Commit Graph

2778 Commits

Author SHA1 Message Date
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
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
Balbir Singh 6d61ef409d memcg: memory cgroup hierarchical reclaim
This patch introduces hierarchical reclaim.  When an ancestor goes over
its limit, the charging routine points to the parent that is above its
limit.  The reclaim process then starts from the last scanned child of the
ancestor and reclaims until the ancestor goes below its limit.

[akpm@linux-foundation.org: coding-style fixes]
[d-nishimura@mtf.biglobe.ne.jp: mem_cgroup_from_res_counter should handle both mem->res and mem->memsw]
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: 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 08:31:06 -08:00
Balbir Singh 28dbc4b6a0 memcg: memory cgroup resource counters for hierarchy
Add support for building hierarchies in resource counters.  Cgroups allows
us to build a deep hierarchy, but we currently don't link the resource
counters belonging to the memory controller control groups, in the same
fashion as the corresponding cgroup entries in the cgroup hierarchy.  This
patch provides the infrastructure for resource counters that have the same
hiearchy as their cgroup counter parts.

These set of patches are based on the resource counter hiearchy patches
posted by Pavel Emelianov.

NOTE: Building hiearchies is expensive, deeper hierarchies imply charging
the all the way up to the root.  It is known that hiearchies are
expensive, so the user needs to be careful and aware of the trade-offs
before creating very deep ones.

[akpm@linux-foundation.org: coding-style fixes]
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 08:31:05 -08:00
Hirokazu Takahashi f8d6654226 memcg: add mem_cgroup_disabled()
We check mem_cgroup is disabled or not by checking
mem_cgroup_subsys.disabled.  I think it has more references than expected,
now.

replacing
   if (mem_cgroup_subsys.disabled)
with
   if (mem_cgroup_disabled())

give us good look, I think.

[kamezawa.hiroyu@jp.fujitsu.com: fix typo]
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: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:05 -08:00
KAMEZAWA Hiroyuki 08e552c69c memcg: synchronized LRU
A big patch for changing memcg's LRU semantics.

Now,
  - page_cgroup is linked to mem_cgroup's its own LRU (per zone).

  - LRU of page_cgroup is not synchronous with global LRU.

  - page and page_cgroup is one-to-one and statically allocated.

  - To find page_cgroup is on what LRU, you have to check pc->mem_cgroup as
    - lru = page_cgroup_zoneinfo(pc, nid_of_pc, zid_of_pc);

  - SwapCache is handled.

And, when we handle LRU list of page_cgroup, we do following.

	pc = lookup_page_cgroup(page);
	lock_page_cgroup(pc); .....................(1)
	mz = page_cgroup_zoneinfo(pc);
	spin_lock(&mz->lru_lock);
	.....add to LRU
	spin_unlock(&mz->lru_lock);
	unlock_page_cgroup(pc);

But (1) is spin_lock and we have to be afraid of dead-lock with zone->lru_lock.
So, trylock() is used at (1), now. Without (1), we can't trust "mz" is correct.

This is a trial to remove this dirty nesting of locks.
This patch changes mz->lru_lock to be zone->lru_lock.
Then, above sequence will be written as

        spin_lock(&zone->lru_lock); # in vmscan.c or swap.c via global LRU
	mem_cgroup_add/remove/etc_lru() {
		pc = lookup_page_cgroup(page);
		mz = page_cgroup_zoneinfo(pc);
		if (PageCgroupUsed(pc)) {
			....add to LRU
		}
        spin_lock(&zone->lru_lock); # in vmscan.c or swap.c via global LRU

This is much simpler.
(*) We're safe even if we don't take lock_page_cgroup(pc). Because..
    1. When pc->mem_cgroup can be modified.
       - at charge.
       - at account_move().
    2. at charge
       the PCG_USED bit is not set before pc->mem_cgroup is fixed.
    3. at account_move()
       the page is isolated and not on LRU.

Pros.
  - easy for maintenance.
  - memcg can make use of laziness of pagevec.
  - we don't have to duplicated LRU/Active/Unevictable bit in page_cgroup.
  - LRU status of memcg will be synchronized with global LRU's one.
  - # of locks are reduced.
  - account_move() is simplified very much.
Cons.
  - may increase cost of LRU rotation.
    (no impact if memcg is not configured.)

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: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:05 -08:00