocation sizes (8 bytes vs 32 bytes). This
could very well explain regressions some guys reported when they switched
to SLUB.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
jiffies subtraction may cause an overflow problem. It should be using
time_after().
[akpm@linux-foundation.org: include jiffies.h]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fix possible NULL pointer dereference if kzalloc
failed. To be able to return proper error code the function
return type is changed to ssize_t (according to callees and
sysfs definitions).
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Slub is missing some NUMA support for large kmallocs. Provide that.
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
We only need to look up object from c->page->freelist once in
__slab_alloc().
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Group SLUB_DEBUG code together to reduce the number of #ifdefs. Move some
debug checks under the #ifdef.
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
The BUG_ONs are useless since the pointer derefs will lead to
NULL deref errors anyways. Some of the checks are not necessary
if no debugging is possible.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
No need to access the kmem_cache structure. We have the same value
in kmem_cache_cpu.
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Alloc debug processing is never called with a NULL object pointer.
No reason to check for NULL.
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
There is no page->offset anymore and also no associated limit on the number
of objects. The page->offset field was removed for 2.6.24. So the check
in kmem_cache_flags() is now also obsolete (should have been dropped
earlier, somehow a hunk vanished).
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-by: Christoph Lameter <clameter@sgi.com>
The sysfs callback is better named show_slab_objects since it is always
called from the xxx_show callbacks. We need the name for other purposes
later.
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
This only made sense for the alternate fastpath which was reverted last week.
Mathieu is working on a new version that addresses the fastpath issues but that
new code first needs to go through mm and it is not clear if we need the
unique end pointers with his new scheme.
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Fix docbook problems in kernel-api.tmpl.
These cause the generated docbook to be incorrect.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cgroup requires the subsystem to return negative error code on error in the
create method.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove this VM_BUG_ON(), as Balbir stated:
We used to have a for loop with !list_empty() as a termination condition
and VM_BUG_ON(!pc) is a spill over. With the new loop, VM_BUG_ON(!pc) does
not make sense.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Balbir Singh <balbir@in.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
WARNING: vmlinux.o(.meminit.text+0x649):
Section mismatch in reference from the
function free_area_init_core() to the function .init.text:setup_usemap()
The function __meminit free_area_init_core() references
a function __init setup_usemap().
If free_area_init_core is only used by setup_usemap then
annotate free_area_init_core with a matching annotation.
The warning is covers this stack of functions in mm/page_alloc.c:
alloc_bootmem_node must be marked __init.
alloc_bootmem_node is used by setup_usemap, if !SPARSEMEM.
(usemap_size is only used by setup_usemap, if !SPARSEMEM.)
setup_usemap is only used by free_area_init_core.
free_area_init_core is only used by free_area_init_node.
free_area_init_node is used by:
arch/alpha/mm/numa.c: __init paging_init()
arch/arm/mm/init.c: __init bootmem_init_node()
arch/avr32/mm/init.c: __init paging_init()
arch/cris/arch-v10/mm/init.c: __init paging_init()
arch/cris/arch-v32/mm/init.c: __init paging_init()
arch/m32r/mm/discontig.c: __init zone_sizes_init()
arch/m32r/mm/init.c: __init zone_sizes_init()
arch/m68k/mm/motorola.c: __init paging_init()
arch/m68k/mm/sun3mmu.c: __init paging_init()
arch/mips/sgi-ip27/ip27-memory.c: __init paging_init()
arch/parisc/mm/init.c: __init paging_init()
arch/sparc/mm/srmmu.c: __init srmmu_paging_init()
arch/sparc/mm/sun4c.c: __init sun4c_paging_init()
arch/sparc64/mm/init.c: __init paging_init()
mm/page_alloc.c: __init free_area_init_nodes()
mm/page_alloc.c: __init free_area_init()
and
mm/memory_hotplug.c: hotadd_new_pgdat()
hotadd_new_pgdat can not be an __init function, but:
It is compiled for MEMORY_HOTPLUG configurations only
MEMORY_HOTPLUG depends on SPARSEMEM || X86_64_ACPI_NUMA
X86_64_ACPI_NUMA depends on X86_64
ARCH_FLATMEM_ENABLE depends on X86_32
ARCH_DISCONTIGMEM_ENABLE depends on X86_32
So X86_64_ACPI_NUMA implies SPARSEMEM, right?
So we can mark the stack of functions __init for !SPARSEMEM, but we must mark
them __meminit for SPARSEMEM configurations. This is ok, because then the
calls to alloc_bootmem_node are also avoided.
Compile-tested on:
silly minimal config
defconfig x86_32
defconfig x86_64
defconfig x86_64 -HIBERNATION +MEMORY_HOTPLUG
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When we free a page via free_huge_page and we detect that we are in surplus
the page will be returned to the buddy. After this we no longer own the page.
However at the end free_huge_page we clear out our mapping pointer from
page private. Even where the page is not a surplus we free the page to
the hugepage pool, drop the pool locks and then clear page private. In
either case the page may have been reallocated. BAD.
Make sure we clear out page private before we free the page.
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Acked-by: Adam Litke <agl@us.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 1f84260c8c, which is
suspected to be the reason for some very occasional and hard-to-trigger
crashes that usually look related to memory allocation (mostly reported
in networking, but since that's generally the most common source of
shortlived allocations - and allocations in interrupt contexts - that in
itself is not a big clue).
See for example
http://bugzilla.kernel.org/show_bug.cgi?id=9973http://lkml.org/lkml/2008/2/19/278
etc.
One promising suspicion for what the root cause of bug is (which also
explains why it's so hard to trigger in practice) came from Eric
Dumazet:
"I wonder how SLUB_FASTPATH is supposed to work, since it is affected
by a classical ABA problem of lockless algo.
cmpxchg_local(&c->freelist, object, object[c->offset]) can succeed,
while an interrupt came (on this cpu), and several allocations were
done, and one free was performed at the end of this interruption, so
'object' was recycled.
c->freelist can then contain the previous value (object), but
object[c->offset] was changed by IRQ.
We then put back in freelist an already allocated object."
but another reason for the revert is simply that everybody agrees that
this code was the main suspect just by virtue of the pattern of oopses.
Cc: Torsten Kaiser <just.for.lkml@googlemail.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'slab-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/christoph/vm:
slub: Support 4k kmallocs again to compensate for page allocator slowness
slub: Fallback to kmalloc_large for failing higher order allocs
slub: Determine gfpflags once and not every time a slab is allocated
make slub.c:slab_address() static
slub: kmalloc page allocator pass-through cleanup
slab: avoid double initialization & do initialization in 1 place
* git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86:
x86: cpa, fix out of date comment
KVM is not seen under X86 config with latest git (32 bit compile)
x86: cpa: ensure page alignment
x86: include proper prototypes for rodata_test
x86: fix gart_iommu_init()
x86: EFI set_memory_x()/set_memory_uc() fixes
x86: make dump_pagetable() static
x86: fix "BUG: sleeping function called from invalid context" in print_vma_addr()
d_path() is used on a <dentry,vfsmount> pair. Lets use a struct path to
reflect this.
[akpm@linux-foundation.org: fix build in mm/memory.c]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Acked-by: Bryan Wu <bryan.wu@analog.com>
Acked-by: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
seq_path() is always called with a dentry and a vfsmount from a struct path.
Make seq_path() take it directly as an argument.
Signed-off-by: Jan Blunck <jblunck@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently we hand off PAGE_SIZEd kmallocs to the page allocator in the
mistaken belief that the page allocator can handle these allocations
effectively. However, measurements indicate a minimum slowdown by the
factor of 8 (and that is only SMP, NUMA is much worse) vs the slub fastpath
which causes regressions in tbench.
Increase the number of kmalloc caches by one so that we again handle 4k
kmallocs directly from slub. 4k page buffering for the page allocator
will be performed by slub like done by slab.
At some point the page allocator fastpath should be fixed. A lot of the kernel
would benefit from a faster ability to allocate a single page. If that is
done then the 4k allocs may again be forwarded to the page allocator and this
patch could be reverted.
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Slub already has two ways of allocating an object. One is via its own
logic and the other is via the call to kmalloc_large to hand off object
allocation to the page allocator. kmalloc_large is typically used
for objects >= PAGE_SIZE.
We can use that handoff to avoid failing if a higher order kmalloc slab
allocation cannot be satisfied by the page allocator. If we reach the
out of memory path then simply try a kmalloc_large(). kfree() can
already handle the case of an object that was allocated via the page
allocator and so this will work just fine (apart from object
accounting...).
For any kmalloc slab that already requires higher order allocs (which
makes it impossible to use the page allocator fastpath!)
we just use PAGE_ALLOC_COSTLY_ORDER to get the largest number of
objects in one go from the page allocator slowpath.
On a 4k platform this patch will lead to the following use of higher
order pages for the following kmalloc slabs:
8 ... 1024 order 0
2048 .. 4096 order 3 (4k slab only after the next patch)
We may waste some space if fallback occurs on a 2k slab but we
are always able to fallback to an order 0 alloc.
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Currently we determine the gfp flags to pass to the page allocator
each time a slab is being allocated.
Determine the bits to be set at the time the slab is created. Store
in a new allocflags field and add the flags in allocate_slab().
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
This adds a proper function for kmalloc page allocator pass-through. While it
simplifies any code that does slab tracing code a lot, I think it's a
worthwhile cleanup in itself.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
