29 May, 2009
2 commits
-
Fix build warning, "mem_cgroup_is_obsolete defined but not used" when
CONFIG_DEBUG_VM is not set. Also avoid checking for !mem again and again.Signed-off-by: Nikanth Karthikesan
Acked-by: Pekka Enberg
Acked-by: KAMEZAWA Hiroyuki
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
mapping->tree_lock can be acquired from interrupt context. Then,
following dead lock can occur.Assume "A" as a page.
CPU0:
lock_page_cgroup(A)
interrupted
-> take mapping->tree_lock.
CPU1:
take mapping->tree_lock
-> lock_page_cgroup(A)This patch tries to fix above deadlock by moving memcg's hook to out of
mapping->tree_lock. charge/uncharge of pagecache/swapcache is protected
by page lock, not tree_lock.After this patch, lock_page_cgroup() is not called under mapping->tree_lock.
Signed-off-by: KAMEZAWA Hiroyuki
Signed-off-by: Daisuke Nishimura
Cc: Balbir Singh
Cc: Daisuke Nishimura
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
03 May, 2009
2 commits
-
Current mem_cgroup_shrink_usage() has two problems.
1. It doesn't call mem_cgroup_out_of_memory and doesn't update
last_oom_jiffies, so pagefault_out_of_memory invokes global OOM.2. Considering hierarchy, shrinking has to be done from the
mem_over_limit, not from the memcg which the page would be charged to.mem_cgroup_try_charge_swapin() does all of these things properly, so we
use it and call cancel_charge_swapin when it succeeded.The name of "shrink_usage" is not appropriate for this behavior, so we
change it too.Signed-off-by: Daisuke Nishimura
Acked-by: KAMEZAWA Hiroyuki
Cc: Li Zefan
Cc: Paul Menage
Cc: Dhaval Giani
Cc: Daisuke Nishimura
Cc: YAMAMOTO Takashi
Cc: KOSAKI Motohiro
Cc: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This is a bugfix for commit 3c776e64660028236313f0e54f3a9945764422df
("memcg: charge swapcache to proper memcg").Used bit of swapcache is solid under page lock, but considering
move_account, pc->mem_cgroup is not.We need lock_page_cgroup() anyway.
Signed-off-by: Daisuke Nishimura
Acked-by: KAMEZAWA Hiroyuki
Cc: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
14 Apr, 2009
1 commit
-
mm/memcontrol.c:318: warning: `mem_cgroup_is_obsolete' defined but not used
[akpm@linux-foundation.org: simplify as suggested by Balbir]
Signed-off-by: KAMEZAWA Hiroyuki
Reviewed-by: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
03 Apr, 2009
10 commits
-
Current mem_cgroup_cache_charge is a bit complicated especially
in the case of shmem's swap-in.This patch cleans it up by using try_charge_swapin and commit_charge_swapin.
Signed-off-by: Daisuke Nishimura
Acked-by: KAMEZAWA Hiroyuki
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Try to use CSS ID for records in swap_cgroup. By this, on 64bit machine,
size of swap_cgroup goes down to 2 bytes from 8bytes.This means, when 2GB of swap is equipped, (assume the page size is 4096bytes)
From size of swap_cgroup = 2G/4k * 8 = 4Mbytes.
To size of swap_cgroup = 2G/4k * 2 = 1Mbytes.Reduction is large. Of course, there are trade-offs. This CSS ID will
add overhead to swap-in/swap-out/swap-free.But in general,
- swap is a resource which the user tend to avoid use.
- If swap is never used, swap_cgroup area is not used.
- Reading traditional manuals, size of swap should be proportional to
size of memory. Memory size of machine is increasing now.I think reducing size of swap_cgroup makes sense.
Note:
- ID->CSS lookup routine has no locks, it's under RCU-Read-Side.
- memcg can be obsolete at rmdir() but not freed while refcnt from
swap_cgroup is available.Changelog v4->v5:
- reworked on to memcg-charge-swapcache-to-proper-memcg.patch
Changlog ->v4:
- fixed not configured case.
- deleted unnecessary comments.
- fixed NULL pointer bug.
- fixed message in dmesg.[nishimura@mxp.nes.nec.co.jp: css_tryget can be called twice in !PageCgroupUsed case]
Signed-off-by: KAMEZAWA Hiroyuki
Cc: Li Zefan
Cc: Balbir Singh
Cc: Paul Menage
Cc: Hugh Dickins
Signed-off-by: Daisuke Nishimura
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
memcg_test.txt says at 4.1:
This swap-in is one of the most complicated work. In do_swap_page(),
following events occur when pte is unchanged.(1) the page (SwapCache) is looked up.
(2) lock_page()
(3) try_charge_swapin()
(4) reuse_swap_page() (may call delete_swap_cache())
(5) commit_charge_swapin()
(6) swap_free().Considering following situation for example.
(A) The page has not been charged before (2) and reuse_swap_page()
doesn't call delete_from_swap_cache().
(B) The page has not been charged before (2) and reuse_swap_page()
calls delete_from_swap_cache().
(C) The page has been charged before (2) and reuse_swap_page() doesn't
call delete_from_swap_cache().
(D) The page has been charged before (2) and reuse_swap_page() calls
delete_from_swap_cache().memory.usage/memsw.usage changes to this page/swp_entry will be
Case (A) (B) (C) (D)
Event
Before (2) 0/ 1 0/ 1 1/ 1 1/ 1
===========================================
(3) +1/+1 +1/+1 +1/+1 +1/+1
(4) - 0/ 0 - -1/ 0
(5) 0/-1 0/ 0 -1/-1 0/ 0
(6) - 0/-1 - 0/-1
===========================================
Result 1/ 1 1/ 1 1/ 1 1/ 1In any cases, charges to this page should be 1/ 1.
In case of (D), mem_cgroup_try_get_from_swapcache() returns NULL
(because lookup_swap_cgroup() returns NULL), so "+1/+1" at (3) means
charges to the memcg("foo") to which the "current" belongs.
OTOH, "-1/0" at (4) and "0/-1" at (6) means uncharges from the memcg("baa")
to which the page has been charged.So, if the "foo" and "baa" is different(for example because of task move),
this charge will be moved from "baa" to "foo".I think this is an unexpected behavior.
This patch fixes this by modifying mem_cgroup_try_get_from_swapcache()
to return the memcg to which the swapcache has been charged if PCG_USED bit
is set.
IIUC, checking PCG_USED bit of swapcache is safe under page lock.Signed-off-by: Daisuke Nishimura
Cc: Balbir Singh
Cc: KAMEZAWA Hiroyuki
Cc: Li Zefan
Cc: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Currently, mem_cgroup_calc_mapped_ratio() is unused at all. it can be
removed and KAMEZAWA-san suggested it.Signed-off-by: KOSAKI Motohiro
Cc: KAMEZAWA Hiroyuki
Acked-by: Balbir Singh
Cc: Johannes Weiner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add RSS and swap to OOM output from memcg
Display memcg values like failcnt, usage and limit when an OOM occurs due
to memcg.Thanks to Johannes Weiner, Li Zefan, David Rientjes, Kamezawa Hiroyuki,
Daisuke Nishimura and KOSAKI Motohiro for review.Sample output
-------------Task in /a/x killed as a result of limit of /a
memory: usage 1048576kB, limit 1048576kB, failcnt 4183
memory+swap: usage 1400964kB, limit 9007199254740991kB, failcnt 0[akpm@linux-foundation.org: compilation fix]
[akpm@linux-foundation.org: fix kerneldoc and whitespace]
[akpm@linux-foundation.org: add printk facility level]
Signed-off-by: Balbir Singh
Cc: KAMEZAWA Hiroyuki
Cc: Daisuke Nishimura
Cc: Li Zefan
Cc: Paul Menage
Cc: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch tries to fix OOM Killer problems caused by hierarchy.
Now, memcg itself has OOM KILL function (in oom_kill.c) and tries to
kill a task in memcg.But, when hierarchy is used, it's broken and correct task cannot
be killed. For example, in following cgroup/groupA/ hierarchy=1, limit=1G,
01 nolimit
02 nolimit
All tasks' memory usage under /groupA, /groupA/01, groupA/02 is limited to
groupA's 1Gbytes but OOM Killer just kills tasks in groupA.This patch provides makes the bad process be selected from all tasks
under hierarchy. BTW, currently, oom_jiffies is updated against groupA
in above case. oom_jiffies of tree should be updated.To see how oom_jiffies is used, please check mem_cgroup_oom_called()
callers.[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: const fix]
Signed-off-by: KAMEZAWA Hiroyuki
Cc: Paul Menage
Cc: Li Zefan
Cc: Balbir Singh
Cc: Daisuke Nishimura
Cc: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
As pointed out, shrinking memcg's limit should return -EBUSY after
reasonable retries. This patch tries to fix the current behavior of
shrink_usage.Before looking into "shrink should return -EBUSY" problem, we should fix
hierarchical reclaim code. It compares current usage and current limit,
but it only makes sense when the kernel reclaims memory because hit
limits. This is also a problem.What this patch does are.
1. add new argument "shrink" to hierarchical reclaim. If "shrink==true",
hierarchical reclaim returns immediately and the caller checks the kernel
should shrink more or not.
(At shrinking memory, usage is always smaller than limit. So check for
usage < limit is useless.)2. For adjusting to above change, 2 changes in "shrink"'s retry path.
2-a. retry_count depends on # of children because the kernel visits
the children under hierarchy one by one.
2-b. rather than checking return value of hierarchical_reclaim's progress,
compares usage-before-shrink and usage-after-shrink.
If usage-before-shrink
Signed-off-by: KAMEZAWA Hiroyuki
Cc: Paul Menage
Cc: Balbir Singh
Cc: Daisuke Nishimura
Cc: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Clean up memory.stat file routine and show "total" hierarchical stat.
This patch does
- renamed get_all_zonestat to be get_local_zonestat.
- remove old mem_cgroup_stat_desc, which is only for per-cpu stat.
- add mcs_stat to cover both of per-cpu/per-lru stat.
- add "total" stat of hierarchy (*)
- add a callback system to scan all memcg under a root.
== "total" is added.
[kamezawa@localhost ~]$ cat /opt/cgroup/xxx/memory.stat
cache 0
rss 0
pgpgin 0
pgpgout 0
inactive_anon 0
active_anon 0
inactive_file 0
active_file 0
unevictable 0
hierarchical_memory_limit 50331648
hierarchical_memsw_limit 9223372036854775807
total_cache 65536
total_rss 192512
total_pgpgin 218
total_pgpgout 155
total_inactive_anon 0
total_active_anon 135168
total_inactive_file 61440
total_active_file 4096
total_unevictable 0
==
(*) maybe the user can do calc hierarchical stat by his own program
in userland but if it can be written in clean way, it's worth to be
shown, I think.Signed-off-by: KAMEZAWA Hiroyuki
Cc: Paul Menage
Cc: Li Zefan
Cc: Balbir Singh
Cc: Daisuke Nishimura
Cc: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Assigning CSS ID for each memcg and use css_get_next() for scanning hierarchy.
Assume folloing tree.
group_A (ID=3)
/01 (ID=4)
/0A (ID=7)
/02 (ID=10)
group_B (ID=5)
and task in group_A/01/0A hits limit at group_A.reclaim will be done in following order (round-robin).
group_A(3) -> group_A/01 (4) -> group_A/01/0A (7) -> group_A/02(10)
-> group_A -> .....Round robin by ID. The last visited cgroup is recorded and restart
from it when it start reclaim again.
(More smart algorithm can be implemented..)No cgroup_mutex or hierarchy_mutex is required.
Signed-off-by: KAMEZAWA Hiroyuki
Cc: Paul Menage
Cc: Li Zefan
Cc: Balbir Singh
Cc: Daisuke Nishimura
Cc: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
In following situation, with memory subsystem,
/groupA use_hierarchy==1
/01 some tasks
/02 some tasks
/03 some tasks
/04 emptyWhen tasks under 01/02/03 hit limit on /groupA, hierarchical reclaim
is triggered and the kernel walks tree under groupA. In this case,
rmdir /groupA/04 fails with -EBUSY frequently because of temporal
refcnt from the kernel.In general. cgroup can be rmdir'd if there are no children groups and
no tasks. Frequent fails of rmdir() is not useful to users.
(And the reason for -EBUSY is unknown to users.....in most cases)This patch tries to modify above behavior, by
- retries if css_refcnt is got by someone.
- add "return value" to pre_destroy() and allows subsystem to
say "we're really busy!"Signed-off-by: KAMEZAWA Hiroyuki
Cc: Paul Menage
Cc: Li Zefan
Cc: Balbir Singh
Cc: Daisuke Nishimura
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
30 Jan, 2009
2 commits
-
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
Signed-off-by: KAMEZAWA Hiroyuki
Tested-by: Li Zefan
Cc: Balbir Singh
Cc: Daisuke Nishimura
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Reviewed-by; KAMEZAWA Hiroyuki
Cc: Balbir Singh
Cc: Pavel Emelyanov
Cc: Li Zefan
Cc: Paul Menage
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
16 Jan, 2009
6 commits
-
(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
Acked-by: KAMEZAWA Hiroyuki
Cc: Balbir Singh
Cc: Paul Menage
Cc: Daisuke Nishimura
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Li Zefan
Acked-by; KAMEZAWA Hiroyuki
Cc: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Acked-by: Balbir Singh
Acked-by: KAMEZAWA Hiroyuki
Cc: Pavel Emelyanov
Cc: Li Zefan
Cc: Paul Menage
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Cc: Balbir Singh
Cc: KAMEZAWA Hiroyuki
Cc: Pavel Emelyanov
Cc: Li Zefan
Cc: Paul Menage
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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_pageThis 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
Acked-by: KAMEZAWA Hiroyuki
Acked-by: Balbir Singh
Cc: Pavel Emelyanov
Cc: Li Zefan
Cc: Paul Menage
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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:[] [] 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:
[] ? ____pagevec_lru_add+0xc1/0x13c
[] ? drain_cpu_pagevecs+0x36/0x89
[] ? swapin_readahead+0x78/0x98
[] ? handle_mm_fault+0x3d9/0x741
[] ? do_page_fault+0x3ce/0x78c
[] ? trace_hardirqs_off_thunk+0x3a/0x3c
[] ? 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 ff 44 d0 10 45 85 e4 74 04 48 ff 04 d0 5b 5d 41 5c c3 41 54
RIP [] update_page_reclaim_stat+0x2f/0x42
RSPSigned-off-by: Daisuke Nishimura
Acked-by: KAMEZAWA Hiroyuki
Cc: Balbir Singh
Cc: Pavel Emelyanov
Cc: Li Zefan
Cc: Paul Menage
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 Jan, 2009
17 commits
-
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
Tested-by: KAMEZAWA Hiroyuki
Cc: Li Zefan
Cc: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Cc: Daisuke Nishimura
Cc: Balbir Singh
Cc: Paul Menage
Cc: Li Zefan
Cc: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: KAMEZAWA Hiroyuki
Cc: Balbir Singh
Cc: Paul Menage
Cc: Li Zefan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
From:KAMEZAWA Hiroyuki
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
Signed-off-by: KAMEZAWA Hiroyuki
Cc: Balbir Singh
Cc: Paul Menage
Cc: Daisuke Nishimura
Cc: Li Zefan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: KAMEZAWA Hiroyuki
Cc: Balbir Singh
Cc: Paul Menage
Cc: Daisuke Nishimura
Cc: Li Zefan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Acked-by: Balbir Singh
Tested-by: Balbir Singh
Cc: Hugh Dickins
Cc: Daisuke Nishimura
Signed-off-by: Daisuke Nishimura
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Acked-by: KAMEZAWA Hiroyuki
Acked-by: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Reviewed-by: KAMEZAWA Hiroyuki
Acked-by: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
After previous patch, mem_cgroup_try_charge is not used by anyone, so we
can remove it.Signed-off-by: Daisuke Nishimura
Acked-by: KAMEZAWA Hiroyuki
Cc: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Acked-by: KAMEZAWA Hiroyuki
Acked-by: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: KAMEZAWA Hiroyuki
Cc: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Acked-by: KAMEZAWA Hiroyuki
Signed-off-by: KOSAKI Motohiro
Cc: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: KOSAKI Motohiro
Cc: Balbir Singh
Cc: Daisuke Nishimura
Cc: Hugh Dickins
Cc: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: KOSAKI Motohiro
Cc: Balbir Singh
Cc: Daisuke Nishimura
Cc: Hugh Dickins
Cc: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add the following four fields to memory.stat file:
- inactive_ratio
- recent_rotated_anon
- recent_rotated_file
- recent_scanned_anon
- recent_scanned_fileAcked-by: Rik van Riel
Signed-off-by: KAMEZAWA Hiroyuki
Signed-off-by: KOSAKI Motohiro
Cc: Balbir Singh
Cc: Daisuke Nishimura
Cc: Hugh Dickins
Cc: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Acked-by: Rik van Riel
Signed-off-by: KOSAKI Motohiro
Cc: Balbir Singh
Cc: Daisuke Nishimura
Cc: Hugh Dickins
Cc: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Acked-by: Rik van Riel
Signed-off-by: KOSAKI Motohiro
Cc: Balbir Singh
Cc: Daisuke Nishimura
Cc: Hugh Dickins
Cc: KOSAKI Motohiro
Signed-off-by: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
