On 11/09/2012 04:12 PM, Kamezawa Hiroyuki wrote:
> (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
>
Okay, got it.
>> + 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 ?
>
Err, I just keep the level consistent with the upper part of this
function. But the log levels
in oom are various: default, KERN_WARNING, KERN_INFO... etc. How about
reconcile them
in another individual patch? : )
Thanks,
Sha
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