(2012/11/09 0:52), Sha Zhengju wrote:
> From: Sha Zhengju <handai.szj@xxxxxxxxxx>
>
> Current when a memcg oom is happening the oom dump messages is still global
> state and provides few useful info for users. This patch prints more pointed
> memcg page statistics for memcg-oom.
>
>
> We set up a simple cgroup hierarchy for test:
> root_memcg
> |
> 1 (use_hierachy=1, with a process)
> |
> 2 (its process will be killed by memcg oom)
>
> Following are samples of oom output:
>
> (1)Before change:
>
> [ 295.754215] mal invoked oom-killer: gfp_mask=0xd0, order=0, oom_score_adj=0
> [ 295.754219] mal cpuset=/ mems_allowed=0-1
> [ 295.754221] Pid: 4623, comm: mal Not tainted 3.6.0+ #26
> [ 295.754223] Call Trace:
> [ 295.754230] [<ffffffff8111b9c4>] dump_header+0x84/0xd0
> [ 295.754233] [<ffffffff8111c691>] oom_kill_process+0x331/0x350
> ..... (call trace)
> [ 295.754288] [<ffffffff815171e5>] page_fault+0x25/0x30
> [ 295.754291] Task in /1/2 killed as a result of limit of /1
> [ 295.754293] memory: usage 511640kB, limit 512000kB, failcnt 4471
> [ 295.754294] memory+swap: usage 563200kB, limit 563200kB, failcnt 22
> [ 295.754296] kmem: usage 0kB, limit 9007199254740991kB, failcnt 0
> [ 295.754297] Mem-Info:
> [ 295.754298] Node 0 DMA per-cpu: <<<<<<<<<<<<<<<<<<<<< print per cpu pageset stat
> [ 295.754300] CPU 0: hi: 0, btch: 1 usd: 0
> ......
> [ 295.754302] CPU 15: hi: 0, btch: 1 usd: 0
>
> [ 295.754448] Node 0 DMA32 per-cpu:
> [ 295.754450] CPU 0: hi: 186, btch: 31 usd: 181
> ......
> [ 295.754451] CPU 15: hi: 186, btch: 31 usd: 25
>
> [ 295.754470] Node 0 Normal per-cpu:
> [ 295.754472] CPU 0: hi: 186, btch: 31 usd: 56
> ......
> [ 295.754473] CPU 15: hi: 186, btch: 31 usd: 150
>
> [ 295.754493] Node 1 Normal per-cpu:
> [ 295.754495] CPU 0: hi: 186, btch: 31 usd: 0
> ......
> [ 295.754496] CPU 15: hi: 186, btch: 31 usd: 0
> <<<<<<<<<<<<<<<<<<<<< print global page state
> [ 295.754519] active_anon:57756 inactive_anon:73437 isolated_anon:0
> [ 295.754519] active_file:2659 inactive_file:14291 isolated_file:0
> [ 295.754519] unevictable:1268 dirty:0 writeback:4961 unstable:0
> [ 295.754519] free:5979740 slab_reclaimable:2955 slab_unreclaimable:5460
> [ 295.754519] mapped:2478 shmem:62 pagetables:994 bounce:0
> [ 295.754519] free_cma:0
> <<<<<<<<<<<<<<<<<<<<< print per zone page state
> [ 295.754522] Node 0 DMA free:15884kB min:56kB low:68kB high:84kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:15884kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no
> [ 295.754527] lowmem_reserve[]: 0 2966 12013 12013
> [ 295.754530] Node 0 DMA32 free:3041228kB min:11072kB .....
> [ 295.754535] lowmem_reserve[]: 0 0 9046 9046
> [ 295.754537] Node 0 Normal free:8616716kB min:33756kB .....
> [ 295.754542] lowmem_reserve[]: 0 0 0 0
> [ 295.754545] Node 1 Normal free:12245132kB min:45220kB ....
> [ 295.754550] lowmem_reserve[]: 0 0 0 0
> [ 295.754552] Node 0 DMA: 1*4kB (U) 1*8kB (U) 0*16kB 0*32kB 2*64kB (U) 1*128kB (U) 1*256kB (U) 0*512kB 1*1024kB (U) 1*2048kB (R) 3*4096kB (M) = 15884kB
> [ 295.754563] Node 0 DMA32: 5*4kB (M) 3*8kB (M) 6*16kB (UM) ... 738*4096kB (MR) = 3041228kB
> [ 295.754574] Node 0 Normal: 16*4kB (EM) 165*8kB (UEM) ... 2101*4096kB (MR) = 8616840kB
> [ 295.754586] Node 1 Normal: 768*4kB (UEM) 924*8kB (UEM) ... 048kB (EM) 2976*4096kB (MR) = 12245264kB
> [ 295.754598] 25266 total pagecache pages
> [ 295.754599] 7227 pages in swap cache
> <<<<<<<<<<<<<<<<<<<<< print global swap cache stat
> [ 295.754600] Swap cache stats: add 21474, delete 14247, find 533/576
> [ 295.754601] Free swap = 2016000kB
> [ 295.754602] Total swap = 2096444kB
> [ 295.816119] 6291440 pages RAM
> [ 295.816121] 108291 pages reserved
> [ 295.816122] 9427 pages shared
> [ 295.816123] 195843 pages non-shared
> [ 295.816124] [ pid ] uid tgid total_vm rss nr_ptes swapents oom_score_adj name
> [ 295.816161] [ 4569] 0 4569 16626 475 18 30 0 bash
> [ 295.816164] [ 4622] 0 4622 103328 87541 208 14950 0 mal
> [ 295.816167] [ 4623] 0 4623 103328 33468 85 5162 0 mal
> [ 295.816171] Memory cgroup out of memory: Kill process 4622 (mal) score 699 or sacrifice child
> [ 295.816173] Killed process 4622 (mal) total-vm:413312kB, anon-rss:349872kB, file-rss:292kB
>
> We can see that messages dumped by show_free_areas() are longsome and can provide so limited info for memcg that just happen oom.
>
> (2) After change
> [ 269.225628] mal invoked oom-killer: gfp_mask=0xd0, order=0, oom_score_adj=0
> [ 269.225633] mal cpuset=/ mems_allowed=0-1
> [ 269.225636] Pid: 4616, comm: mal Not tainted 3.6.0+ #25
> [ 269.225637] Call Trace:
> [ 269.225647] [<ffffffff8111b9c4>] dump_header+0x84/0xd0
> [ 269.225650] [<ffffffff8111c691>] oom_kill_process+0x331/0x350
> [ 269.225710] .......(call trace)
> [ 269.225713] [<ffffffff81517325>] page_fault+0x25/0x30
> [ 269.225716] Task in /1/2 killed as a result of limit of /1
> [ 269.225718] memory: usage 511732kB, limit 512000kB, failcnt 5071
> [ 269.225720] memory+swap: usage 563200kB, limit 563200kB, failcnt 57
> [ 269.225721] kmem: usage 0kB, limit 9007199254740991kB, failcnt 0
> [ 269.225722] Memory cgroup stats:cache:8KB rss:511724KB mapped_file:4KB swap:51468KB inactive_anon:265864KB active_anon:245832KB inactive_file:0KB active_file:0KB unevictable:0KB
> [ 269.225741] [ pid ] uid tgid total_vm rss nr_ptes swapents oom_score_adj name
> [ 269.225757] [ 4554] 0 4554 16626 473 17 25 0 bash
> [ 269.225759] [ 4611] 0 4611 103328 90231 208 12260 0 mal
> [ 269.225762] [ 4616] 0 4616 103328 32799 88 7562 0 mal
> [ 269.225764] Memory cgroup out of memory: Kill process 4611 (mal) score 699 or sacrifice child
> [ 269.225766] Killed process 4611 (mal) total-vm:413312kB, anon-rss:360632kB, file-rss:292kB
>
> This version provides more pointed info for memcg in "Memory cgroup stats" section.
>
seems very nice !
some nitpicks below.
> Change log:
> v3 <--- v2
> 1. fix towards hierarchy
> 2. undo rework dump_tasks
> v2 <--- v1
> 1. some modification towards hierarchy
> 2. rework dump_tasks
> 3. rebased on Michal's mm tree since-3.6
>
> Signed-off-by: Sha Zhengju <handai.szj@xxxxxxxxxx>
> ---
> mm/memcontrol.c | 41 +++++++++++++++++++++++++++++++----------
> mm/oom_kill.c | 6 ++++--
> 2 files changed, 35 insertions(+), 12 deletions(-)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 0eab7d5..17317fa 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -118,6 +118,14 @@ static const char * const mem_cgroup_events_names[] = {
> "pgmajfault",
> };
>
> +static const char * const mem_cgroup_lru_names[] = {
> + "inactive_anon",
> + "active_anon",
> + "inactive_file",
> + "active_file",
> + "unevictable",
> +};
> +
> /*
> * Per memcg event counter is incremented at every pagein/pageout. With THP,
> * it will be incremated by the number of pages. This counter is used for
> @@ -1501,8 +1509,8 @@ static void move_unlock_mem_cgroup(struct mem_cgroup *memcg,
> spin_unlock_irqrestore(&memcg->move_lock, *flags);
> }
>
> +#define K(x) ((x) << (PAGE_SHIFT-10))
> /**
> - * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode.
> * @memcg: The memory cgroup that went over limit
> * @p: Task that is going to be killed
> *
> @@ -1520,8 +1528,10 @@ void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
> */
> static char memcg_name[PATH_MAX];
> int ret;
> + struct mem_cgroup *mi;
A nitpick but I prefer using 'iter' as variable name as other for_each_mem_cgroup_tree()
in memcontrol.c
> + unsigned int i;
>
> - if (!memcg || !p)
> + if (!p)
> return;
>
> rcu_read_lock();
> @@ -1569,6 +1579,25 @@ done:
> res_counter_read_u64(&memcg->kmem, RES_USAGE) >> 10,
> res_counter_read_u64(&memcg->kmem, RES_LIMIT) >> 10,
> res_counter_read_u64(&memcg->kmem, RES_FAILCNT));
> +
> + printk(KERN_INFO "Memory cgroup stats:");
why KERN_INFO rather than default_log_level ?
Thanks,
-Kame
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