Commit Graph

4091 Commits

Author SHA1 Message Date
Mel Gorman
67b9509b2c mm: migration: do not try to migrate unmapped anonymous pages
rmap_walk_anon() was triggering errors in memory compaction that look like
use-after-free errors.  The problem is that between the page being
isolated from the LRU and rcu_read_lock() being taken, the mapcount of the
page dropped to 0 and the anon_vma gets freed.  This can happen during
memory compaction if pages being migrated belong to a process that exits
before migration completes.  Hence, the use-after-free race looks like

 1. Page isolated for migration
 2. Process exits
 3. page_mapcount(page) drops to zero so anon_vma was no longer reliable
 4. unmap_and_move() takes the rcu_lock but the anon_vma is already garbage
 4. call try_to_unmap, looks up tha anon_vma and "locks" it but the lock
    is garbage.

This patch checks the mapcount after the rcu lock is taken.  If the
mapcount is zero, the anon_vma is assumed to be freed and no further
action is taken.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:58 -07:00
Mel Gorman
7f60c214fd mm: migration: share the anon_vma ref counts between KSM and page migration
For clarity of review, KSM and page migration have separate refcounts on
the anon_vma.  While clear, this is a waste of memory.  This patch gets
KSM and page migration to share their toys in a spirit of harmony.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:58 -07:00
Mel Gorman
3f6c82728f mm: migration: take a reference to the anon_vma before migrating
This patchset is a memory compaction mechanism that reduces external
fragmentation memory by moving GFP_MOVABLE pages to a fewer number of
pageblocks.  The term "compaction" was chosen as there are is a number of
mechanisms that are not mutually exclusive that can be used to defragment
memory.  For example, lumpy reclaim is a form of defragmentation as was
slub "defragmentation" (really a form of targeted reclaim).  Hence, this
is called "compaction" to distinguish it from other forms of
defragmentation.

In this implementation, a full compaction run involves two scanners
operating within a zone - a migration and a free scanner.  The migration
scanner starts at the beginning of a zone and finds all movable pages
within one pageblock_nr_pages-sized area and isolates them on a
migratepages list.  The free scanner begins at the end of the zone and
searches on a per-area basis for enough free pages to migrate all the
pages on the migratepages list.  As each area is respectively migrated or
exhausted of free pages, the scanners are advanced one area.  A compaction
run completes within a zone when the two scanners meet.

This method is a bit primitive but is easy to understand and greater
sophistication would require maintenance of counters on a per-pageblock
basis.  This would have a big impact on allocator fast-paths to improve
compaction which is a poor trade-off.

It also does not try relocate virtually contiguous pages to be physically
contiguous.  However, assuming transparent hugepages were in use, a
hypothetical khugepaged might reuse compaction code to isolate free pages,
split them and relocate userspace pages for promotion.

Memory compaction can be triggered in one of three ways.  It may be
triggered explicitly by writing any value to /proc/sys/vm/compact_memory
and compacting all of memory.  It can be triggered on a per-node basis by
writing any value to /sys/devices/system/node/nodeN/compact where N is the
node ID to be compacted.  When a process fails to allocate a high-order
page, it may compact memory in an attempt to satisfy the allocation
instead of entering direct reclaim.  Explicit compaction does not finish
until the two scanners meet and direct compaction ends if a suitable page
becomes available that would meet watermarks.

The series is in 14 patches.  The first three are not "core" to the series
but are important pre-requisites.

Patch 1 reference counts anon_vma for rmap_walk_anon(). Without this
	patch, it's possible to use anon_vma after free if the caller is
	not holding a VMA or mmap_sem for the pages in question. While
	there should be no existing user that causes this problem,
	it's a requirement for memory compaction to be stable. The patch
	is at the start of the series for bisection reasons.
Patch 2 merges the KSM and migrate counts. It could be merged with patch 1
	but would be slightly harder to review.
Patch 3 skips over unmapped anon pages during migration as there are no
	guarantees about the anon_vma existing. There is a window between
	when a page was isolated and migration started during which anon_vma
	could disappear.
Patch 4 notes that PageSwapCache pages can still be migrated even if they
	are unmapped.
Patch 5 allows CONFIG_MIGRATION to be set without CONFIG_NUMA
Patch 6 exports a "unusable free space index" via debugfs. It's
	a measure of external fragmentation that takes the size of the
	allocation request into account. It can also be calculated from
	userspace so can be dropped if requested
Patch 7 exports a "fragmentation index" which only has meaning when an
	allocation request fails. It determines if an allocation failure
	would be due to a lack of memory or external fragmentation.
Patch 8 moves the definition for LRU isolation modes for use by compaction
Patch 9 is the compaction mechanism although it's unreachable at this point
Patch 10 adds a means of compacting all of memory with a proc trgger
Patch 11 adds a means of compacting a specific node with a sysfs trigger
Patch 12 adds "direct compaction" before "direct reclaim" if it is
	determined there is a good chance of success.
Patch 13 adds a sysctl that allows tuning of the threshold at which the
	kernel will compact or direct reclaim
Patch 14 temporarily disables compaction if an allocation failure occurs
	after compaction.

Testing of compaction was in three stages.  For the test, debugging,
preempt, the sleep watchdog and lockdep were all enabled but nothing nasty
popped out.  min_free_kbytes was tuned as recommended by hugeadm to help
fragmentation avoidance and high-order allocations.  It was tested on X86,
X86-64 and PPC64.

Ths first test represents one of the easiest cases that can be faced for
lumpy reclaim or memory compaction.

1. Machine freshly booted and configured for hugepage usage with
	a) hugeadm --create-global-mounts
	b) hugeadm --pool-pages-max DEFAULT:8G
	c) hugeadm --set-recommended-min_free_kbytes
	d) hugeadm --set-recommended-shmmax

	The min_free_kbytes here is important. Anti-fragmentation works best
	when pageblocks don't mix. hugeadm knows how to calculate a value that
	will significantly reduce the worst of external-fragmentation-related
	events as reported by the mm_page_alloc_extfrag tracepoint.

2. Load up memory
	a) Start updatedb
	b) Create in parallel a X files of pagesize*128 in size. Wait
	   until files are created. By parallel, I mean that 4096 instances
	   of dd were launched, one after the other using &. The crude
	   objective being to mix filesystem metadata allocations with
	   the buffer cache.
	c) Delete every second file so that pageblocks are likely to
	   have holes
	d) kill updatedb if it's still running

	At this point, the system is quiet, memory is full but it's full with
	clean filesystem metadata and clean buffer cache that is unmapped.
	This is readily migrated or discarded so you'd expect lumpy reclaim
	to have no significant advantage over compaction but this is at
	the POC stage.

3. In increments, attempt to allocate 5% of memory as hugepages.
	   Measure how long it took, how successful it was, how many
	   direct reclaims took place and how how many compactions. Note
	   the compaction figures might not fully add up as compactions
	   can take place for orders other than the hugepage size

X86				vanilla		compaction
Final page count                    913                916 (attempted 1002)
pages reclaimed                   68296               9791

X86-64				vanilla		compaction
Final page count:                   901                902 (attempted 1002)
Total pages reclaimed:           112599              53234

PPC64				vanilla		compaction
Final page count:                    93                 94 (attempted 110)
Total pages reclaimed:           103216              61838

There was not a dramatic improvement in success rates but it wouldn't be
expected in this case either.  What was important is that fewer pages were
reclaimed in all cases reducing the amount of IO required to satisfy a
huge page allocation.

The second tests were all performance related - kernbench, netperf, iozone
and sysbench.  None showed anything too remarkable.

The last test was a high-order allocation stress test.  Many kernel
compiles are started to fill memory with a pressured mix of unmovable and
movable allocations.  During this, an attempt is made to allocate 90% of
memory as huge pages - one at a time with small delays between attempts to
avoid flooding the IO queue.

                                             vanilla   compaction
Percentage of request allocated X86               98           99
Percentage of request allocated X86-64            95           98
Percentage of request allocated PPC64             55           70

This patch:

rmap_walk_anon() does not use page_lock_anon_vma() for looking up and
locking an anon_vma and it does not appear to have sufficient locking to
ensure the anon_vma does not disappear from under it.

This patch copies an approach used by KSM to take a reference on the
anon_vma while pages are being migrated.  This should prevent rmap_walk()
running into nasty surprises later because anon_vma has been freed.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: 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>
2010-05-25 08:06:58 -07:00
David Rientjes
e325c90ffc mm: default to node zonelist ordering when nodes have only lowmem
There are two types of zonelist ordering methodologies:

 - node order, preferring allocations on a node to stay local to and

 - zone order, preferring allocations come from a higher zone to avoid
   allocating in lowmem zones even though they may not be local.

The ordering technique used by the kernel is configurable on the command
line, but also has some logic to determine what the default should be.

This logic currently lacks knowledge of systems where a node may only have
lowmem.  For such systems, it is necessary to use node order so that
GFP_KERNEL allocations may be satisfied by nodes consisting of only
lowmem.

If zone order is used, GFP_KERNEL allocations to such nodes are actually
allocated on a node with local affinity that includes ZONE_NORMAL.

This change defaults to node zonelist ordering if any node lacks
ZONE_NORMAL.

To force zone order, append 'numa_zonelist_order=zone' to the kernel
command line.

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: 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>
2010-05-25 08:06:58 -07:00
Johannes Weiner
e48293fd75 mincore: do nested page table walks
Do page table walks with the well-known nested loops we use in several
other places already.

This avoids doing full page table walks after every pte range and also
allows to handle unmapped areas bigger than one pte range in one go.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:58 -07:00
Johannes Weiner
25ef0e50cc mincore: pass ranges as start,end address pairs
Instead of passing a start address and a number of pages into the helper
functions, convert them to use a start and an end address.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:58 -07:00
Johannes Weiner
f488401076 mincore: break do_mincore() into logical pieces
Split out functions to handle hugetlb ranges, pte ranges and unmapped
ranges, to improve readability but also to prepare the file structure for
nested page table walks.

No semantic changes intended.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:58 -07:00
Johannes Weiner
6a60f1b358 mincore: cleanups
This fixes some minor issues that bugged me while going over the code:

o adjust argument order of do_mincore() to match the syscall
o simplify range length calculation
o drop superfluous shift in huge tlb calculation, address is page aligned
o drop dead nr_huge calculation
o check pte_none() before pte_present()
o comment and whitespace fixes

No semantic changes intended.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:58 -07:00
Miao Xie
c0ff7453bb cpuset,mm: fix no node to alloc memory when changing cpuset's mems
Before applying this patch, cpuset updates task->mems_allowed and
mempolicy by setting all new bits in the nodemask first, and clearing all
old unallowed bits later.  But in the way, the allocator may find that
there is no node to alloc memory.

The reason is that cpuset rebinds the task's mempolicy, it cleans the
nodes which the allocater can alloc pages on, for example:

(mpol: mempolicy)
	task1			task1's mpol	task2
	alloc page		1
	  alloc on node0? NO	1
				1		change mems from 1 to 0
				1		rebind task1's mpol
				0-1		  set new bits
				0	  	  clear disallowed bits
	  alloc on node1? NO	0
	  ...
	can't alloc page
	  goto oom

This patch fixes this problem by expanding the nodes range first(set newly
allowed bits) and shrink it lazily(clear newly disallowed bits).  So we
use a variable to tell the write-side task that read-side task is reading
nodemask, and the write-side task clears newly disallowed nodes after
read-side task ends the current memory allocation.

[akpm@linux-foundation.org: fix spello]
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Paul Menage <menage@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:57 -07:00
Miao Xie
708c1bbc9d mempolicy: restructure rebinding-mempolicy functions
Nick Piggin reported that the allocator may see an empty nodemask when
changing cpuset's mems[1].  It happens only on the kernel that do not do
atomic nodemask_t stores.  (MAX_NUMNODES > BITS_PER_LONG)

But I found that there is also a problem on the kernel that can do atomic
nodemask_t stores.  The problem is that the allocator can't find a node to
alloc page when changing cpuset's mems though there is a lot of free
memory.  The reason is like this:

(mpol: mempolicy)
	task1			task1's mpol	task2
	alloc page		1
	  alloc on node0? NO	1
				1		change mems from 1 to 0
				1		rebind task1's mpol
				0-1		  set new bits
				0	  	  clear disallowed bits
	  alloc on node1? NO	0
	  ...
	can't alloc page
	  goto oom

I can use the attached program reproduce it by the following step:

# mkdir /dev/cpuset
# mount -t cpuset cpuset /dev/cpuset
# mkdir /dev/cpuset/1
# echo `cat /dev/cpuset/cpus` > /dev/cpuset/1/cpus
# echo `cat /dev/cpuset/mems` > /dev/cpuset/1/mems
# echo $$ > /dev/cpuset/1/tasks
# numactl --membind=`cat /dev/cpuset/mems` ./cpuset_mem_hog <nr_tasks> &
   <nr_tasks> = max(nr_cpus - 1, 1)
# killall -s SIGUSR1 cpuset_mem_hog
# ./change_mems.sh

several hours later, oom will happen though there is a lot of free memory.

This patchset fixes this problem by expanding the nodes range first(set
newly allowed bits) and shrink it lazily(clear newly disallowed bits).  So
we use a variable to tell the write-side task that read-side task is
reading nodemask, and the write-side task clears newly disallowed nodes
after read-side task ends the current memory allocation.

This patch:

In order to fix no node to alloc memory, when we want to update mempolicy
and mems_allowed, we expand the set of nodes first (set all the newly
nodes) and shrink the set of nodes lazily(clean disallowed nodes), But the
mempolicy's rebind functions may breaks the expanding.

So we restructure the mempolicy's rebind functions and split the rebind
work to two steps, just like the update of cpuset's mems: The 1st step:
expand the set of the mempolicy's nodes.  The 2nd step: shrink the set of
the mempolicy's nodes.  It is used when there is no real lock to protect
the mempolicy in the read-side.  Otherwise we can do rebind work at once.

In order to implement it, we define

	enum mpol_rebind_step {
		MPOL_REBIND_ONCE,
		MPOL_REBIND_STEP1,
		MPOL_REBIND_STEP2,
		MPOL_REBIND_NSTEP,
	};

If the mempolicy needn't be updated by two steps, we can pass
MPOL_REBIND_ONCE to the rebind functions.  Or we can pass
MPOL_REBIND_STEP1 to do the first step of the rebind work and pass
MPOL_REBIND_STEP2 to do the second step work.

Besides that, it maybe long time between these two step and we have to
release the lock that protects mempolicy and mems_allowed.  If we hold the
lock once again, we must check whether the current mempolicy is under the
rebinding (the first step has been done) or not, because the task may
alloc a new mempolicy when we don't hold the lock.  So we defined the
following flag to identify it:

#define MPOL_F_REBINDING (1 << 2)

The new functions will be used in the next patch.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Paul Menage <menage@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:57 -07:00
Lee Schermerhorn
15d77835ac mempolicy: factor mpol_shared_policy_init() return paths
Factor out duplicate put/frees in mpol_shared_policy_init() to a common
return path.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:57 -07:00
Lee Schermerhorn
345ace9c79 mempolicy: rename policy_types and cleanup initialization
Rename 'policy_types[]' to 'policy_modes[]' to better match the array
contents.

Use designated intializer syntax for policy_modes[].

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:57 -07:00
Lee Schermerhorn
b4652e8429 mempolicy: lose unnecessary loop variable in mpol_parse_str()
We don't really need the extra variable 'i' in mpol_parse_str().  The only
use is as the the loop variable.  Then, it's assigned to 'mode'.  Just use
mode, and loose the 'uninitialized_var()' macro.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:57 -07:00
Lee Schermerhorn
e17f74af35 mempolicy: don't call mpol_set_nodemask() when no_context
No need to call mpol_set_nodemask() when we have no context for the
mempolicy.  This can occur when we're parsing a tmpfs 'mpol' mount option.
 Just save the raw nodemask in the mempolicy's w.user_nodemask member for
use when a tmpfs/shmem file is created.  mpol_shared_policy_init() will
"contextualize" the policy for the new file based on the creating task's
context.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:57 -07:00
Bob Liu
1980050250 mempolicy: remove redundant check
Lee's patch "mempolicy: use MPOL_PREFERRED for system-wide default policy"
has made the MPOL_DEFAULT only used in the memory policy APIs.  So, no
need to check in __mpol_equal also.  Also get rid of mpol_match_intent()
and move its logic directly into __mpol_equal().

Signed-off-by: Bob Liu <lliubbo@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:57 -07:00
Bob Liu
6eb27e1fdf mempolicy: remove case MPOL_INTERLEAVE from policy_zonelist()
In policy_zonelist() mode MPOL_INTERLEAVE shouldn't happen, so fall
through to BUG() instead of break to return.  I also fixed the comment.

Signed-off-by: Bob Liu <lliubbo@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:57 -07:00
Bob Liu
6d556294d5 mempolicy: remove redundant code
1.  In funtion is_valid_nodemask(), varibable k will be inited to 0 in
   the following loop, needn't init to policy_zone anymore.

2. (MPOL_F_STATIC_NODES | MPOL_F_RELATIVE_NODES) has already defined
   to MPOL_MODE_FLAGS in mempolicy.h.

Signed-off-by: Bob Liu <lliubbo@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
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>
2010-05-25 08:06:57 -07:00
Minchan Kim
e13861d822 mm: remove return value of putback_lru_pages()
putback_lru_page() never can fail.  So it doesn't matter count of "the
number of pages put back".

In addition, users of this functions don't use return value.

Let's remove unnecessary code.

Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-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>
2010-05-25 08:06:57 -07:00
Huang Shijie
4b50dc26a0 shmem: remove redundant code
prep_new_page() will call set_page_private(page, 0) to initialise the
page, so the code is redundant.

Signed-off-by: Huang Shijie <shijie8@gmail.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:57 -07:00
Yinghai Lu
e48e67e08c sparsemem: on no vmemmap path put mem_map on node high too
We need to put mem_map high when virtual memmap is not used.

before this patch
free mem pfn range on first node:
[    0.000000]  19 - 1f
[    0.000000]  28 40 - 80 95
[    0.000000]  702 740 - 1000 1000
[    0.000000]  347c - 347e
[    0.000000]  34e7 3500 - 3b80 3b8b
[    0.000000]  73b8b 73bc0 - 73c00 73c00
[    0.000000]  73ddd - 73e00
[    0.000000]  73fdd - 74000
[    0.000000]  741dd - 74200
[    0.000000]  743dd - 74400
[    0.000000]  745dd - 74600
[    0.000000]  747dd - 74800
[    0.000000]  749dd - 74a00
[    0.000000]  74bdd - 74c00
[    0.000000]  74ddd - 74e00
[    0.000000]  74fdd - 75000
[    0.000000]  751dd - 75200
[    0.000000]  753dd - 75400
[    0.000000]  755dd - 75600
[    0.000000]  757dd - 75800
[    0.000000]  759dd - 75a00
[    0.000000]  79bdd 79c00 - 7d540 7d550
[    0.000000]  7f745 - 7f750
[    0.000000]  10000b 100040 - 2080000 2080000
so only 79c00 - 7d540 are major free block under 4g...

after this patch, we will get
[    0.000000]  19 - 1f
[    0.000000]  28 40 - 80 95
[    0.000000]  702 740 - 1000 1000
[    0.000000]  347c - 347e
[    0.000000]  34e7 3500 - 3600 3600
[    0.000000]  37dd - 3800
[    0.000000]  39dd - 3a00
[    0.000000]  3bdd - 3c00
[    0.000000]  3ddd - 3e00
[    0.000000]  3fdd - 4000
[    0.000000]  41dd - 4200
[    0.000000]  43dd - 4400
[    0.000000]  45dd - 4600
[    0.000000]  47dd - 4800
[    0.000000]  49dd - 4a00
[    0.000000]  4bdd - 4c00
[    0.000000]  4ddd - 4e00
[    0.000000]  4fdd - 5000
[    0.000000]  51dd - 5200
[    0.000000]  53dd - 5400
[    0.000000]  95dd 9600 - 7d540 7d550
[    0.000000]  7f745 - 7f750
[    0.000000]  17000b 170040 - 2080000 2080000
we will have 9600 - 7d540 for major free block...

sparse-vmemmap path already used __alloc_bootmem_node_high()

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:56 -07:00
Corrado Zoccolo
6dda9d55bf page allocator: reduce fragmentation in buddy allocator by adding buddies that are merging to the tail of the free lists
In order to reduce fragmentation, this patch classifies freed pages in two
groups according to their probability of being part of a high order merge.
 Pages belonging to a compound whose next-highest buddy is free are more
likely to be part of a high order merge in the near future, so they will
be added at the tail of the freelist.  The remaining pages are put at the
front of the freelist.

In this way, the pages that are more likely to cause a big merge are kept
free longer.  Consequently there is a tendency to aggregate the
long-living allocations on a subset of the compounds, reducing the
fragmentation.

This heuristic was tested on three machines, x86, x86-64 and ppc64 with
3GB of RAM in each machine.  The tests were kernbench, netperf, sysbench
and STREAM for performance and a high-order stress test for huge page
allocations.

KernBench X86
Elapsed mean     374.77 ( 0.00%)   375.10 (-0.09%)
User    mean     649.53 ( 0.00%)   650.44 (-0.14%)
System  mean      54.75 ( 0.00%)    54.18 ( 1.05%)
CPU     mean     187.75 ( 0.00%)   187.25 ( 0.27%)

KernBench X86-64
Elapsed mean      94.45 ( 0.00%)    94.01 ( 0.47%)
User    mean     323.27 ( 0.00%)   322.66 ( 0.19%)
System  mean      36.71 ( 0.00%)    36.50 ( 0.57%)
CPU     mean     380.75 ( 0.00%)   381.75 (-0.26%)

KernBench PPC64
Elapsed mean     173.45 ( 0.00%)   173.74 (-0.17%)
User    mean     587.99 ( 0.00%)   587.95 ( 0.01%)
System  mean      60.60 ( 0.00%)    60.57 ( 0.05%)
CPU     mean     373.50 ( 0.00%)   372.75 ( 0.20%)

Nothing notable for kernbench.

NetPerf UDP X86
      64    42.68 ( 0.00%)     42.77 ( 0.21%)
     128    85.62 ( 0.00%)     85.32 (-0.35%)
     256   170.01 ( 0.00%)    168.76 (-0.74%)
    1024   655.68 ( 0.00%)    652.33 (-0.51%)
    2048  1262.39 ( 0.00%)   1248.61 (-1.10%)
    3312  1958.41 ( 0.00%)   1944.61 (-0.71%)
    4096  2345.63 ( 0.00%)   2318.83 (-1.16%)
    8192  4132.90 ( 0.00%)   4089.50 (-1.06%)
   16384  6770.88 ( 0.00%)   6642.05 (-1.94%)*

NetPerf UDP X86-64
      64   148.82 ( 0.00%)    154.92 ( 3.94%)
     128   298.96 ( 0.00%)    312.95 ( 4.47%)
     256   583.67 ( 0.00%)    626.39 ( 6.82%)
    1024  2293.18 ( 0.00%)   2371.10 ( 3.29%)
    2048  4274.16 ( 0.00%)   4396.83 ( 2.79%)
    3312  6356.94 ( 0.00%)   6571.35 ( 3.26%)
    4096  7422.68 ( 0.00%)   7635.42 ( 2.79%)*
    8192 12114.81 ( 0.00%)* 12346.88 ( 1.88%)
   16384 17022.28 ( 0.00%)* 17033.19 ( 0.06%)*
             1.64%             2.73%

NetPerf UDP PPC64
      64    49.98 ( 0.00%)     50.25 ( 0.54%)
     128    98.66 ( 0.00%)    100.95 ( 2.27%)
     256   197.33 ( 0.00%)    191.03 (-3.30%)
    1024   761.98 ( 0.00%)    785.07 ( 2.94%)
    2048  1493.50 ( 0.00%)   1510.85 ( 1.15%)
    3312  2303.95 ( 0.00%)   2271.72 (-1.42%)
    4096  2774.56 ( 0.00%)   2773.06 (-0.05%)
    8192  4918.31 ( 0.00%)   4793.59 (-2.60%)
   16384  7497.98 ( 0.00%)   7749.52 ( 3.25%)

The tests are run to have confidence limits within 1%.  Results marked
with a * were not confident although in this case, it's only outside by
small amounts.  Even with some results that were not confident, the
netperf UDP results were generally positive.

NetPerf TCP X86
      64   652.25 ( 0.00%)*   648.12 (-0.64%)*
            23.80%            22.82%
     128  1229.98 ( 0.00%)*  1220.56 (-0.77%)*
            21.03%            18.90%
     256  2105.88 ( 0.00%)   1872.03 (-12.49%)*
             1.00%            16.46%
    1024  3476.46 ( 0.00%)*  3548.28 ( 2.02%)*
            13.37%            11.39%
    2048  4023.44 ( 0.00%)*  4231.45 ( 4.92%)*
             9.76%            12.48%
    3312  4348.88 ( 0.00%)*  4396.96 ( 1.09%)*
             6.49%             8.75%
    4096  4726.56 ( 0.00%)*  4877.71 ( 3.10%)*
             9.85%             8.50%
    8192  4732.28 ( 0.00%)*  5777.77 (18.10%)*
             9.13%            13.04%
   16384  5543.05 ( 0.00%)*  5906.24 ( 6.15%)*
             7.73%             8.68%

NETPERF TCP X86-64
            netperf-tcp-vanilla-netperf       netperf-tcp
                   tcp-vanilla     pgalloc-delay
      64  1895.87 ( 0.00%)*  1775.07 (-6.81%)*
             5.79%             4.78%
     128  3571.03 ( 0.00%)*  3342.20 (-6.85%)*
             3.68%             6.06%
     256  5097.21 ( 0.00%)*  4859.43 (-4.89%)*
             3.02%             2.10%
    1024  8919.10 ( 0.00%)*  8892.49 (-0.30%)*
             5.89%             6.55%
    2048 10255.46 ( 0.00%)* 10449.39 ( 1.86%)*
             7.08%             7.44%
    3312 10839.90 ( 0.00%)* 10740.15 (-0.93%)*
             6.87%             7.33%
    4096 10814.84 ( 0.00%)* 10766.97 (-0.44%)*
             6.86%             8.18%
    8192 11606.89 ( 0.00%)* 11189.28 (-3.73%)*
             7.49%             5.55%
   16384 12554.88 ( 0.00%)* 12361.22 (-1.57%)*
             7.36%             6.49%

NETPERF TCP PPC64
            netperf-tcp-vanilla-netperf       netperf-tcp
                   tcp-vanilla     pgalloc-delay
      64   594.17 ( 0.00%)    596.04 ( 0.31%)*
             1.00%             2.29%
     128  1064.87 ( 0.00%)*  1074.77 ( 0.92%)*
             1.30%             1.40%
     256  1852.46 ( 0.00%)*  1856.95 ( 0.24%)
             1.25%             1.00%
    1024  3839.46 ( 0.00%)*  3813.05 (-0.69%)
             1.02%             1.00%
    2048  4885.04 ( 0.00%)*  4881.97 (-0.06%)*
             1.15%             1.04%
    3312  5506.90 ( 0.00%)   5459.72 (-0.86%)
    4096  6449.19 ( 0.00%)   6345.46 (-1.63%)
    8192  7501.17 ( 0.00%)   7508.79 ( 0.10%)
   16384  9618.65 ( 0.00%)   9490.10 (-1.35%)

There was a distinct lack of confidence in the X86* figures so I included
what the devation was where the results were not confident.  Many of the
results, whether gains or losses were within the standard deviation so no
solid conclusion can be reached on performance impact.  Looking at the
figures, only the X86-64 ones look suspicious with a few losses that were
outside the noise.  However, the results were so unstable that without
knowing why they vary so much, a solid conclusion cannot be reached.

SYSBENCH X86
              sysbench-vanilla     pgalloc-delay
           1  7722.85 ( 0.00%)  7756.79 ( 0.44%)
           2 14901.11 ( 0.00%) 13683.44 (-8.90%)
           3 15171.71 ( 0.00%) 14888.25 (-1.90%)
           4 14966.98 ( 0.00%) 15029.67 ( 0.42%)
           5 14370.47 ( 0.00%) 14865.00 ( 3.33%)
           6 14870.33 ( 0.00%) 14845.57 (-0.17%)
           7 14429.45 ( 0.00%) 14520.85 ( 0.63%)
           8 14354.35 ( 0.00%) 14362.31 ( 0.06%)

SYSBENCH X86-64
           1 17448.70 ( 0.00%) 17484.41 ( 0.20%)
           2 34276.39 ( 0.00%) 34251.00 (-0.07%)
           3 50805.25 ( 0.00%) 50854.80 ( 0.10%)
           4 66667.10 ( 0.00%) 66174.69 (-0.74%)
           5 66003.91 ( 0.00%) 65685.25 (-0.49%)
           6 64981.90 ( 0.00%) 65125.60 ( 0.22%)
           7 64933.16 ( 0.00%) 64379.23 (-0.86%)
           8 63353.30 ( 0.00%) 63281.22 (-0.11%)
           9 63511.84 ( 0.00%) 63570.37 ( 0.09%)
          10 62708.27 ( 0.00%) 63166.25 ( 0.73%)
          11 62092.81 ( 0.00%) 61787.75 (-0.49%)
          12 61330.11 ( 0.00%) 61036.34 (-0.48%)
          13 61438.37 ( 0.00%) 61994.47 ( 0.90%)
          14 62304.48 ( 0.00%) 62064.90 (-0.39%)
          15 63296.48 ( 0.00%) 62875.16 (-0.67%)
          16 63951.76 ( 0.00%) 63769.09 (-0.29%)

SYSBENCH PPC64
                             -sysbench-pgalloc-delay-sysbench
              sysbench-vanilla     pgalloc-delay
           1  7645.08 ( 0.00%)  7467.43 (-2.38%)
           2 14856.67 ( 0.00%) 14558.73 (-2.05%)
           3 21952.31 ( 0.00%) 21683.64 (-1.24%)
           4 27946.09 ( 0.00%) 28623.29 ( 2.37%)
           5 28045.11 ( 0.00%) 28143.69 ( 0.35%)
           6 27477.10 ( 0.00%) 27337.45 (-0.51%)
           7 26489.17 ( 0.00%) 26590.06 ( 0.38%)
           8 26642.91 ( 0.00%) 25274.33 (-5.41%)
           9 25137.27 ( 0.00%) 24810.06 (-1.32%)
          10 24451.99 ( 0.00%) 24275.85 (-0.73%)
          11 23262.20 ( 0.00%) 23674.88 ( 1.74%)
          12 24234.81 ( 0.00%) 23640.89 (-2.51%)
          13 24577.75 ( 0.00%) 24433.50 (-0.59%)
          14 25640.19 ( 0.00%) 25116.52 (-2.08%)
          15 26188.84 ( 0.00%) 26181.36 (-0.03%)
          16 26782.37 ( 0.00%) 26255.99 (-2.00%)

Again, there is little to conclude here.  While there are a few losses,
the results vary by +/- 8% in some cases.  They are the results of most
concern as there are some large losses but it's also within the variance
typically seen between kernel releases.

The STREAM results varied so little and are so verbose that I didn't
include them here.

The final test stressed how many huge pages can be allocated.  The
absolute number of huge pages allocated are the same with or without the
page.  However, the "unusability free space index" which is a measure of
external fragmentation was slightly lower (lower is better) throughout the
lifetime of the system.  I also measured the latency of how long it took
to successfully allocate a huge page.  The latency was slightly lower and
on X86 and PPC64, more huge pages were allocated almost immediately from
the free lists.  The improvement is slight but there.

[mel@csn.ul.ie: Tested, reworked for less branches]
[czoccolo@gmail.com: fix oops by checking pfn_valid_within()]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Corrado Zoccolo <czoccolo@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:56 -07:00
KOSAKI Motohiro
e9d6c15738 tmpfs: insert tmpfs cache pages to inactive list at first
Shaohua Li reported parallel file copy on tmpfs can lead to OOM killer.
This is regression of caused by commit 9ff473b9a7 ("vmscan: evict
streaming IO first").  Wow, It is 2 years old patch!

Currently, tmpfs file cache is inserted active list at first.  This means
that the insertion doesn't only increase numbers of pages in anon LRU, but
it also reduces anon scanning ratio.  Therefore, vmscan will get totally
confused.  It scans almost only file LRU even though the system has plenty
unused tmpfs pages.

Historically, lru_cache_add_active_anon() was used for two reasons.
1) Intend to priotize shmem page rather than regular file cache.
2) Intend to avoid reclaim priority inversion of used once pages.

But we've lost both motivation because (1) Now we have separate anon and
file LRU list.  then, to insert active list doesn't help such priotize.
(2) In past, one pte access bit will cause page activation.  then to
insert inactive list with pte access bit mean higher priority than to
insert active list.  Its priority inversion may lead to uninteded lru
chun.  but it was already solved by commit 645747462 (vmscan: detect
mapped file pages used only once).  (Thanks Hannes, you are great!)

Thus, now we can use lru_cache_add_anon() instead.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reported-by: Shaohua Li <shaohua.li@intel.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:56 -07:00
Josef Bacik
66f998f611 fs: allow short direct-io reads to be completed via buffered IO
This is similar to what already happens in the write case.  If we have a short
read while doing O_DIRECT, instead of just returning, fallthrough and try to
read the rest via buffered IO.  BTRFS needs this because if we encounter a
compressed or inline extent during DIO, we need to fallback on buffered.  If the
extent is compressed we need to read the entire thing into memory and
de-compress it into the users pages.  I have tested this with fsx and everything
works great.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25 10:34:55 -04:00
Miklos Szeredi
a52116aba5 mm: export remove_from_page_cache() to modules
This is needed to enable moving pages into the page cache in fuse with
splice(..., SPLICE_F_MOVE).

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2010-05-25 15:06:06 +02:00
Miklos Szeredi
47846b0650 mm: export lru_cache_add_*() to modules
This is needed to enable moving pages into the page cache in fuse with
splice(..., SPLICE_F_MOVE).

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2010-05-25 15:06:06 +02:00
Alexander Duyck
73367bd8ee slub: move kmem_cache_node into it's own cacheline
This patch is meant to improve the performance of SLUB by moving the local
kmem_cache_node lock into it's own cacheline separate from kmem_cache.
This is accomplished by simply removing the local_node when NUMA is enabled.

On my system with 2 nodes I saw around a 5% performance increase w/
hackbench times dropping from 6.2 seconds to 5.9 seconds on average.  I
suspect the performance gain would increase as the number of nodes
increases, but I do not have the data to currently back that up.

Bugzilla-Reference: http://bugzilla.kernel.org/show_bug.cgi?id=15713
Cc: <stable@kernel.org>
Reported-by: Alex Shi <alex.shi@intel.com>
Tested-by: Alex Shi <alex.shi@intel.com>
Acked-by: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-05-24 21:11:29 +03:00
Pekka Enberg
bb4f6b0cd7 Merge branches 'slab/align', 'slab/cleanups', 'slab/fixes', 'slab/memhotadd' and 'slub/fixes' into slab-for-linus 2010-05-22 10:57:52 +03:00
Minchan Kim
6b65aaf302 slub: Use alloc_pages_exact_node() for page allocation
The alloc_slab_page() in SLUB uses alloc_pages() if node is '-1'.  This means
that node validity check in alloc_pages_node is unnecessary and we can use
alloc_pages_exact_node() to avoid comparison and branch as commit
6484eb3e2a ("page allocator: do not check NUMA node ID when the caller
knows the node is valid") did for the page allocator.

Cc: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-05-22 10:57:31 +03:00
Xiaotian Feng
d3e14aa336 slub: __kmalloc_node_track_caller should trace kmalloc_large_node case
commit 94b528d (kmemtrace: SLUB hooks for caller-tracking functions)
missed tracing kmalloc_large_node in __kmalloc_node_track_caller. We
should trace it same as __kmalloc_node.

Acked-by: David Rientjes <rientjes@google.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-05-22 10:57:31 +03:00
Eric Dumazet
bbd7d57bfe slub: Potential stack overflow
I discovered that we can overflow stack if CONFIG_SLUB_DEBUG=y and use slabs
with many objects, since list_slab_objects() and process_slab() use
DECLARE_BITMAP(map, page->objects).

With 65535 bits, we use 8192 bytes of stack ...

Switch these allocations to dynamic allocations.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-05-22 10:57:30 +03:00
Linus Torvalds
e8bebe2f71 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (69 commits)
  fix handling of offsets in cris eeprom.c, get rid of fake on-stack files
  get rid of home-grown mutex in cris eeprom.c
  switch ecryptfs_write() to struct inode *, kill on-stack fake files
  switch ecryptfs_get_locked_page() to struct inode *
  simplify access to ecryptfs inodes in ->readpage() and friends
  AFS: Don't put struct file on the stack
  Ban ecryptfs over ecryptfs
  logfs: replace inode uid,gid,mode initialization with helper function
  ufs: replace inode uid,gid,mode initialization with helper function
  udf: replace inode uid,gid,mode init with helper
  ubifs: replace inode uid,gid,mode initialization with helper function
  sysv: replace inode uid,gid,mode initialization with helper function
  reiserfs: replace inode uid,gid,mode initialization with helper function
  ramfs: replace inode uid,gid,mode initialization with helper function
  omfs: replace inode uid,gid,mode initialization with helper function
  bfs: replace inode uid,gid,mode initialization with helper function
  ocfs2: replace inode uid,gid,mode initialization with helper function
  nilfs2: replace inode uid,gid,mode initialization with helper function
  minix: replace inode uid,gid,mode init with helper
  ext4: replace inode uid,gid,mode init with helper
  ...

Trivial conflict in fs/fs-writeback.c (mark bitfields unsigned)
2010-05-21 19:37:45 -07:00
Dmitry Monakhov
454abafe9d ramfs: replace inode uid,gid,mode initialization with helper function
- seems what ramfs_get_inode is only locally, make it static.
[AV: the hell it is; it's used by shmem, so shmem needed conversion too
and no, that function can't be made static]

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-21 18:31:26 -04:00
Christoph Hellwig
8018ab0574 sanitize vfs_fsync calling conventions
Now that the last user passing a NULL file pointer is gone we can remove
the redundant dentry argument and associated hacks inside vfs_fsynmc_range.

The next step will be removig the dentry argument from ->fsync, but given
the luck with the last round of method prototype changes I'd rather
defer this until after the main merge window.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-21 18:31:21 -04:00
Stephen Hemminger
bb4354538e fs: xattr_handler table should be const
The entries in xattr handler table should be immutable (ie const)
like other operation tables.

Later patches convert common filesystems. Uncoverted filesystems
will still work, but will generate a compiler warning.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-21 18:31:18 -04:00
Linus Torvalds
d79df0b1ed Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6: (577 commits)
  Staging: ramzswap: Handler for swap slot free callback
  swap: Add swap slot free callback to block_device_operations
  swap: Add flag to identify block swap devices
  Staging: vt6655: use ETH_FRAME_LEN macro instead of custom one
  Staging: vt6655: use ETH_DATA_LEN macro instead of custom one
  Staging: vt6655: use ETH_FCS_LEN macro instead of custom one
  Staging: vt6656: use ETH_HLEN macro instead of custom one
  Staging: comedi: quatech_daqp_cs.c Replace eos semaphore with a completion.
  Staging: dt3155v4l: remove private memory allocator
  Staging: crystalhd: Remove typedefs from driver
  Staging: winbond: Fix for pointer name format issue in mds.c
  Staging: vt6656: removed custom UCHAR/USHORT/UINT/ULONG/ULONGLONG typedefs
  Staging: vt6656: removed custom CHAR/SHORT/INT/LONG typedefs
  Staging: comedi: Altered the way printk is used in 8255.c
  staging: iio: adis16350 and similar IMU driver
  Staging: iio: max1363 Fix two bugs in single_channel_from_ring
  Staging: iio: adis16220 extract bin_attribute structures from state
  Staging: iio: adis16220 vibration sensor driver
  Staging: comedi: Kconfig dependancy fixes
  Staging: comedi: fix up build error from last Kconfig changes
  ...
2010-05-21 15:26:46 -07:00
Greg Kroah-Hartman
c8d1a12692 Merge staging-next tree into Linus's latest version
Conflicts:
	drivers/staging/arlan/arlan-main.c
	drivers/staging/comedi/drivers/cb_das16_cs.c
	drivers/staging/cx25821/cx25821-alsa.c
	drivers/staging/dt3155/dt3155_drv.c
	drivers/staging/hv/hv.c
	drivers/staging/netwave/netwave_cs.c
	drivers/staging/wavelan/wavelan.c
	drivers/staging/wavelan/wavelan_cs.c
	drivers/staging/wlags49_h2/wl_cs.c

This required a bit of hand merging due to the conflicts
that happened in the later .34-rc releases, as well as
some staging driver changing coming in through other trees
(v4l and pcmcia).

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21 12:48:55 -07:00
Jens Axboe
ee9a3607fb Merge branch 'master' into for-2.6.35
Conflicts:
	fs/ext3/fsync.c

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21 21:27:26 +02:00
Jens Axboe
df96e96f76 writeback: fix mixed up arguments to bdi_start_writeback()
The laptop mode timer had the nr_pages and sb_locked arguments
mixed up.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21 20:01:54 +02:00
Jens Axboe
c2c4986edd writeback: fix problem with !CONFIG_BLOCK compilation
When CONFIG_BLOCK isn't enabled:

mm/page-writeback.c: In function 'laptop_mode_timer_fn':
mm/page-writeback.c:708: error: dereferencing pointer to incomplete type
mm/page-writeback.c:709: error: dereferencing pointer to incomplete type

Fix this by essentially eliminating the laptop sync handlers when
CONFIG_BLOCK isn't set, as most are only used from the block layer code.
The exception is laptop_sync_completion() which is used from sys_sync(),
make that an empty declaration in that case.

Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21 20:01:03 +02:00
Jens Axboe
6423104b6a writeback: fixups for !dirty_writeback_centisecs
Commit 69b62d01 fixed up most of the places where we would enter
busy schedule() spins when disabling the periodic background
writeback. This fixes up the sb timer so that it doesn't get
hammered on with the delay disabled, and ensures that it gets
rearmed if needed when /proc/sys/vm/dirty_writeback_centisecs
gets modified.

bdi_forker_task() also needs to check for !dirty_writeback_centisecs
and use schedule() appropriately, fix that up too.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21 20:00:35 +02:00
Linus Torvalds
f39d01be4c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (44 commits)
  vlynq: make whole Kconfig-menu dependant on architecture
  add descriptive comment for TIF_MEMDIE task flag declaration.
  EEPROM: max6875: Header file cleanup
  EEPROM: 93cx6: Header file cleanup
  EEPROM: Header file cleanup
  agp: use NULL instead of 0 when pointer is needed
  rtc-v3020: make bitfield unsigned
  PCI: make bitfield unsigned
  jbd2: use NULL instead of 0 when pointer is needed
  cciss: fix shadows sparse warning
  doc: inode uses a mutex instead of a semaphore.
  uml: i386: Avoid redefinition of NR_syscalls
  fix "seperate" typos in comments
  cocbalt_lcdfb: correct sections
  doc: Change urls for sparse
  Powerpc: wii: Fix typo in comment
  i2o: cleanup some exit paths
  Documentation/: it's -> its where appropriate
  UML: Fix compiler warning due to missing task_struct declaration
  UML: add kernel.h include to signal.c
  ...
2010-05-20 09:20:59 -07:00
Linus Torvalds
9c688c114c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  ia64: add sparse annotation to __ia64_per_cpu_var()
  percpu: implement kernel memory based chunk allocation
  percpu: move vmalloc based chunk management into percpu-vm.c
  percpu: misc preparations for nommu support
  percpu: reorganize chunk creation and destruction
  percpu: factor out pcpu_addr_in_first/reserved_chunk() and update per_cpu_ptr_to_phys()
2010-05-20 09:02:49 -07:00
David Woodhouse
4581ced379 mm: Move ARCH_SLAB_MINALIGN and ARCH_KMALLOC_MINALIGN to <linux/slub_def.h>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-05-19 22:03:13 +03:00
David Woodhouse
bac49ce42a mm: Move ARCH_SLAB_MINALIGN and ARCH_KMALLOC_MINALIGN to <linux/slob_def.h>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-05-19 22:03:13 +03:00
David Woodhouse
1f0ce8b3dd mm: Move ARCH_SLAB_MINALIGN and ARCH_KMALLOC_MINALIGN to <linux/slab_def.h>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-05-19 22:03:13 +03:00
Nitin Gupta
b3a27d0529 swap: Add swap slot free callback to block_device_operations
This callback is required when RAM based devices are used as swap disks.
One such device is ramzswap which is used as compressed in-memory swap
disk.  For such devices, we need a callback as soon as a swap slot is no
longer used to allow freeing memory allocated for this slot.  Without this
callback, stale data can quickly accumulate in memory defeating the whole
purpose of such devices.

Signed-off-by: Nitin Gupta <ngupta@vflare.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Nigel Cunningham <nigel@tuxonice.net>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-18 15:07:52 -07:00
Nitin Gupta
b272564395 swap: Add flag to identify block swap devices
Added SWP_BLKDEV flag to distinguish block and regular file backed
swap devices. We could also check if a swap is entire block device,
rather than a file, by:
S_ISBLK(swap_info_struct->swap_file->f_mapping->host->i_mode)
but, I think, simply checking this flag is more convenient.

Signed-off-by: Nitin Gupta <ngupta@vflare.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Nigel Cunningham <nigel@tuxonice.net>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-18 15:07:52 -07:00
Linus Torvalds
4d7b4ac22f Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (311 commits)
  perf tools: Add mode to build without newt support
  perf symbols: symbol inconsistency message should be done only at verbose=1
  perf tui: Add explicit -lslang option
  perf options: Type check all the remaining OPT_ variants
  perf options: Type check OPT_BOOLEAN and fix the offenders
  perf options: Check v type in OPT_U?INTEGER
  perf options: Introduce OPT_UINTEGER
  perf tui: Add workaround for slang < 2.1.4
  perf record: Fix bug mismatch with -c option definition
  perf options: Introduce OPT_U64
  perf tui: Add help window to show key associations
  perf tui: Make <- exit menus too
  perf newt: Add single key shortcuts for zoom into DSO and threads
  perf newt: Exit browser unconditionally when CTRL+C, q or Q is pressed
  perf newt: Fix the 'A'/'a' shortcut for annotate
  perf newt: Make <- exit the ui_browser
  x86, perf: P4 PMU - fix counters management logic
  perf newt: Make <- zoom out filters
  perf report: Report number of events, not samples
  perf hist: Clarify events_stats fields usage
  ...

Fix up trivial conflicts in kernel/fork.c and tools/perf/builtin-record.c
2010-05-18 08:19:03 -07:00
Jens Axboe
e913fc825d writeback: fix WB_SYNC_NONE writeback from umount
When umount calls sync_filesystem(), we first do a WB_SYNC_NONE
writeback to kick off writeback of pending dirty inodes, then follow
that up with a WB_SYNC_ALL to wait for it. Since umount already holds
the sb s_umount mutex, WB_SYNC_NONE ends up doing nothing and all
writeback happens as WB_SYNC_ALL. This can greatly slow down umount,
since WB_SYNC_ALL writeback is a data integrity operation and thus
a bigger hammer than simple WB_SYNC_NONE. For barrier aware file systems
it's a lot slower.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-17 12:55:07 +02:00
KAMEZAWA Hiroyuki
747388d78a memcg: fix css_is_ancestor() RCU locking
Some callers (in memcontrol.c) calls css_is_ancestor() without
rcu_read_lock.  Because css_is_ancestor() has to access RCU protected
data, it should be under rcu_read_lock().

This makes css_is_ancestor() itself does safe access to RCU protected
area.  (At least, "root" can have refcnt==0 if it's not an ancestor of
"child".  So, we need rcu_read_lock().)

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-11 17:33:42 -07:00
KAMEZAWA Hiroyuki
7f0f154641 memcg: fix css_id() RCU locking for real
Commit ad4ba37537 ("memcg: css_id() must be
called under rcu_read_lock()") modifies memcontol.c for fixing RCU check
message.  But Andrew Morton pointed out that the fix doesn't seems sane
and it was just for hidining lockdep messages.

This is a patch for do proper things.  Checking again, all places,
accessing without rcu_read_lock, that commit fixies was intentional....
all callers of css_id() has reference count on it.  So, it's not necessary
to be under rcu_read_lock().

Considering again, we can use rcu_dereference_check for css_id().  We know
css->id is valid if css->refcnt > 0.  (css->id never changes and freed
after css->refcnt going to be 0.)

This patch makes use of rcu_dereference_check() in css_id/depth and remove
unnecessary rcu-read-lock added by the commit.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-11 17:33:42 -07:00
Naoya Horiguchi
ab941e0fff rmap: remove anon_vma check in page_address_in_vma()
Currently page_address_in_vma() compares vma->anon_vma and
page_anon_vma(page) for parameter check, but in 2.6.34 a vma can have
multiple anon_vmas with anon_vma_chain, so current check does not work.
(For anonymous page shared by multiple processes, some verified (page,vma)
pairs return -EFAULT wrongly.)

We can go to checking all anon_vmas in the "same_vma" chain, but it needs
to meet lock requirement.  Instead, we can remove anon_vma check safely
because page_address_in_vma() assumes that page and vma are already
checked to belong to the identical process.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Andrea Arcangeli <aarcange@redhat.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>
2010-05-11 17:33:42 -07:00
Mel Gorman
4a6018f7f4 hugetlbfs: kill applications that use MAP_NORESERVE with SIGBUS instead of OOM-killer
Ordinarily, application using hugetlbfs will create mappings with
reserves.  For shared mappings, these pages are reserved before mmap()
returns success and for private mappings, the caller process is guaranteed
and a child process that cannot get the pages gets killed with sigbus.

An application that uses MAP_NORESERVE gets no reservations and mmap()
will always succeed at the risk the page will not be available at fault
time.  This might be used for example on very large sparse mappings where
the developer is confident the necessary huge pages exist to satisfy all
faults even though the whole mapping cannot be backed by huge pages.
Unfortunately, if an allocation does fail, VM_FAULT_OOM is returned to the
fault handler which proceeds to trigger the OOM-killer.  This is
unhelpful.

Even without hugetlbfs mounted, a user using mmap() can trivially trigger
the OOM-killer because VM_FAULT_OOM is returned (will provide example
program if desired - it's a whopping 24 lines long).  It could be
considered a DOS available to an unprivileged user.

This patch alters hugetlbfs to kill a process that uses MAP_NORESERVE
where huge pages were not available with SIGBUS instead of triggering the
OOM killer.

This change affects hugetlb_cow() as well.  I feel there is a failure case
in there, but I didn't create one.  It would need a fairly specific target
in terms of the faulting application and the hugepage pool size.  The
hugetlb_no_page() path is much easier to hit but both might as well be
closed.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-11 17:33:42 -07:00
Linus Torvalds
91bc482ec5 Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  rcu: create rcu_my_thread_group_empty() wrapper
  memcg: css_id() must be called under rcu_read_lock()
  cgroup: Check task_lock in task_subsys_state()
  sched: Fix an RCU warning in print_task()
  cgroup: Fix an RCU warning in alloc_css_id()
  cgroup: Fix an RCU warning in cgroup_path()
  KEYS: Fix an RCU warning in the reading of user keys
  KEYS: Fix an RCU warning
2010-05-07 13:58:21 -07:00
Ingo Molnar
cce9131781 Merge branch 'perf/urgent' into perf/core
Merge reason: Resolve patch dependency

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-07 11:30:30 +02:00
Zhang, Yanmin
111c7d8243 slub: Fix bad boundary check in init_kmem_cache_nodes()
Function init_kmem_cache_nodes is incorrect when checking upper limitation of
kmalloc_caches. The breakage was introduced by commit
91efd773c7 ("dma kmalloc handling fixes").

Acked-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-05-05 21:12:19 +03:00
Paul E. McKenney
ad4ba37537 memcg: css_id() must be called under rcu_read_lock()
This patch fixes task_in_mem_cgroup(), mem_cgroup_uncharge_swapcache(),
mem_cgroup_move_swap_account(), and is_target_pte_for_mc() to protect
calls to css_id().  An additional RCU lockdep splat was reported for
memcg_oom_wake_function(), however, this function is not yet in
mainline as of 2.6.34-rc5.

Reported-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
2010-05-04 09:25:03 -07:00
Tejun Heo
b0c9778b1d percpu: implement kernel memory based chunk allocation
Implement an alternate percpu chunk management based on kernel memeory
for nommu SMP architectures.  Instead of mapping into vmalloc area,
chunks are allocated as a contiguous kernel memory using
alloc_pages().  As such, percpu allocator on nommu will have the
following restrictions.

* It can't fill chunks on-demand page-by-page.  It has to allocate
  each chunk fully upfront.

* It can't support sparse chunk for NUMA configurations.  SMP w/o mmu
  is crazy enough.  Let's hope no one does NUMA w/o mmu.  :-P

* If chunk size isn't power-of-two multiple of PAGE_SIZE, the
  unaligned amount will be wasted on each chunk.  So, archs which use
  this better align chunk size.

For instructions on how to use this, read the comment on top of
mm/percpu-km.c.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: David Howells <dhowells@redhat.com>
Cc: Graff Yang <graff.yang@gmail.com>
Cc: Sonic Zhang <sonic.adi@gmail.com>
2010-05-01 08:30:50 +02:00
Tejun Heo
9f64553256 percpu: move vmalloc based chunk management into percpu-vm.c
Separate out and move chunk management (creation/desctruction and
[de]population) code into percpu-vm.c which is included by percpu.c
and compiled together.  The interface for chunk management is defined
as follows.

 * pcpu_populate_chunk		- populate the specified range of a chunk
 * pcpu_depopulate_chunk	- depopulate the specified range of a chunk
 * pcpu_create_chunk		- create a new chunk
 * pcpu_destroy_chunk		- destroy a chunk, always preceded by full depop
 * pcpu_addr_to_page		- translate address to physical address
 * pcpu_verify_alloc_info	- check alloc_info is acceptable during init

Other than wrapping vmalloc_to_page() inside pcpu_addr_to_page() and
dummy pcpu_verify_alloc_info() implementation, this patch only moves
code around.  This separation is to allow alternate chunk management
implementation.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: David Howells <dhowells@redhat.com>
Cc: Graff Yang <graff.yang@gmail.com>
Cc: Sonic Zhang <sonic.adi@gmail.com>
2010-05-01 08:30:50 +02:00
Tejun Heo
88999a898b percpu: misc preparations for nommu support
Make the following misc preparations for percpu nommu support.

* Remove refernces to vmalloc in common comments as nommu percpu won't
  use it.

* Rename chunk->vms to chunk->data and make it void *.  Its use is
  determined by chunk management implementation.

* Relocate utility functions and add __maybe_unused to functions which
  might not be used by different chunk management implementations.

This patch doesn't cause any functional change.  This is to allow
alternate chunk management implementation for percpu nommu support.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: David Howells <dhowells@redhat.com>
Cc: Graff Yang <graff.yang@gmail.com>
Cc: Sonic Zhang <sonic.adi@gmail.com>
2010-05-01 08:30:50 +02:00
Tejun Heo
6081089fd6 percpu: reorganize chunk creation and destruction
Reorganize alloc/free_pcpu_chunk() such that chunk struct alloc/free
live in pcpu_alloc/free_chunk() and the rest in
pcpu_create/destroy_chunk().  While at it, add missing error handling
for chunk->map allocation failure.

This is to allow alternate chunk management implementation for percpu
nommu support.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: David Howells <dhowells@redhat.com>
Cc: Graff Yang <graff.yang@gmail.com>
Cc: Sonic Zhang <sonic.adi@gmail.com>
2010-05-01 08:30:50 +02:00
Tejun Heo
020ec6537a percpu: factor out pcpu_addr_in_first/reserved_chunk() and update per_cpu_ptr_to_phys()
Factor out pcpu_addr_in_first/reserved_chunk() from
pcpu_chunk_addr_search() and use it to update per_cpu_ptr_to_phys()
such that it handles first chunk differently from the rest.

This patch doesn't cause any functional change and is to prepare for
percpu nommu support.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: David Howells <dhowells@redhat.com>
Cc: Graff Yang <graff.yang@gmail.com>
Cc: Sonic Zhang <sonic.adi@gmail.com>
2010-05-01 08:30:49 +02:00
Ingo Molnar
3ca50496c2 Merge commit 'v2.6.34-rc6' into perf/core
Merge reason: update to the latest -rc.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-30 09:56:44 +02:00
Jens Axboe
7407cf355f Merge branch 'master' into for-2.6.35
Conflicts:
	fs/block_dev.c

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-29 09:36:24 +02:00
Dmitry Monakhov
fbd9b09a17 blkdev: generalize flags for blkdev_issue_fn functions
The patch just convert all blkdev_issue_xxx function to common
set of flags. Wait/allocation semantics preserved.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-28 19:47:36 +02:00
Linus Torvalds
970b06485f Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  coda: move backing-dev.h kernel include inside __KERNEL__
  mtd: ensure that bdi entries are properly initialized and registered
  Move mtd_bdi_*mappable to mtdcore.c
  btrfs: convert to using bdi_setup_and_register()
  Catch filesystems lacking s_bdi
  drbd: Terminate a connection early if sending the protocol fails
  drbd: fix memory leak
  Fix JFFS2 sync silent failure
  smbfs: add bdi backing to mount session
  ncpfs: add bdi backing to mount session
  exofs: add bdi backing to mount session
  ecryptfs: add bdi backing to mount session
  coda: add bdi backing to mount session
  cifs: add bdi backing to mount session
  afs: add bdi backing to mount session.
  9p: add bdi backing to mount session
  bdi: add helper function for doing init and register of a bdi for a file system
  block: ensure jiffies wrap is handled correctly in blk_rq_timed_out_timer
2010-04-28 07:56:05 -07:00
Rik van Riel
5892753383 mmap: check ->vm_ops before dereferencing
Check whether the VMA has a vm_ops before calling close, just
like we check vm_ops before calling open a few dozen lines
higher up in the function.

Signed-off-by: Rik van Riel <riel@redhat.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-27 08:26:51 -07:00
Jörn Engel
5129a469a9 Catch filesystems lacking s_bdi
noop_backing_dev_info is used only as a flag to mark filesystems that
don't have any backing store, like tmpfs, procfs, spufs, etc.

Signed-off-by: Joern Engel <joern@logfs.org>

Changed the BUG_ON() to a WARN_ON(). Note that adding dirty inodes
to the noop_backing_dev_info is not legal and will not result in
them being flushed, but we already catch this condition in
__mark_inode_dirty() when checking for a registered bdi.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-25 08:54:42 +02:00
Dan Carpenter
22eccdd7d2 ksm: check for ERR_PTR from follow_page()
The follow_page() function can potentially return -EFAULT so I added
checks for this.

Also I silenced an uninitialized variable warning on my version of gcc
(version 4.3.2).

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Izik Eidus <ieidus@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-24 11:31:26 -07:00
Oleg Nesterov
31f2b0ebc0 rmap: anon_vma_prepare() can leak anon_vma_chain
If find_mergeable_anon_vma() succeeds but another thread installs
->anon_vma before we take ptl, then allocated == NULL but avc should be
freed.  Change the code to check avc != NULL to detect this case.

Also, a couple of whitespace changes to make the critical section more
visible.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-24 11:31:25 -07:00
Mel Gorman
23be7468e8 hugetlb: fix infinite loop in get_futex_key() when backed by huge pages
If a futex key happens to be located within a huge page mapped
MAP_PRIVATE, get_futex_key() can go into an infinite loop waiting for a
page->mapping that will never exist.

See https://bugzilla.redhat.com/show_bug.cgi?id=552257 for more details
about the problem.

This patch makes page->mapping a poisoned value that includes
PAGE_MAPPING_ANON mapped MAP_PRIVATE.  This is enough for futex to
continue but because of PAGE_MAPPING_ANON, the poisoned value is not
dereferenced or used by futex.  No other part of the VM should be
dereferencing the page->mapping of a hugetlbfs page as its page cache is
not on the LRU.

This patch fixes the problem with the test case described in the bugzilla.

[akpm@linux-foundation.org: mel cant spel]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Darren Hart <darren@dvhart.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-24 11:31:25 -07:00
Andrea Arcangeli
93d5c9be1d memcg: fix prepare migration
If a signal is pending (task being killed by sigkill)
__mem_cgroup_try_charge will write NULL into &mem, and css_put will oops
on null pointer dereference.

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
  IP: [<ffffffff810fc6cc>] mem_cgroup_prepare_migration+0x7c/0xc0
  PGD a5d89067 PUD a5d8a067 PMD 0
  Oops: 0000 [#1] SMP
  last sysfs file: /sys/devices/platform/microcode/firmware/microcode/loading
  CPU 0
  Modules linked in: nfs lockd nfs_acl auth_rpcgss sunrpc acpi_cpufreq pcspkr sg [last unloaded: microcode]

  Pid: 5299, comm: largepages Tainted: G        W  2.6.34-rc3 #3 Penryn1600SLI-110dB/To Be Filled By O.E.M.
  RIP: 0010:[<ffffffff810fc6cc>]  [<ffffffff810fc6cc>] mem_cgroup_prepare_migration+0x7c/0xc0

[nishimura@mxp.nes.nec.co.jp: fix merge issues]
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-24 11:31:24 -07:00
Ingo Molnar
70bce3ba77 Merge branch 'linus' into perf/core
Merge reason: merge the latest fixes, update to latest -rc.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-23 11:10:30 +02:00
Jiri Kosina
6c9468e9eb Merge branch 'master' into for-next 2010-04-23 02:08:44 +02:00
Jens Axboe
c3c532061e bdi: add helper function for doing init and register of a bdi for a file system
Pretty trivial helper, just sets up the bdi and registers it. An atomic
sequence count is used to ensure that the registered sysfs names are
unique.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-22 11:39:36 +02:00
Rik van Riel
e8a03feb54 rmap: add exclusively owned pages to the newest anon_vma
The recent anon_vma fixes cause many anonymous pages to end up
in the parent process anon_vma, even when the page is exclusively
owned by the current process.

Adding exclusively owned anonymous pages to the top anon_vma
reduces rmap scanning overhead, especially in workloads with
forking servers.

This patch adds a parameter to __page_set_anon_rmap that can
be used to indicate whether or not the added page is exclusively
owned by the current process.

Pages added through page_add_new_anon_rmap are exclusively
owned by the current process, and can be added to the top
anon_vma.

Pages added through page_add_anon_rmap can be either shared
or exclusively owned, so we do the conservative thing and
add it to the oldest anon_vma.

A next step would be to add the exclusive parameter to
page_add_anon_rmap, to be used from functions where we do
know for sure whether a page is exclusively owned.

Signed-off-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Lightly-tested-by: Borislav Petkov <bp@alien8.de>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
[ Edited to look nicer  - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-19 16:28:20 -07:00
Shiyong Li
5c5e3b33b7 slab: Fix missing DEBUG_SLAB last user
Even with SLAB_RED_ZONE and SLAB_STORE_USER enabled, kernel would NOT store
redzone and last user data around allocated memory space if "arch cache line >
sizeof(unsigned long long)". As a result, last user information is unexpectedly
MISSED while dumping slab corruption log.

This fix makes sure that redzone and last user tags get stored unless the
required alignment breaks redzone's.

Signed-off-by: Shiyong Li <shi-yong.li@motorola.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-04-14 20:52:45 +03:00
Jens Axboe
4facdaec1c Merge branch 'master' into for-2.6.35
Conflicts:
	block/blk-cgroup.c
	block/cfq-iosched.c

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-13 20:03:21 +02:00
Linus Torvalds
ea90002b0f anonvma: when setting up page->mapping, we need to pick the _oldest_ anonvma
Otherwise we might be mapping in a page in a new mapping, but that page
(through the swapcache) would later be mapped into an old mapping too.
The page->mapping must be the case that works for everybody, not just
the mapping that happened to page it in first.

Here's the scenario:

 - page gets allocated/mapped by process A. Let's call the anon_vma we
   associate the page with 'A' to keep it easy to track.

 - Process A forks, creating process B. The anon_vma in B is 'B', and has
   a chain that looks like 'B' -> 'A'. Everything is fine.

 - Swapping happens. The page (with mapping pointing to 'A') gets swapped
   out (perhaps not to disk - it's enough to assume that it's just not
   mapped any more, and lives entirely in the swap-cache)

 - Process B pages it in, which goes like this:

        do_swap_page ->
          page = lookup_swap_cache(entry);
         ...
          set_pte_at(mm, address, page_table, pte);
          page_add_anon_rmap(page, vma, address);

   And think about what happens here!

   In particular, what happens is that this will now be the "first"
   mapping of that page, so page_add_anon_rmap() used to do

        if (first)
                __page_set_anon_rmap(page, vma, address);

   and notice what anon_vma it will use? It will use the anon_vma for
   process B!

   What happens then? Trivial: process 'A' also pages it in (nothing
   happens, it's not the first mapping), and then process 'B' execve's
   or exits or unmaps, making anon_vma B go away.

   End result: process A has a page that points to anon_vma B, but
   anon_vma B does not exist any more.  This can go on forever.  Forget
   about RCU grace periods, forget about locking, forget anything like
   that.  The bug is simply that page->mapping points to an anon_vma
   that was correct at one point, but was _not_ the one that was shared
   by all users of that possible mapping.

Changing it to always use the deepest anon_vma in the anonvma chain gets
us to the safest model.

This can be improved in certain cases: if we know the page is private to
just this particular mapping (for example, it's a new page, or it is the
only swapcache entry), we could pick the top (most specific) anon_vma.

But that's a future optimization. Make it _work_ reliably first.

Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Tested-by: Borislav Petkov <bp@alien8.de> [ "What do you know, I think you fixed it!" ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-12 17:54:13 -07:00
Linus Torvalds
646d87b481 anon_vma: clone the anon_vma chain in the right order
We want to walk the chain in reverse order when cloning it, so that the
order of the result chain will be the same as the order in the source
chain.  When we add entries to the chain, they go at the head of the
chain, so we want to add the source head last.

Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Tested-by: Borislav Petkov <bp@alien8.de> [ "No, it still oopses" ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-12 17:54:12 -07:00
Linus Torvalds
287d97ac03 vma_adjust: fix the copying of anon_vma chains
When we move the boundaries between two vma's due to things like
mprotect, we need to make sure that the anon_vma of the pages that got
moved from one vma to another gets properly copied around.  And that was
not always the case, in this rather hard-to-follow code sequence.

Clarify the code, and fix it so that it copies the anon_vma from the
right source.

Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Tested-by: Borislav Petkov <bp@alien8.de> [ "Yeah, not so much this one either" ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-12 17:54:11 -07:00
Linus Torvalds
d0e9fe1758 Simplify and comment on anon_vma re-use for anon_vma_prepare()
This changes the anon_vma reuse case to require that we only reuse
simple anon_vma's - ie the case when the vma only has a single anon_vma
associated with it.

This means that a reuse of an anon_vma from an adjacent vma will always
guarantee that both vma's are associated not only with the same
anon_vma, they will also have the same anon_vma chain (of just a single
entry in this case).

And since anon_vma re-use was the only case where the same anon_vma
might be associated with different chains of anon_vma's, we now have the
case that every vma that shares the same anon_vma will always also have
the same chain.  That makes it much easier to think about merging vma's
that share the same anon_vma's: you can always just drop the other
anon_vma chain in anon_vma_merge() since you know that they are always
identical.

This also splits up the function to validate the anon_vma re-use, and
adds a lot of commentary about the possible races.

Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Tested-by: Borislav Petkov <bp@alien8.de> [ "That didn't fix it" ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-12 17:53:59 -07:00
Linus Torvalds
2f4084209a Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: (34 commits)
  cfq-iosched: Fix the incorrect timeslice accounting with forced_dispatch
  loop: Update mtime when writing using aops
  block: expose the statistics in blkio.time and blkio.sectors for the root cgroup
  backing-dev: Handle class_create() failure
  Block: Fix block/elevator.c elevator_get() off-by-one error
  drbd: lc_element_by_index() never returns NULL
  cciss: unlock on error path
  cfq-iosched: Do not merge queues of BE and IDLE classes
  cfq-iosched: Add additional blktrace log messages in CFQ for easier debugging
  i2o: Remove the dangerous kobj_to_i2o_device macro
  block: remove 16 bytes of padding from struct request on 64bits
  cfq-iosched: fix a kbuild regression
  block: make CONFIG_BLK_CGROUP visible
  Remove GENHD_FL_DRIVERFS
  block: Export max number of segments and max segment size in sysfs
  block: Finalize conversion of block limits functions
  block: Fix overrun in lcm() and move it to lib
  vfs: improve writeback_inodes_wb()
  paride: fix off-by-one test
  drbd: fix al-to-on-disk-bitmap for 4k logical_block_size
  ...
2010-04-09 11:50:29 -07:00
Pekka Enberg
d3e06e2b15 slub: Fix kmem_ptr_validate() for non-kernel pointers
As suggested by Linus, fix up kmem_ptr_validate() to handle non-kernel pointers
more graciously. The patch changes kmem_ptr_validate() to use the newly
introduced kern_ptr_validate() helper to check that a pointer is a valid kernel
pointer before we attempt to convert it into a 'struct page'.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-09 10:09:50 -07:00
Pekka Enberg
fc1c183353 slab: Generify kernel pointer validation
As suggested by Linus, introduce a kern_ptr_validate() helper that does some
sanity checks to make sure a pointer is a valid kernel pointer.  This is a
preparational step for fixing SLUB kmem_ptr_validate().

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-09 10:09:50 -07:00
Ingo Molnar
ca7e0c6120 Merge branch 'linus' into perf/core
Semantic conflict: arch/x86/kernel/cpu/perf_event_intel_ds.c

Merge reason: pick up latest fixes, fix the conflict

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-08 13:37:18 +02:00
Linus Torvalds
fb1ae63577 Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-tip:
  x86: Fix double enable_IR_x2apic() call on SMP kernel on !SMP boards
  x86: Increase CONFIG_NODES_SHIFT max to 10
  ibft, x86: Change reserve_ibft_region() to find_ibft_region()
  x86, hpet: Fix bug in RTC emulation
  x86, hpet: Erratum workaround for read after write of HPET comparator
  bootmem, x86: Fix 32bit numa system without RAM on node 0
  nobootmem, x86: Fix 32bit numa system without RAM on node 0
  x86: Handle overlapping mptables
  x86: Make e820_remove_range to handle all covered case
  x86-32, resume: do a global tlb flush in S4 resume
2010-04-07 11:02:23 -07:00
David Rientjes
8f9f8d9e80 slab: add memory hotplug support
Slab lacks any memory hotplug support for nodes that are hotplugged
without cpus being hotplugged.  This is possible at least on x86
CONFIG_MEMORY_HOTPLUG_SPARSE kernels where SRAT entries are marked
ACPI_SRAT_MEM_HOT_PLUGGABLE and the regions of RAM represent a seperate
node.  It can also be done manually by writing the start address to
/sys/devices/system/memory/probe for kernels that have
CONFIG_ARCH_MEMORY_PROBE set, which is how this patch was tested, and
then onlining the new memory region.

When a node is hotadded, a nodelist for that node is allocated and
initialized for each slab cache.  If this isn't completed due to a lack
of memory, the hotadd is aborted: we have a reasonable expectation that
kmalloc_node(nid) will work for all caches if nid is online and memory is
available.

Since nodelists must be allocated and initialized prior to the new node's
memory actually being online, the struct kmem_list3 is allocated off-node
due to kmalloc_node()'s fallback.

When an entire node would be offlined, its nodelists are subsequently
drained.  If slab objects still exist and cannot be freed, the offline is
aborted.  It is possible that objects will be allocated between this
drain and page isolation, so it's still possible that the offline will
still fail, however.

Acked-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-04-07 19:28:31 +03:00
KAMEZAWA Hiroyuki
8725d54162 memcg: fix race in file_mapped accounting
Presently, memcg's FILE_MAPPED accounting has following race with
move_account (happens at rmdir()).

    increment page->mapcount (rmap.c)
    mem_cgroup_update_file_mapped()           move_account()
					      lock_page_cgroup()
					      check page_mapped() if
					      page_mapped(page)>1 {
						FILE_MAPPED -1 from old memcg
						FILE_MAPPED +1 to old memcg
					      }
					      .....
					      overwrite pc->mem_cgroup
					      unlock_page_cgroup()
    lock_page_cgroup()
    FILE_MAPPED + 1 to pc->mem_cgroup
    unlock_page_cgroup()

Then,
	old memcg (-1 file mapped)
	new memcg (+2 file mapped)

This happens because move_account see page_mapped() which is not guarded
by lock_page_cgroup().  This patch adds FILE_MAPPED flag to page_cgroup
and move account information based on it.  Now, all checks are synchronous
with lock_page_cgroup().

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Balbir Singh <balbir@in.ibm.com>
Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Andrea Righi <arighi@develer.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-07 08:38:05 -07:00
Naoya Horiguchi
116354d177 pagemap: fix pfn calculation for hugepage
When we look into pagemap using page-types with option -p, the value of
pfn for hugepages looks wrong (see below.) This is because pte was
evaluated only once for one vma although it should be updated for each
hugepage.  This patch fixes it.

  $ page-types -p 3277 -Nl -b huge
  voffset   offset  len     flags
  7f21e8a00 11e400  1       ___U___________H_G________________
  7f21e8a01 11e401  1ff     ________________TG________________
               ^^^
  7f21e8c00 11e400  1       ___U___________H_G________________
  7f21e8c01 11e401  1ff     ________________TG________________
               ^^^

One hugepage contains 1 head page and 511 tail pages in x86_64 and each
two lines represent each hugepage.  Voffset and offset mean virtual
address and physical address in the page unit, respectively.  The
different hugepages should not have the same offset value.

With this patch applied:

  $ page-types -p 3386 -Nl -b huge
  voffset   offset   len    flags
  7fec7a600 112c00   1      ___UD__________H_G________________
  7fec7a601 112c01   1ff    ________________TG________________
               ^^^
  7fec7a800 113200   1      ___UD__________H_G________________
  7fec7a801 113201   1ff    ________________TG________________
               ^^^
               OK

More info:

- This patch modifies walk_page_range()'s hugepage walker.  But the
  change only affects pagemap_read(), which is the only caller of hugepage
  callback.

- Without this patch, hugetlb_entry() callback is called per vma, that
  doesn't match the natural expectation from its name.

- With this patch, hugetlb_entry() is called per hugepte entry and the
  callback can become much simpler.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-07 08:38:04 -07:00
KOSAKI Motohiro
d6da1a5abc mm: revert "vmscan: get_scan_ratio() cleanup"
Shaohua Li reported his tmpfs streaming I/O test can lead to make oom.
The test uses a 6G tmpfs in a system with 3G memory.  In the tmpfs, there
are 6 copies of kernel source and the test does kbuild for each copy.  His
investigation shows the test has a lot of rotated anon pages and quite few
file pages, so get_scan_ratio calculates percent[0] (i.e.  scanning
percent for anon) to be zero.  Actually the percent[0] shoule be a big
value, but our calculation round it to zero.

Although before commit 84b18490 ("vmscan: get_scan_ratio() cleanup") , we
have the same problem too.  But the old logic can rescue percent[0]==0
case only when priority==0.  It had hided the real issue.  I didn't think
merely streaming io can makes percent[0]==0 && priority==0 situation.  but
I was wrong.

So, definitely we have to fix such tmpfs streaming io issue.  but anyway I
revert the regression commit at first.

This reverts commit 84b18490d1.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reported-by: Shaohua Li <shaohua.li@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-07 08:38:03 -07:00
Wu Fengguang
70655c06bd readahead: fix NULL filp dereference
btrfs relocate_file_extent_cluster() calls us with NULL filp:

  [ 4005.426805] BUG: unable to handle kernel NULL pointer dereference at 00000021
  [ 4005.426818] IP: [<c109a130>] page_cache_sync_readahead+0x18/0x3e

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Yan Zheng <yanzheng@21cn.com>
Reported-by: Kirill A. Shutemov <kirill@shutemov.name>
Tested-by: Kirill A. Shutemov <kirill@shutemov.name>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-07 08:38:03 -07:00
KAMEZAWA Hiroyuki
a3a2e76c77 mm: avoid null-pointer deref in sync_mm_rss()
- We weren't zeroing p->rss_stat[] at fork()

- Consequently sync_mm_rss() was dereferencing tsk->mm for kernel
  threads and was oopsing.

- Make __sync_task_rss_stat() static, too.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=15648

[akpm@linux-foundation.org: remove the BUG_ON(!mm->rss)]
Reported-by: Troels Liebe Bentsen <tlb@rapanden.dk>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
"Michael S. Tsirkin" <mst@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-07 08:38:02 -07:00
Matthew Garrett
31373d09da laptop-mode: Make flushes per-device
One of the features of laptop-mode is that it forces a writeout of dirty
pages if something else triggers a physical read or write from a device.
The current implementation flushes pages on all devices, rather than only
the one that triggered the flush. This patch alters the behaviour so that
only the recently accessed block device is flushed, preventing other
disks being spun up for no terribly good reason.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-06 14:25:14 +02:00
Linus Torvalds
b66696e3c0 Merge branch 'slabh' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc
* 'slabh' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc:
  eeepc-wmi: include slab.h
  staging/otus: include slab.h from usbdrv.h
  percpu: don't implicitly include slab.h from percpu.h
  kmemcheck: Fix build errors due to missing slab.h
  include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
  iwlwifi: don't include iwl-dev.h from iwl-devtrace.h
  x86: don't include slab.h from arch/x86/include/asm/pgtable_32.h

Fix up trivial conflicts in include/linux/percpu.h due to
is_kernel_percpu_address() having been introduced since the slab.h
cleanup with the percpu_up.c splitup.
2010-04-05 09:39:11 -07:00
Linus Torvalds
9e74e7c81a Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  module: add stub for is_module_percpu_address
  percpu, module: implement and use is_kernel/module_percpu_address()
  module: encapsulate percpu handling better and record percpu_size
2010-04-05 09:16:37 -07:00
Rik van Riel
4946d54cb5 rmap: fix anon_vma_fork() memory leak
Fix a memory leak in anon_vma_fork(), where we fail to tear down the
anon_vmas attached to the new VMA in case setting up the new anon_vma
fails.

This bug also has the potential to leave behind anon_vma_chain structs
with pointers to invalid memory.

Reported-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-05 09:15:51 -07:00
Ingo Molnar
ec5e61aabe Merge branch 'perf/urgent' into perf/core
Conflicts:
	arch/x86/kernel/cpu/perf_event.c

Merge reason: Resolve the conflict, pick up fixes

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-02 19:38:10 +02:00
Anton Blanchard
1442145373 backing-dev: Handle class_create() failure
I hit this when we had a bug in IDR for a few days. Basically sysfs would
fail to create new inodes since it uses an IDR and therefore class_create would
fail.

While we are unlikely to see this fail we may as well handle it instead of
oopsing.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-02 09:46:55 +02:00
Yinghai Lu
aa235fc712 bootmem, x86: Fix 32bit numa system without RAM on node 0
When 32bit numa is used, free_all_bootmem() will still only go over with
node id 0.

If node 0 doesn't have RAM installed, the lowest populated node
becomes low RAM.

This one fixes BOOTMEM path by iterating over the bdata_list.

-v3: add more comments, and fix bootmem path too.
-v4: seperate from one big patch

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4BB416D7.6090203@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-04-01 14:41:19 -07:00