Commit Graph

2901 Commits

Author SHA1 Message Date
Tejun Heo
fbf59bc9d7 percpu: implement new dynamic percpu allocator
Impact: new scalable dynamic percpu allocator which allows dynamic
        percpu areas to be accessed the same way as static ones

Implement scalable dynamic percpu allocator which can be used for both
static and dynamic percpu areas.  This will allow static and dynamic
areas to share faster direct access methods.  This feature is optional
and enabled only when CONFIG_HAVE_DYNAMIC_PER_CPU_AREA is defined by
arch.  Please read comment on top of mm/percpu.c for details.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
2009-02-20 16:29:08 +09:00
Tejun Heo
8fc4898500 vmalloc: add un/map_kernel_range_noflush()
Impact: two more public map/unmap functions

Implement map_kernel_range_noflush() and unmap_kernel_range_noflush().
These functions respectively map and unmap address range in kernel VM
area but doesn't do any vcache or tlb flushing.  These will be used by
new percpu allocator.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
2009-02-20 16:29:08 +09:00
Tejun Heo
f0aa661790 vmalloc: implement vm_area_register_early()
Impact: allow multiple early vm areas

There are places where kernel VM area needs to be allocated before
vmalloc is initialized.  This is done by allocating static vm_struct,
initializing several fields and linking it to vmlist and later vmalloc
initialization picking up these from vmlist.  This is currently done
manually and if there's more than one such areas, there's no defined
way to arbitrate who gets which address.

This patch implements vm_area_register_early(), which takes vm_area
struct with flags and size initialized, assigns address to it and puts
it on the vmlist.  This way, multiple early vm areas can determine
which addresses they should use.  The only current user - alpha mm
init - is converted to use it.

Signed-off-by: Tejun Heo <tj@kernel.org>
2009-02-20 16:29:08 +09:00
Tejun Heo
f2a8205c4e percpu: kill percpu_alloc() and friends
Impact: kill unused functions

percpu_alloc() and its friends never saw much action.  It was supposed
to replace the cpu-mask unaware __alloc_percpu() but it never happened
and in fact __percpu_alloc_mask() itself never really grew proper
up/down handling interface either (no exported interface for
populate/depopulate).

percpu allocation is about to go through major reimplementation and
there's no reason to carry this unused interface around.  Replace it
with __alloc_percpu() and free_percpu().

Signed-off-by: Tejun Heo <tj@kernel.org>
2009-02-20 16:29:08 +09:00
Tejun Heo
734269521e vmalloc: call flush_cache_vunmap() from unmap_kernel_range()
Impact: proper vcache flush on unmap_kernel_range()

flush_cache_vunmap() should be called before pages are unmapped.  Add
a call to it in unmap_kernel_range().

Signed-off-by: Tejun Heo <tj@kernel.org>
2009-02-20 16:29:07 +09:00
Ingo Molnar
72c26c9a26 Merge branch 'linus' into tracing/blktrace
Conflicts:
	block/blktrace.c

Semantic merge:
	kernel/trace/blktrace.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-19 09:00:35 +01:00
Linus Torvalds
ba95fd47d1 Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  block: fix deadlock in blk_abort_queue() for drivers that readd to timeout list
  block: fix booting from partitioned md array
  block: revert part of 18ce3751cc
  cciss: PCI power management reset for kexec
  paride/pg.c: xs(): &&/|| confusion
  fs/bio: bio_alloc_bioset: pass right object ptr to mempool_free
  block: fix bad definition of BIO_RW_SYNC
  bsg: Fix sense buffer bug in SG_IO
2009-02-18 18:33:04 -08:00
KAMEZAWA Hiroyuki
cc2559bccc mm: fix memmap init for handling memory hole
Now, early_pfn_in_nid(PFN, NID) may returns false if PFN is a hole.
and memmap initialization was not done. This was a trouble for
sparc boot.

To fix this, the PFN should be initialized and marked as PG_reserved.
This patch changes early_pfn_in_nid() return true if PFN is a hole.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reported-by: David Miller <davem@davemlloft.net>
Tested-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: <stable@kernel.org>		[2.6.25.x, 2.6.26.x, 2.6.27.x, 2.6.28.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-18 15:37:55 -08:00
KAMEZAWA Hiroyuki
f2dbcfa738 mm: clean up for early_pfn_to_nid()
What's happening is that the assertion in mm/page_alloc.c:move_freepages()
is triggering:

	BUG_ON(page_zone(start_page) != page_zone(end_page));

Once I knew this is what was happening, I added some annotations:

	if (unlikely(page_zone(start_page) != page_zone(end_page))) {
		printk(KERN_ERR "move_freepages: Bogus zones: "
		       "start_page[%p] end_page[%p] zone[%p]\n",
		       start_page, end_page, zone);
		printk(KERN_ERR "move_freepages: "
		       "start_zone[%p] end_zone[%p]\n",
		       page_zone(start_page), page_zone(end_page));
		printk(KERN_ERR "move_freepages: "
		       "start_pfn[0x%lx] end_pfn[0x%lx]\n",
		       page_to_pfn(start_page), page_to_pfn(end_page));
		printk(KERN_ERR "move_freepages: "
		       "start_nid[%d] end_nid[%d]\n",
		       page_to_nid(start_page), page_to_nid(end_page));
 ...

And here's what I got:

	move_freepages: Bogus zones: start_page[2207d0000] end_page[2207dffc0] zone[fffff8103effcb00]
	move_freepages: start_zone[fffff8103effcb00] end_zone[fffff8003fffeb00]
	move_freepages: start_pfn[0x81f600] end_pfn[0x81f7ff]
	move_freepages: start_nid[1] end_nid[0]

My memory layout on this box is:

[    0.000000] Zone PFN ranges:
[    0.000000]   Normal   0x00000000 -> 0x0081ff5d
[    0.000000] Movable zone start PFN for each node
[    0.000000] early_node_map[8] active PFN ranges
[    0.000000]     0: 0x00000000 -> 0x00020000
[    0.000000]     1: 0x00800000 -> 0x0081f7ff
[    0.000000]     1: 0x0081f800 -> 0x0081fe50
[    0.000000]     1: 0x0081fed1 -> 0x0081fed8
[    0.000000]     1: 0x0081feda -> 0x0081fedb
[    0.000000]     1: 0x0081fedd -> 0x0081fee5
[    0.000000]     1: 0x0081fee7 -> 0x0081ff51
[    0.000000]     1: 0x0081ff59 -> 0x0081ff5d

So it's a block move in that 0x81f600-->0x81f7ff region which triggers
the problem.

This patch:

Declaration of early_pfn_to_nid() is scattered over per-arch include
files, and it seems it's complicated to know when the declaration is used.
 I think it makes fix-for-memmap-init not easy.

This patch moves all declaration to include/linux/mm.h

After this,
  if !CONFIG_NODES_POPULATES_NODE_MAP && !CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
     -> Use static definition in include/linux/mm.h
  else if !CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
     -> Use generic definition in mm/page_alloc.c
  else
     -> per-arch back end function will be called.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reported-by: David Miller <davem@davemlloft.net>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: <stable@kernel.org>		[2.6.25.x, 2.6.26.x, 2.6.27.x, 2.6.28.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-18 15:37:55 -08:00
Nick Piggin
1cf6e7d83b mm: task dirty accounting fix
YAMAMOTO-san noticed that task_dirty_inc doesn't seem to be called properly for
cases where set_page_dirty is not used to dirty a page (eg. mark_buffer_dirty).

Additionally, there is some inconsistency about when task_dirty_inc is
called.  It is used for dirty balancing, however it even gets called for
__set_page_dirty_no_writeback.

So rather than increment it in a set_page_dirty wrapper, move it down to
exactly where the dirty page accounting stats are incremented.

Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-18 15:37:54 -08:00
Benjamin Herrenschmidt
c296861291 vmalloc: add __get_vm_area_caller()
We have get_vm_area_caller() and __get_vm_area() but not
__get_vm_area_caller()

On powerpc, I use __get_vm_area() to separate the ranges of addresses
given to vmalloc vs.  ioremap (various good reasons for that) so in order
to be able to implement the new caller tracking in /proc/vmallocinfo, I
need a "_caller" variant of it.

(akpm: needed for ongoing powerpc development, so merge it early)

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-18 15:37:53 -08:00
Jens Axboe
93dbb39350 block: fix bad definition of BIO_RW_SYNC
We can't OR shift values, so get rid of BIO_RW_SYNC and use BIO_RW_SYNCIO
and BIO_RW_UNPLUG explicitly. This brings back the behaviour from before
213d9417fe.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-02-18 10:32:00 +01:00
Linus Torvalds
35010334aa Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, vm86: fix preemption bug
  x86, olpc: fix model detection without OFW
  x86, hpet: fix for LS21 + HPET = boot hang
  x86: CPA avoid repeated lazy mmu flush
  x86: warn if arch_flush_lazy_mmu_cpu is called in preemptible context
  x86/paravirt: make arch_flush_lazy_mmu/cpu disable preemption
  x86, pat: fix warn_on_once() while mapping 0-1MB range with /dev/mem
  x86/cpa: make sure cpa is safe to call in lazy mmu mode
  x86, ptrace, mm: fix double-free on race
2009-02-17 14:27:39 -08:00
Ingo Molnar
6700ec65c2 lockdep: annotate reclaim context (__GFP_NOFS), fix
Impact: fix build warning

Fix:

  mm/vmscan.c: In function ‘kswapd’:
  mm/vmscan.c:1969: warning: ISO C90 forbids mixed declarations and code

node_to_cpumask_ptr(cpumask, pgdat->node_id), has a side-effect: it
defines the 'cpumask' local variable as well, so it has to go into
the variable definition section.

Sidenote: it might make sense to make this purpose of these macros
more apparent, by naming them the standard way, such as:

  DEFINE_node_to_cpumask_ptr(cpumask, pgdat->node_id);

(But that is outside the scope of this patch.)

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Mike Travis <travis@sgi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-15 21:22:48 +01:00
Nick Piggin
cf40bd16fd lockdep: annotate reclaim context (__GFP_NOFS)
Here is another version, with the incremental patch rolled up, and
added reclaim context annotation to kswapd, and allocation tracing
to slab allocators (which may only ever reach the page allocator
in rare cases, so it is good to put annotations here too).

Haven't tested this version as such, but it should be getting closer
to merge worthy ;)

--
After noticing some code in mm/filemap.c accidentally perform a __GFP_FS
allocation when it should not have been, I thought it might be a good idea to
try to catch this kind of thing with lockdep.

I coded up a little idea that seems to work. Unfortunately the system has to
actually be in __GFP_FS page reclaim, then take the lock, before it will mark
it. But at least that might still be some orders of magnitude more common
(and more debuggable) than an actual deadlock condition, so we have some
improvement I hope (the concept is no less complete than discovery of a lock's
interrupt contexts).

I guess we could even do the same thing with __GFP_IO (normal reclaim), and
even GFP_NOIO locks too... but filesystems will have the most locks and fiddly
code paths, so let's start there and see how it goes.

It *seems* to work. I did a quick test.

=================================
[ INFO: inconsistent lock state ]
2.6.28-rc6-00007-ged31348-dirty #26
---------------------------------
inconsistent {in-reclaim-W} -> {ov-reclaim-W} usage.
modprobe/8526 [HC0[0]:SC0[0]:HE1:SE1] takes:
 (testlock){--..}, at: [<ffffffffa0020055>] brd_init+0x55/0x216 [brd]
{in-reclaim-W} state was registered at:
  [<ffffffff80267bdb>] __lock_acquire+0x75b/0x1a60
  [<ffffffff80268f71>] lock_acquire+0x91/0xc0
  [<ffffffff8070f0e1>] mutex_lock_nested+0xb1/0x310
  [<ffffffffa002002b>] brd_init+0x2b/0x216 [brd]
  [<ffffffff8020903b>] _stext+0x3b/0x170
  [<ffffffff80272ebf>] sys_init_module+0xaf/0x1e0
  [<ffffffff8020c3fb>] system_call_fastpath+0x16/0x1b
  [<ffffffffffffffff>] 0xffffffffffffffff
irq event stamp: 3929
hardirqs last  enabled at (3929): [<ffffffff8070f2b5>] mutex_lock_nested+0x285/0x310
hardirqs last disabled at (3928): [<ffffffff8070f089>] mutex_lock_nested+0x59/0x310
softirqs last  enabled at (3732): [<ffffffff8061f623>] sk_filter+0x83/0xe0
softirqs last disabled at (3730): [<ffffffff8061f5b6>] sk_filter+0x16/0xe0

other info that might help us debug this:
1 lock held by modprobe/8526:
 #0:  (testlock){--..}, at: [<ffffffffa0020055>] brd_init+0x55/0x216 [brd]

stack backtrace:
Pid: 8526, comm: modprobe Not tainted 2.6.28-rc6-00007-ged31348-dirty #26
Call Trace:
 [<ffffffff80265483>] print_usage_bug+0x193/0x1d0
 [<ffffffff80266530>] mark_lock+0xaf0/0xca0
 [<ffffffff80266735>] mark_held_locks+0x55/0xc0
 [<ffffffffa0020000>] ? brd_init+0x0/0x216 [brd]
 [<ffffffff802667ca>] trace_reclaim_fs+0x2a/0x60
 [<ffffffff80285005>] __alloc_pages_internal+0x475/0x580
 [<ffffffff8070f29e>] ? mutex_lock_nested+0x26e/0x310
 [<ffffffffa0020000>] ? brd_init+0x0/0x216 [brd]
 [<ffffffffa002006a>] brd_init+0x6a/0x216 [brd]
 [<ffffffffa0020000>] ? brd_init+0x0/0x216 [brd]
 [<ffffffff8020903b>] _stext+0x3b/0x170
 [<ffffffff8070f8b9>] ? mutex_unlock+0x9/0x10
 [<ffffffff8070f83d>] ? __mutex_unlock_slowpath+0x10d/0x180
 [<ffffffff802669ec>] ? trace_hardirqs_on_caller+0x12c/0x190
 [<ffffffff80272ebf>] sys_init_module+0xaf/0x1e0
 [<ffffffff8020c3fb>] system_call_fastpath+0x16/0x1b

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-14 23:27:49 +01:00
Ingo Molnar
1c511f740f Merge branches 'tracing/ftrace', 'tracing/ring-buffer', 'tracing/sysprof', 'tracing/urgent' and 'linus' into tracing/core 2009-02-13 10:25:18 +01:00
Ingo Molnar
7032e86967 Merge branches 'x86/paravirt', 'x86/pat', 'x86/setup-v2', 'x86/subarch', 'x86/uaccess' and 'x86/urgent' into x86/core 2009-02-13 09:47:32 +01:00
Linus Torvalds
071a0bc2ce Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  mm: Export symbol ksize()
2009-02-12 09:56:14 -08:00
Nick Piggin
3a4c6800f3 Fix page writeback thinko, causing Berkeley DB slowdown
A bug was introduced into write_cache_pages cyclic writeout by commit
31a12666d8 ("mm: write_cache_pages cyclic
fix").  The intention (and comments) is that we should cycle back and
look for more dirty pages at the beginning of the file if there is no
more work to be done.

But the !done condition was dropped from the test.  This means that any
time the page writeout loop breaks (eg.  due to nr_to_write == 0), we
will set index to 0, then goto again.  This will set done_index to
index, then find done is set, so will proceed to the end of the
function.  When updating mapping->writeback_index for cyclic writeout,
we now use done_index == 0, so we're always cycling back to 0.

This seemed to be causing random mmap writes (slapadd and iozone) to
start writing more pages from the LRU and writeout would slowdown, and
caused bugzilla entry

	http://bugzilla.kernel.org/show_bug.cgi?id=12604

about Berkeley DB slowing down dramatically.

With this patch, iozone random write performance is increased nearly
5x on my system (iozone -B -r 4k -s 64k -s 512m -s 1200m on ext2).

Signed-off-by: Nick Piggin <npiggin@suse.de>
Reported-and-tested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-12 08:10:53 -08:00
Kirill A. Shutemov
b1aabecd55 mm: Export symbol ksize()
Commit 7b2cd92adc ("crypto: api - Fix
zeroing on free") added modular user of ksize(). Export that to fix
crypto.ko compilation.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2009-02-12 17:50:46 +02:00
Jeremy Fitzhardinge
9480c53e9b mm: rearrange exit_mmap() to unlock before arch_exit_mmap
Christophe Saout reported [in precursor to:
http://marc.info/?l=linux-kernel&m=123209902707347&w=4]:

> Note that I also some a different issue with CONFIG_UNEVICTABLE_LRU.
> Seems like Xen tears down current->mm early on process termination, so
> that __get_user_pages in exit_mmap causes nasty messages when the
> process had any mlocked pages.  (in fact, it somehow manages to get into
> the swapping code and produces a null pointer dereference trying to get
> a swap token)

Jeremy explained:

Yes.  In the normal case under Xen, an in-use pagetable is "pinned",
meaning that it is RO to the kernel, and all updates must go via hypercall
(or writes are trapped and emulated, which is much the same thing).  An
unpinned pagetable is not currently in use by any process, and can be
directly accessed as normal RW pages.

As an optimisation at process exit time, we unpin the pagetable as early
as possible (switching the process to init_mm), so that all the normal
pagetable teardown can happen with direct memory accesses.

This happens in exit_mmap() -> arch_exit_mmap().  The munlocking happens
a few lines below.  The obvious thing to do would be to move
arch_exit_mmap() to below the munlock code, but I think we'd want to
call it even if mm->mmap is NULL, just to be on the safe side.

Thus, this patch:

exit_mmap() needs to unlock any locked vmas before calling arch_exit_mmap,
as the latter may switch the current mm to init_mm, which would cause the
former to fail.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christophe Saout <christophe@saout.de>
Cc: Keir Fraser <keir.fraser@eu.citrix.com>
Cc: Christophe Saout <christophe@saout.de>
Cc: Alex Williamson <alex.williamson@hp.com>
Cc: <stable@kernel.org>		[2.6.28.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-11 14:25:37 -08:00
Federico Cuello
89e1219004 writeback: fix break condition
Commit dcf6a79dda ("write-back: fix
nr_to_write counter") fixed nr_to_write counter, but didn't set the break
condition properly.

If nr_to_write == 0 after being decremented it will loop one more time
before setting done = 1 and breaking the loop.

[akpm@linux-foundation.org: coding-style fixes]
Cc: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-11 14:25:37 -08:00
KAMEZAWA Hiroyuki
2e9c237243 memcg: use __GFP_NOWARN in page cgroup allocation
page_cgroup's page allocation at init/memory hotplug uses kmalloc() and
vmalloc(). If kmalloc() failes, vmalloc() is used.

This is because vmalloc() is very limited resource on 32bit systems.
We want to use kmalloc() first.

But in this kind of call, __GFP_NOWARN should be specified.

Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-11 14:25:35 -08:00
MinChan Kim
508b9f8efd mm: fix mlocked page counter mismatch
When I tested following program, I found that the mlocked counter
is strange.  It cannot free some mlocked pages.

It is because try_to_unmap_file() doesn't check real
page mappings in vmas.

That is because the goal of an address_space for a file is to find all
processes into which the file's specific interval is mapped.  It is
related to the file's interval, not to pages.

Even if the page isn't really mapped by the vma, it returns SWAP_MLOCK
since the vma has VM_LOCKED, then calls try_to_mlock_page.  After this the
mlocked counter is increased again.

COWed anon page in a file-backed vma could be a such case.  This patch
resolves it.

-- my test program --

int main()
{
       mlockall(MCL_CURRENT);
       return 0;
}

-- before --

root@barrios-target-linux:~# cat /proc/meminfo | egrep 'Mlo|Unev'
Unevictable:           0 kB
Mlocked:               0 kB

-- after --

root@barrios-target-linux:~# cat /proc/meminfo | egrep 'Mlo|Unev'
Unevictable:           8 kB
Mlocked:               8 kB

Signed-off-by: MinChan Kim <minchan.kim@gmail.com>
Acked-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Tested-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-11 14:25:35 -08:00
Sven Wegener
fc3501d411 mm: fix dirty_bytes/dirty_background_bytes sysctls on 64bit arches
We need to pass an unsigned long as the minimum, because it gets casted
to an unsigned long in the sysctl handler. If we pass an int, we'll
access four more bytes on 64bit arches, resulting in a random minimum
value.

[rientjes@google.com: fix type of `old_bytes']
Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-11 14:25:35 -08:00
Daisuke Nishimura
1001c9fb87 migration: migrate_vmas should check "vma"
migrate_vmas() should check "vma" not "vma->vm_next" for for-loop condition.

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-11 14:25:34 -08:00
Mel Gorman
17c9d12e12 Do not account for hugetlbfs quota at mmap() time if mapping [SHM|MAP]_NORESERVE
Commit 5a6fe12595 brought hugetlbfs more
in line with the core VM by obeying VM_NORESERVE and not reserving
hugepages for both shared and private mappings when [SHM|MAP]_NORESERVE
are specified.  However, it is still taking filesystem quota
unconditionally.

At fault time, if there are no reserves and attempt is made to allocate
the page and account for filesystem quota.  If either fail, the fault
fails.  The impact is that quota is getting accounted for twice.  This
patch partially reverts 5a6fe12595.  To
help prevent this mistake happening again, it improves the documentation
of hugetlb_reserve_pages()

Reported-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-11 12:38:09 -08:00
Markus Metzger
9f339e7028 x86, ptrace, mm: fix double-free on race
Ptrace_detach() races with __ptrace_unlink() if the traced task is
reaped while detaching. This might cause a double-free of the BTS
buffer.

Change the ptrace_detach() path to only do the memory accounting in
ptrace_bts_detach() and leave the buffer free to ptrace_bts_untrace()
which will be called from __ptrace_unlink().

The fix follows a proposal from Oleg Nesterov.

Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-11 15:44:20 +01:00
Mel Gorman
5a6fe12595 Do not account for the address space used by hugetlbfs using VM_ACCOUNT
When overcommit is disabled, the core VM accounts for pages used by anonymous
shared, private mappings and special mappings. It keeps track of VMAs that
should be accounted for with VM_ACCOUNT and VMAs that never had a reserve
with VM_NORESERVE.

Overcommit for hugetlbfs is much riskier than overcommit for base pages
due to contiguity requirements. It avoids overcommiting on both shared and
private mappings using reservation counters that are checked and updated
during mmap(). This ensures (within limits) that hugepages exist in the
future when faults occurs or it is too easy to applications to be SIGKILLed.

As hugetlbfs makes its own reservations of a different unit to the base page
size, VM_ACCOUNT should never be set. Even if the units were correct, we would
double account for the usage in the core VM and hugetlbfs. VM_NORESERVE may
be set because an application can request no reserves be made for hugetlbfs
at the risk of getting killed later.

With commit fc8744adc8, VM_NORESERVE and
VM_ACCOUNT are getting unconditionally set for hugetlbfs-backed mappings. This
breaks the accounting for both the core VM and hugetlbfs, can trigger an
OOM storm when hugepage pools are too small lockups and corrupted counters
otherwise are used. This patch brings hugetlbfs more in line with how the
core VM treats VM_NORESERVE but prevents VM_ACCOUNT being set.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-10 10:48:42 -08:00
Ingo Molnar
f9915bfef3 Merge branches 'tracing/ftrace' and 'tracing/urgent' into tracing/core 2009-02-10 13:25:42 +01:00
Ingo Molnar
4ad476e11f Merge commit 'v2.6.29-rc4' into tracing/core 2009-02-09 10:32:48 +01:00
Hugh Dickins
d5b562330e mm: fix error case in mlock downgrade reversion
Commit 27421e211a, Manually revert
"mlock: downgrade mmap sem while populating mlocked regions", has
introduced its own regression: __mlock_vma_pages_range() may report
an error (for example, -EFAULT from trying to lock down pages from
beyond EOF), but mlock_vma_pages_range() must hide that from its
callers as before.

Reported-by: Sami Farin <safari-kernel@safari.iki.fi>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-08 13:53:28 -08:00
Carsten Otte
ab92661d5d do_wp_page: fix regression with execute in place
Fix do_wp_page for VM_MIXEDMAP mappings.

In the case where pfn_valid returns 0 for a pfn at the beginning of
do_wp_page and the mapping is not shared writable, the code branches to
label `gotten:' with old_page == NULL.

In case the vma is locked (vma->vm_flags & VM_LOCKED), lock_page,
clear_page_mlock, and unlock_page try to access the old_page.

This patch checks whether old_page is valid before it is dereferenced.

The regression was introduced by "mlock: mlocked pages are unevictable"
(commit b291f00039).

Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: <stable@kernel.org>		[2.6.28.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-05 12:56:48 -08:00
Ingo Molnar
43769f10b4 Merge branches 'tracing/ftrace' and 'linus' into tracing/core 2009-02-05 14:33:31 +01:00
Artem Bityutskiy
dcf6a79dda write-back: fix nr_to_write counter
Commit 05fe478dd0 introduced some
@wbc->nr_to_write breakage.

It made the following changes:
 1. Decrement wbc->nr_to_write instead of nr_to_write
 2. Decrement wbc->nr_to_write _only_ if wbc->sync_mode == WB_SYNC_NONE
 3. If synced nr_to_write pages, stop only if if wbc->sync_mode ==
    WB_SYNC_NONE, otherwise keep going.

However, according to the commit message, the intention was to only make
change 3.  Change 1 is a bug.  Change 2 does not seem to be necessary,
and it breaks UBIFS expectations, so if needed, it should be done
separately later.  And change 2 does not seem to be documented in the
commit message.

This patch does the following:
 1. Undo changes 1 and 2
 2. Add a comment explaining change 3 (it very useful to have comments
    in _code_, not only in the commit).

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-03 16:59:08 -08:00
Ingo Molnar
dc573f9b20 Merge branches 'tracing/ftrace', 'tracing/kmemtrace' and 'linus' into tracing/core 2009-02-03 06:25:38 +01:00
Linus Torvalds
859281ff37 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  slub: fix per cpu kmem_cache_cpu array memory leak
  kmalloc: return NULL instead of link failure
2009-02-02 19:27:00 -08:00
Linus Torvalds
27421e211a Manually revert "mlock: downgrade mmap sem while populating mlocked regions"
This essentially reverts commit 8edb08caf6.

It downgraded our mmap semaphore to a read-lock while mlocking pages, in
order to allow other threads (and external accesses like "ps" et al) to
walk the vma lists and take page faults etc.  Which is a nice idea, but
the implementation does not work.

Because we cannot upgrade the lock back to a write lock without
releasing the mmap semaphore, the code had to release the lock entirely
and then re-take it as a writelock.  However, that meant that the caller
possibly lost the vma chain that it was following, since now another
thread could come in and mmap/munmap the range.

The code tried to work around that by just looking up the vma again and
erroring out if that happened, but quite frankly, that was just a buggy
hack that doesn't actually protect against anything (the other thread
could just have replaced the vma with another one instead of totally
unmapping it).

The only way to downgrade to a read map _reliably_ is to do it at the
end, which is likely the right thing to do: do all the 'vma' operations
with the write-lock held, then downgrade to a read after completing them
all, and then do the "populate the newly mlocked regions" while holding
just the read lock.  And then just drop the read-lock and return to user
space.

The (perhaps somewhat simpler) alternative is to just make all the
callers of mlock_vma_pages_range() know that the mmap lock got dropped,
and just re-grab the mmap semaphore if it needs to mlock more than one
vma region.

So we can do this "downgrade mmap sem while populating mlocked regions"
thing right, but the way it was done here was absolutely not correct.
Thus the revert, in the expectation that we will do it all correctly
some day.

Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-01 11:00:16 -08:00
Linus Torvalds
fc8744adc8 Stop playing silly games with the VM_ACCOUNT flag
The mmap_region() code would temporarily set the VM_ACCOUNT flag for
anonymous shared mappings just to inform shmem_zero_setup() that it
should enable accounting for the resulting shm object.  It would then
clear the flag after calling ->mmap (for the /dev/zero case) or doing
shmem_zero_setup() (for the MAP_ANON case).

This just resulted in vma merge issues, but also made for just
unnecessary confusion.  Use the already-existing VM_NORESERVE flag for
this instead, and let shmem_{zero|file}_setup() just figure it out from
that.

This also happens to make it obvious that the new DRI2 GEM layer uses a
non-reserving backing store for its object allocation - which is quite
possibly not intentional.  But since I didn't want to change semantics
in this patch, I left it alone, and just updated the caller to use the
new flag semantics.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-31 15:08:56 -08:00
Linus Torvalds
33bfad54b5 Allow opportunistic merging of VM_CAN_NONLINEAR areas
Commit de33c8db59 ("Fix OOPS in
mmap_region() when merging adjacent VM_LOCKED file segments") unified
the vma merging of anonymous and file maps to just one place, which
simplified the code and fixed a use-after-free bug that could cause an
oops.

But by doing the merge opportunistically before even having called
->mmap() on the file method, it now compares two different 'vm_flags'
values: the pre-mmap() value of the new not-yet-formed vma, and previous
mappings of the same file around it.

And in doing so, it refused to merge the common file case, which adds a
marker to say "I can be made non-linear".

This fixes it by just adding a set of flags that don't have to match,
because we know they are ok to merge.  Currently it's only that single
VM_CAN_NONLINEAR flag, but at least conceptually there could be others
in the future.

Reported-and-acked-by: Hugh Dickins <hugh@veritas.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg KH <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-30 11:37:22 -08:00
KAMEZAWA Hiroyuki
299b4eaa30 memcg: NULL pointer dereference at rmdir on some NUMA systems
N_POSSIBLE doesn't means there is memory...and force_empty can
visit invalid node which have no pgdat.

To visit all valid nodes, N_HIGH_MEMORY should be used.

Reported-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-29 18:04:44 -08:00
KAMEZAWA Hiroyuki
85d9fc89fb memcg: fix refcnt handling at swapoff
Now, at swapoff, even while try_charge() fails, commit is executed.  This
is a bug which turns the refcnt of cgroup_subsys_state negative.

Reported-by: Li Zefan <lizf@cn.fujitsu.com>
Tested-by: Li Zefan <lizf@cn.fujitsu.com>
Tested-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-29 18:04:43 -08:00
Daisuke Nishimura
7bcc1bb123 memcg: get/put parents at create/free
The lifetime of struct cgroup and struct mem_cgroup is different and
mem_cgroup has its own reference count for handling references from
swap_cgroup.

This causes strange problem that the parent mem_cgroup dies while child
mem_cgroup alive, and this problem causes a bug in case of
use_hierarchy==1 because res_counter_uncharge climbs up the tree.

This patch is for avoiding it by getting the parent at create, and putting
it at freeing.

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Reviewed-by; KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-29 18:04:43 -08:00
Linus Torvalds
de33c8db59 Fix OOPS in mmap_region() when merging adjacent VM_LOCKED file segments
As of commit ba470de431 ("map: handle
mlocked pages during map, remap, unmap") we now use the 'vma' variable
at the end of mmap_region() to handle the page-in of newly mapped
mlocked pages.

However, if we merged adjacent vma's together, the vma we're using may
be stale.  We historically consciously avoided using it after the merge
operation, but that got overlooked when redoing the locked page
handling.

This commit simplifies mmap_region() by doing any vma merges early,
avoiding the issue entirely, and 'vma' will always be valid.  As pointed
out by Hugh Dickins, this depends on any drivers that change the page
offset of flags to have set one of the VM_SPECIAL bits (so that they
cannot trigger the early merge logic), but that's true in general.

Reported-and-tested-by: Maksim Yevmenkin <maksim.yevmenkin@gmail.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-29 17:46:42 -08:00
David Rientjes
3718909448 slub: fix per cpu kmem_cache_cpu array memory leak
The per cpu array of kmem_cache_cpu structures accomodates
NR_KMEM_CACHE_CPU such structs.

When this array overflows and a struct is allocated by kmalloc(), it may
have an address at the upper bound of this array.  If this happens, it
does not get freed and the per cpu kmem_cache_cpu_free pointer will be out
of bounds after kmem_cache_destroy() or cpu offlining.

Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2009-01-28 10:43:42 +02:00
Greg Ungerer
05ae6fa318 uclinux: add process name to allocation error message
This patch adds the name of the process to the bad allocation error
message on non-MMU systems.

Changed suggested by jsujjavanich@syntech-fuelmaster.com

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
2009-01-27 16:42:03 +10:00
Paul Mundt
eb6434d9e7 nommu: Stub in vm_map_ram()/vm_unmap_ram()/vm_unmap_aliases().
Presently we do not support these interfaces, so make them BUG() wrappers
as per the rest of the vmap interface on nommu. Fixes up the modular xfs
build.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-01-21 17:45:47 +09:00
Ingo Molnar
4092762aeb Merge branch 'tracing/ftrace'; commit 'v2.6.29-rc2' into tracing/core 2009-01-18 20:15:05 +01:00
Li Zefan
068b38c1fa memcg: fix a race when setting memory.swappiness
(suppose: memcg->use_hierarchy == 0 and memcg->swappiness == 60)

echo 10 > /memcg/0/swappiness   |
  mem_cgroup_swappiness_write() |
    ...                         | echo 1 > /memcg/0/use_hierarchy
                                | mkdir /mnt/0/1
                                |   sub_memcg->swappiness = 60;
    memcg->swappiness = 10;     |

In the above scenario, we end up having 2 different swappiness
values in a single hierarchy.

We should hold cgroup_lock() when cheking cgrp->children list.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-15 16:39:41 -08:00
Li Zefan
0eb253e223 memcg: fix section mismatch
At system boot when creating the top cgroup, mem_cgroup_create() calls
enable_swap_cgroup() which is marked as __init, so mark
mem_cgroup_create() as __ref to avoid false section mismatch warning.

Reported-by: Rakib Mullick <rakib.mullick@gmail.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by; KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
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>
2009-01-15 16:39:41 -08:00
Andrew Morton
46666d8ac4 revert "mm: vmalloc use mutex for purge"
Revert commit e97a630eb0 ("mm: vmalloc use
mutex for purge")

Bryan Donlan reports:

: After testing 2.6.29-rc1 on xen-x86 with a btrfs root filesystem, I
: got the OOPS quoted below and a hard freeze shortly after boot.
: Boot messages and config are attached.
:
: ------------[ cut here ]------------
: Kernel BUG at c05ef80d [verbose debug info unavailable]
: invalid opcode: 0000 [#1] SMP
: last sysfs file: /sys/block/xvdc/size
: Modules linked in:
:
: Pid: 0, comm: swapper Not tainted (2.6.29-rc1 #6)
: EIP: 0061:[<c05ef80d>] EFLAGS: 00010087 CPU: 2
: EIP is at schedule+0x7cd/0x950
: EAX: d5aeca80 EBX: 00000002 ECX: 00000000 EDX: d4cb9a40
: ESI: c12f5600 EDI: d4cb9a40 EBP: d6033fa4 ESP: d6033ef4
:  DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0069
: Process swapper (pid: 0, ti=d6032000 task=d6020b70 task.ti=d6032000)
: Stack:
:  000d85bc 00000000 000186a0 00000000 0dd11410 c0105417 c12efe00 0dc367c3
:  00000011 c0105d46 d5a5d310 deadbeef d4cb9a40 c07cc600 c05f1340 c12e0060
:  deadbeef d6020b70 d6020d08 00000002 c014377d 00000000 c12f5600 00002c22
: Call Trace:
:  [<c0105417>] xen_force_evtchn_callback+0x17/0x30
:  [<c0105d46>] check_events+0x8/0x12
:  [<c05f1340>] _spin_unlock_irqrestore+0x20/0x40
:  [<c014377d>] hrtimer_start_range_ns+0x12d/0x2e0
:  [<c014c4f6>] tick_nohz_restart_sched_tick+0x146/0x160
:  [<c0107485>] cpu_idle+0xa5/0xc0

and bisected it to this commit.

Let's remove it now while we have a think about the problem.

Reported-by: Bryan Donlan <bdonlan@gmail.com>
Tested-by: Christophe Saout <christophe@saout.de>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-15 16:39:40 -08:00
Daisuke Nishimura
4d1c627389 memcg: make oom less frequently
In previous implementation, mem_cgroup_try_charge checked the return
value of mem_cgroup_try_to_free_pages, and just retried if some pages
had been reclaimed.
But now, try_charge(and mem_cgroup_hierarchical_reclaim called from it)
only checks whether the usage is less than the limit.

This patch tries to change the behavior as before to cause oom less
frequently.

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-15 16:39:39 -08:00
Daisuke Nishimura
c268e9946d memcg: fix hierarchical reclaim
If root_mem has no children, last_scaned_child is set to root_mem itself.
But after some children added to root_mem, mem_cgroup_get_next_node can
mem_cgroup_put the root_mem although root_mem has not been mem_cgroup_get.

This patch fixes this behavior by:

- Set last_scanned_child to NULL if root_mem has no children or DFS
  search has returned to root_mem itself(root_mem is not a "child" of
  root_mem).  Make mem_cgroup_get_first_node return root_mem in this case.
   There are no mem_cgroup_get/put for root_mem.

- Rename mem_cgroup_get_next_node to __mem_cgroup_get_next_node, and
  mem_cgroup_get_first_node to mem_cgroup_get_next_node.  Make
  mem_cgroup_hierarchical_reclaim call only new mem_cgroup_get_next_node.

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-15 16:39:39 -08:00
Daisuke Nishimura
40d58138f8 memcg: fix error path of mem_cgroup_move_parent
There is a bug in error path of mem_cgroup_move_parent.

Extra refcnt got from try_charge should be dropped, and usages incremented
by try_charge should be decremented in both error paths:

    A: failure at get_page_unless_zero
    B: failure at isolate_lru_page

This bug makes this parent directory unremovable.

In case of A, rmdir doesn't return, because res.usage doesn't go down to 0
at mem_cgroup_force_empty even after all the pc in lru are removed.

In case of B, rmdir fails and returns -EBUSY, because it has extra ref
counts even after res.usage goes down to 0.

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-15 16:39:39 -08:00
Daisuke Nishimura
bd112db872 memcg: fix mem_cgroup_get_reclaim_stat_from_page
In case of swapin, a new page is added to lru before it is charged,
so page->pc->mem_cgroup points to NULL or last mem_cgroup the page
was charged before.

In the latter case, if the mem_cgroup has already freed by rmdir,
the area pointed to by page->pc->mem_cgroup may have invalid data.

Actually, I saw general protection fault.

    general protection fault: 0000 [#1] SMP
    last sysfs file: /sys/devices/system/cpu/cpu15/cache/index1/shared_cpu_map
    CPU 4
    Modules linked in: ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables bridge stp ipv6 autofs4 hidp rfcomm l2cap bluetooth sunrpc dm_mirror dm_region_hash dm_log dm_multipath dm_mod rfkill input_polldev sbs sbshc battery ac lp sg ide_cd_mod cdrom button serio_raw acpi_memhotplug parport_pc e1000 rtc_cmos parport rtc_core rtc_lib i2c_i801 i2c_core shpchp pcspkr ata_piix libata megaraid_mbox megaraid_mm sd_mod scsi_mod ext3 jbd ehci_hcd ohci_hcd uhci_hcd [last unloaded: microcode]
    Pid: 26038, comm: page01 Tainted: G        W  2.6.28-rc9-mm1-mmotm-2008-12-22-16-14-f2ab3dea #1
    RIP: 0010:[<ffffffff8028e710>]  [<ffffffff8028e710>] update_page_reclaim_stat+0x2f/0x42
    RSP: 0000:ffff8801ee457da8  EFLAGS: 00010002
    RAX: 32353438312021c8 RBX: 0000000000000000 RCX: 32353438312021c8
    RDX: 0000000000000000 RSI: ffff8800cb0b1000 RDI: ffff8801164d1d28
    RBP: ffff880110002cb8 R08: ffff88010f2eae23 R09: 0000000000000001
    R10: ffff8800bc514b00 R11: ffff880110002c00 R12: 0000000000000000
    R13: ffff88000f484100 R14: 0000000000000003 R15: 00000000001200d2
    FS:  00007f8a261726f0(0000) GS:ffff88010f2eaa80(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
    CR2: 00007f8a25d22000 CR3: 00000001ef18c000 CR4: 00000000000006e0
    DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
    Process page01 (pid: 26038, threadinfo ffff8801ee456000, task ffff8800b585b960)
    Stack:
     ffffe200071ee568 ffff880110001f00 0000000000000000 ffffffff8028ea17
     ffff88000f484100 0000000000000000 0000000000000020 00007f8a25d22000
     ffff8800bc514b00 ffffffff8028ec34 0000000000000000 0000000000016fd8
    Call Trace:
     [<ffffffff8028ea17>] ? ____pagevec_lru_add+0xc1/0x13c
     [<ffffffff8028ec34>] ? drain_cpu_pagevecs+0x36/0x89
     [<ffffffff802a4f8c>] ? swapin_readahead+0x78/0x98
     [<ffffffff8029a37a>] ? handle_mm_fault+0x3d9/0x741
     [<ffffffff804da654>] ? do_page_fault+0x3ce/0x78c
     [<ffffffff804d7a42>] ? trace_hardirqs_off_thunk+0x3a/0x3c
     [<ffffffff804d860f>] ? page_fault+0x1f/0x30
    Code: cc 55 48 8d af b8 0d 00 00 48 89 f7 53 89 d3 e8 39 85 02 00 48 63 d3 48 ff 44 d5 10 45 85 e4 74 05 48 ff 44 d5 00 48 85 c0 74 0e <48> ff 44 d0 10 45 85 e4 74 04 48 ff 04 d0 5b 5d 41 5c c3 41 54
    RIP  [<ffffffff8028e710>] update_page_reclaim_stat+0x2f/0x42
     RSP <ffff8801ee457da8>

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-15 16:39:39 -08:00
Ivan Kokshaysky
822c18f2e3 alpha: fix vmalloc breakage
On alpha, we have to map some stuff in the VMALLOC space very early in the
boot process (to make SRM console callbacks work and so on, see
arch/alpha/mm/init.c).  For old VM allocator, we just manually placed a
vm_struct onto the global vmlist and this worked for ages.

Unfortunately, the new allocator isn't aware of this, so it constantly
tries to allocate the VM space which is already in use, making vmalloc on
alpha defunct.

This patch forces KVA to import vmlist entries on init.

[akpm@linux-foundation.org: remove unneeded check (per Johannes)]
Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-15 16:39:35 -08:00
Heiko Carstens
938bb9f5e8 [CVE-2009-0029] System call wrappers part 28
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:30 +01:00
Heiko Carstens
c4ea37c26a [CVE-2009-0029] System call wrappers part 26
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:29 +01:00
Heiko Carstens
3480b25743 [CVE-2009-0029] System call wrappers part 14
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:24 +01:00
Heiko Carstens
6a6160a7b5 [CVE-2009-0029] System call wrappers part 13
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:23 +01:00
Heiko Carstens
6673e0c3fb [CVE-2009-0029] System call wrapper special cases
System calls with an unsigned long long argument can't be converted with
the standard wrappers since that would include a cast to long, which in
turn means that we would lose the upper 32 bit on 32 bit architectures.
Also semctl can't use the standard wrapper since it has a 'union'
parameter.

So we handle them as special case and add some extra wrappers instead.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:18 +01:00
Heiko Carstens
2ed7c03ec1 [CVE-2009-0029] Convert all system calls to return a long
Convert all system calls to return a long. This should be a NOP since all
converted types should have the same size anyway.
With the exception of sys_exit_group which returned void. But that doesn't
matter since the system call doesn't return.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:14 +01:00
venkatesh.pallipadi@intel.com
e4b866ed19 x86 PAT: change track_pfn_vma_new to take pgprot_t pointer param
Impact: cleanup

Change the protection parameter for track_pfn_vma_new() into a pgprot_t pointer.
Subsequent patch changes the x86 PAT handling to return a compatible
memtype in pgprot_t, if what was requested cannot be allowed due to conflicts.
No fuctionality change in this patch.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-13 19:13:01 +01:00
venkatesh.pallipadi@intel.com
a367061311 x86 PAT: remove PFNMAP type on track_pfn_vma_new() error
Impact: fix (harmless) double-free of memtype entries and avoid warning

On track_pfn_vma_new() failure, reset the vm_flags so that there will be
no second cleanup happening when upper level routines call unmap_vmas().

This patch fixes part of the bug reported here:

  http://marc.info/?l=linux-kernel&m=123108883716357&w=2

Specifically the error message:

  X:5010 freeing invalid memtype d0000000-d0101000

Is due to multiple frees on error path, will not happen with the patch below.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-13 19:12:59 +01:00
Peter Zijlstra
95156f0051 lockdep, mm: fix might_fault() annotation
Some code (nfs/sunrpc) uses socket ops on kernel memory while holding
the mmap_sem, this is safe because kernel memory doesn't get paged out,
therefore we'll never actually fault, and the might_fault() annotations
will generate false positives.

Reported-by: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-12 13:09:18 +01:00
Ingo Molnar
99cd707489 Merge commit 'v2.6.29-rc1' into tracing/urgent 2009-01-11 03:43:52 +01:00
Linus Torvalds
c40f6f8bbc Merge git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-nommu
* git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-nommu:
  NOMMU: Support XIP on initramfs
  NOMMU: Teach kobjsize() about VMA regions.
  FLAT: Don't attempt to expand the userspace stack to fill the space allocated
  FDPIC: Don't attempt to expand the userspace stack to fill the space allocated
  NOMMU: Improve procfs output using per-MM VMAs
  NOMMU: Make mmap allocation page trimming behaviour configurable.
  NOMMU: Make VMAs per MM as for MMU-mode linux
  NOMMU: Delete askedalloc and realalloc variables
  NOMMU: Rename ARM's struct vm_region
  NOMMU: Fix cleanup handling in ramfs_nommu_get_umapped_area()
2009-01-09 14:00:58 -08:00
Paul Menage
2cb378c862 cgroups: use hierarchy_mutex in memory controller
Update the memory controller to use its hierarchy_mutex rather than
calling cgroup_lock() to protected against cgroup_mkdir()/cgroup_rmdir()
from occurring in its hierarchy.

Signed-off-by: Paul Menage <menage@google.com>
Tested-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:10 -08:00
KAMEZAWA Hiroyuki
b5a84319a4 memcg: fix shmem's swap accounting
Now, you can see following even when swap accounting is enabled.

 1. Create Group 01, and 02.
 2. allocate a "file" on tmpfs by a task under 01.
 3. swap out the "file" (by memory pressure)
 4. Read "file" from a task in group 02.
 5. the charge of "file" is moved to group 02.

This is not ideal behavior. This is because SwapCache which was loaded
by read-ahead is not taken into account..

This is a patch to fix shmem's swapcache behavior.
  - remove mem_cgroup_cache_charge_swapin().
  - Add SwapCache handler routine to mem_cgroup_cache_charge().
    By this, shmem's file cache is charged at add_to_page_cache()
    with GFP_NOWAIT.
  - pass the page of swapcache to shrink_mem_cgroup.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:10 -08:00
KAMEZAWA Hiroyuki
544122e5e0 memcg: fix LRU accounting for SwapCache
Now, a page can be deleted from SwapCache while do_swap_page().
memcg-fix-swap-accounting-leak-v3.patch handles that, but, LRU handling is
still broken.  (above behavior broke assumption of memcg-synchronized-lru
patch.)

This patch is a fix for LRU handling (especially for per-zone counters).
At charging SwapCache,
 - Remove page_cgroup from LRU if it's not used.
 - Add page cgroup to LRU if it's not linked to.

Reported-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:10 -08:00
KAMEZAWA Hiroyuki
54595fe265 memcg: use css_tryget in memcg
From:KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>

css_tryget() newly is added and we can know css is alive or not and get
refcnt of css in very safe way.  ("alive" here means "rmdir/destroy" is
not called.)

This patch replaces css_get() to css_tryget(), where I cannot explain
why css_get() is safe. And removes memcg->obsolete flag.

Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:10 -08:00
KAMEZAWA Hiroyuki
a7ba0eef3a memcg: fix double free and make refcnt sane
1. Fix double-free BUG in error route of mem_cgroup_create().
    mem_cgroup_free() itself frees per-zone-info.
 2. Making refcnt of memcg simple.
    Add 1 refcnt at creation and call free when refcnt goes down to 0.

Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:10 -08:00
KAMEZAWA Hiroyuki
03f3c43364 memcg: fix swap accounting leak
Fix swapin charge operation of memcg.

Now, memcg has hooks to swap-out operation and checks SwapCache is really
unused or not.  That check depends on contents of struct page.  I.e.  If
PageAnon(page) && page_mapped(page), the page is recoginized as
still-in-use.

Now, reuse_swap_page() calles delete_from_swap_cache() before establishment
of any rmap. Then, in followinig sequence

	(Page fault with WRITE)
	try_charge() (charge += PAGESIZE)
	commit_charge() (Check page_cgroup is used or not..)
	reuse_swap_page()
		-> delete_from_swapcache()
			-> mem_cgroup_uncharge_swapcache() (charge -= PAGESIZE)
	......
New charge is uncharged soon....
To avoid this,  move commit_charge() after page_mapcount() goes up to 1.
By this,

	try_charge()		(usage += PAGESIZE)
	reuse_swap_page()	(may usage -= PAGESIZE if PCG_USED is set)
	commit_charge()		(If page_cgroup is not marked as PCG_USED,
				 add new charge.)
Accounting will be correct.

Changelog (v2) -> (v3)
  - fixed invalid charge to swp_entry==0.
  - updated documentation.
Changelog (v1) -> (v2)
  - fixed comment.

[nishimura@mxp.nes.nec.co.jp: swap accounting leak doc fix]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:10 -08:00
Daisuke Nishimura
42e9abb628 memcg: change try_to_free_pages to hierarchical_reclaim
mem_cgroup_hierarchicl_reclaim() works properly even when !use_hierarchy
now (by memcg-hierarchy-avoid-unnecessary-reclaim.patch), so, instead of
try_to_free_mem_cgroup_pages(), it should be used in many cases.

The only exception is force_empty.  The group has no children in this
case.

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: 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>
2009-01-08 08:31:09 -08:00
Daisuke Nishimura
7f4d454dee memcg: avoid deadlock caused by race between oom and cpuset_attach
mpol_rebind_mm(), which can be called from cpuset_attach(), does
down_write(mm->mmap_sem).  This means down_write(mm->mmap_sem) can be
called under cgroup_mutex.

OTOH, page fault path does down_read(mm->mmap_sem) and calls
mem_cgroup_try_charge_xxx(), which may eventually calls
mem_cgroup_out_of_memory().  And mem_cgroup_out_of_memory() calls
cgroup_lock().  This means cgroup_lock() can be called under
down_read(mm->mmap_sem).

If those two paths race, deadlock can happen.

This patch avoid this deadlock by:
  - remove cgroup_lock() from mem_cgroup_out_of_memory().
  - define new mutex (memcg_tasklist) and serialize mem_cgroup_move_task()
    (->attach handler of memory cgroup) and mem_cgroup_out_of_memory.

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: 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>
2009-01-08 08:31:09 -08:00
Daisuke Nishimura
a5e924f5f8 memcg: remove mem_cgroup_try_charge
After previous patch, mem_cgroup_try_charge is not used by anyone, so we
can remove it.

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:09 -08:00
Daisuke Nishimura
3bb4edf24b memcg: don't trigger oom at page migration
I think triggering OOM at mem_cgroup_prepare_migration would be just a bit
overkill.  Returning -ENOMEM would be enough for
mem_cgroup_prepare_migration.  The caller would handle the case anyway.

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: 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>
2009-01-08 08:31:09 -08:00
KAMEZAWA Hiroyuki
fee7b548e6 memcg: show real limit under hierarchy mode
Show "real" limit of memcg.  This helps my debugging and maybe useful for
users.

While testing hierarchy like this

	mount -t cgroup none /cgroup -t memory
	mkdir /cgroup/A
	set use_hierarchy==1 to "A"
	mkdir /cgroup/A/01
	mkdir /cgroup/A/01/02
	mkdir /cgroup/A/01/03
	mkdir /cgroup/A/01/03/04
	mkdir /cgroup/A/08
	mkdir /cgroup/A/08/01
	....
and set each own limit to them, "real" limit of each memcg is unclear.
This patch shows real limit by checking all ancestors.

Changelog: (v1) -> (v2)
	- remove "if" and use "min(a,b)"

Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:09 -08:00
KOSAKI Motohiro
c772be939e memcg: fix calculation of active_ratio
Currently, inactive_ratio of memcg is calculated at setting limit.
because page_alloc.c does so and current implementation is straightforward
porting.

However, memcg introduced hierarchy feature recently.  In hierarchy
restriction, memory limit is not only decided memory.limit_in_bytes of
current cgroup, but also parent limit and sibling memory usage.

Then, The optimal inactive_ratio is changed frequently.  So, everytime
calculation is better.

Tested-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
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>
2009-01-08 08:31:09 -08:00
KOSAKI Motohiro
a7885eb8ad memcg: swappiness
Currently, /proc/sys/vm/swappiness can change swappiness ratio for global
reclaim.  However, memcg reclaim doesn't have tuning parameter for itself.

In general, the optimal swappiness depend on workload.  (e.g.  hpc
workload need to low swappiness than the others.)

Then, per cgroup swappiness improve administrator tunability.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:08 -08:00
KOSAKI Motohiro
2733c06ac8 memcg: protect prev_priority
Currently, mem_cgroup doesn't have own lock and almost its member doesn't
need.  (e.g.  mem_cgroup->info is protected by zone lock, mem_cgroup->stat
is per cpu variable)

However, there is one explict exception.  mem_cgroup->prev_priorit need
lock, but doesn't protect.  Luckly, this is NOT bug because prev_priority
isn't used for current reclaim code.

However, we plan to use prev_priority future again.  Therefore, fixing is
better.

In addition, we plan to reuse this lock for another member.  Then
"reclaim_param_lock" name is better than "prev_priority_lock".

Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:08 -08:00
KAMEZAWA Hiroyuki
e72e2bd674 memcg: rename scan global lru
Rename scan_global_lru() to scanning_global_lru().

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:08 -08:00
KOSAKI Motohiro
7f016ee8b6 memcg: show reclaim stat
Add the following four fields to memory.stat file:

  - inactive_ratio
  - recent_rotated_anon
  - recent_rotated_file
  - recent_scanned_anon
  - recent_scanned_file

Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:08 -08:00
KOSAKI Motohiro
9439c1c95b memcg: remove mem_cgroup_cal_reclaim()
Now, get_scan_ratio() return correct value although memcg reclaim.  Then,
mem_cgroup_calc_reclaim() can be removed.

So, memcg reclaim get the same capability of anon/file reclaim balancing
as global reclaim now.

Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:08 -08:00
KOSAKI Motohiro
3e2f41f1f6 memcg: add zone_reclaim_stat
Introduce mem_cgroup_per_zone::reclaim_stat member and its statics
collecting function.

Now, get_scan_ratio() can calculate correct value on memcg reclaim.

[hugh@veritas.com: avoid reclaim_stat oops when disabled]
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:08 -08:00
KOSAKI Motohiro
a3d8e0549d memcg: add mem_cgroup_zone_nr_pages()
Introduce mem_cgroup_zone_nr_pages().  It is called by zone_nr_pages()
helper function.

This patch doesn't have any behavior change.

Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:08 -08:00
KOSAKI Motohiro
14797e2363 memcg: add inactive_anon_is_low()
The inactive_anon_is_low() is key component of active/inactive anon
balancing on reclaim.  However current inactive_anon_is_low() function
only consider global reclaim.

Therefore, we need following ugly scan_global_lru() condition.

	if (lru == LRU_ACTIVE_ANON &&
	    (!scan_global_lru(sc) || inactive_anon_is_low(zone))) {
		shrink_active_list(nr_to_scan, zone, sc, priority, file);
		return 0;

it cause that memcg reclaim always deactivate pages when shrink_list() is
called.  To make mem_cgroup_inactive_anon_is_low() improve active/inactive
anon balancing of memcgroup.

Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: "Pekka Enberg" <penberg@cs.helsinki.fi>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:08 -08:00
KOSAKI Motohiro
549927620b memcg: add null check to page_cgroup_zoneinfo()
If CONFIG_CGROUP_MEM_RES_CTLR_SWAP=y, page_cgroup::mem_cgroup can be NULL.
Therefore null checking is better.

A later patch uses this function.

Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:07 -08:00
KOSAKI Motohiro
eeee9a8cd1 mm: make get_scan_ratio() safe for memcg
Currently, get_scan_ratio() always calculate the balancing value for
global reclaim and memcg reclaim doesn't use it.  Therefore it doesn't
have scan_global_lru() condition.

However, we plan to expand get_scan_ratio() to be usable for memcg too,
latter.  Then, The dependency code of global reclaim in the
get_scan_ratio() insert into scan_global_lru() condision explictly.

This patch doesn't have any functional change.

Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:07 -08:00
KOSAKI Motohiro
c9f299d986 mm: add zone nr_pages helper function
Add zone_nr_pages() helper function.

It is used by a later patch.  This patch doesn't have any functional
change.

Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:07 -08:00
KOSAKI Motohiro
6e9015716a mm: introduce zone_reclaim struct
Add zone_reclam_stat struct for later enhancement.

A later patch uses this.  This patch doesn't any behavior change (yet).

Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:07 -08:00
KOSAKI Motohiro
f89eb90e33 inactive_anon_is_low: move to vmscan
The inactive_anon_is_low() is called only vmscan.  Then it can move to
vmscan.c

This patch doesn't have any functional change.

Reviewd-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:07 -08:00
Daisuke Nishimura
670ec2f170 memcg: hierarchy avoid unnecessary reclaim
If hierarchy is not used, no tree-walk is necessary.

Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:07 -08:00
KAMEZAWA Hiroyuki
a7fe942e94 memcg: swapout refcnt fix
css's refcnt is dropped before end of following access.
Hold it until end of access.

Reported-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:07 -08:00
Daisuke Nishimura
b85a96c0b6 memcg: memory swap controller: fix limit check
There are scatterd calls of res_counter_check_under_limit(), and most of
them don't take mem+swap accounting into account.

define mem_cgroup_check_under_limit() and avoid direct use of
res_counter_check_limit().

Reported-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:07 -08:00
Nikanth Karthikesan
f9717d28d6 memcg: check group leader fix
Remove unnecessary codes (...fragments of not-implemented
functionalilty...)

Reported-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:06 -08:00
KAMEZAWA Hiroyuki
2c26fdd70c memcg: revert gfp mask fix
My patch, memcg-fix-gfp_mask-of-callers-of-charge.patch changed gfp_mask
of callers of charge to be GFP_HIGHUSER_MOVABLE for showing what will
happen at memory reclaim.

But in recent discussion, it's NACKed because it sounds ugly.

This patch is for reverting it and add some clean up to gfp_mask of
callers of charge.  No behavior change but need review before generating
HUNK in deep queue.

This patch also adds explanation to meaning of gfp_mask passed to charge
functions in memcontrol.h.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:06 -08:00
KAMEZAWA Hiroyuki
887007561a memcg: fix reclaim result checks
check_under_limit logic was wrong and this check should be against
mem_over_limit rather than mem.

Reported-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Jan Blunck <jblunck@suse.de>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:06 -08:00
KAMEZAWA Hiroyuki
a636b327f7 memcg: avoid unnecessary system-wide-oom-killer
Current mmtom has new oom function as pagefault_out_of_memory().  It's
added for select bad process rathar than killing current.

When memcg hit limit and calls OOM at page_fault, this handler called and
system-wide-oom handling happens.  (means kernel panics if panic_on_oom is
true....)

To avoid overkill, check memcg's recent behavior before starting
system-wide-oom.

And this patch also fixes to guarantee "don't accnout against process with
TIF_MEMDIE".  This is necessary for smooth OOM.

[akpm@linux-foundation.org: build fix]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Jan Blunck <jblunck@suse.de>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:06 -08:00
Balbir Singh
18f59ea7de memcg: memory cgroup hierarchy feature selector
Don't enable multiple hierarchy support by default.  This patch introduces
a features element that can be set to enable the nested depth hierarchy
feature.  This feature can only be enabled when the cgroup for which the
feature this is enabled, has no children.

Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
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>
2009-01-08 08:31:06 -08:00