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 and take hierarchy into consideration:
Based on Michal's advice, we take hierarchy into consideration :
supppose we trigger an OOM on A's limit
root_memcg
|
A (use_hierachy=1)
/ \
B C
|
D
then the printed info will be:
Memory cgroup stats for /A:...
Memory cgroup stats for /A/B:...
Memory cgroup stats for /A/C:...
Memory cgroup stats for /A/B/D:...
Following are samples of oom output:
(1)Before change:
[ 204.308085] mal-80 invoked oom-killer: gfp_mask=0xd0, order=0, oom_score_adj=0
[ 204.308088] mal-80 cpuset=/ mems_allowed=0
[ 204.308090] Pid: 2376, comm: mal-80 Not tainted 3.7.0+ #4
[ 204.308091] Call Trace:
[ 204.308100] [<ffffffff81692515>] dump_header+0x83/0x1ca
[ 204.308107] [<ffffffff8112effe>] oom_kill_process+0x1be/0x320
..... (call trace)
[ 204.308146] [<ffffffff8169c418>] page_fault+0x28/0x30
[ 204.308148] Task in /1/2 killed as a result of limit of /1
[ 204.308150] memory: usage 102400kB, limit 102400kB, failcnt 181
[ 204.308151] memory+swap: usage 102400kB, limit 102400kB, failcnt 0
[ 204.308151] Mem-Info:
[ 204.308152] Node 0 DMA per-cpu: <<<<<<<<<<<<<<<<<<<<< print per cpu pageset stat
[ 204.308154] CPU 0: hi: 0, btch: 1 usd: 0
......
[ 204.308157] CPU 3: hi: 0, btch: 1 usd: 0
[ 204.308158] Node 0 DMA32 per-cpu:
[ 204.308159] CPU 0: hi: 186, btch: 31 usd: 134
......
[ 204.308162] CPU 3: hi: 186, btch: 31 usd: 141
<<<<<<<<<<<<<<<<<<<<< print global page state
[ 204.308169] active_anon:94139 inactive_anon:41771 isolated_anon:0
[ 204.308169] active_file:24655 inactive_file:60269 isolated_file:0
[ 204.308169] unevictable:0 dirty:11 writeback:0 unstable:0
[ 204.308169] free:729657 slab_reclaimable:6861 slab_unreclaimable:6199
[ 204.308169] mapped:28794 shmem:35794 pagetables:5774 bounce:0
[ 204.308169] free_cma:0
<<<<<<<<<<<<<<<<<<<<< print per zone page state
[ 204.308171] Node 0 DMA free:15836kB min:260kB low:324kB high:388kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:15596kB managed:15852kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:0kB slab_unreclaimable:16kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no
[ 204.308174] lowmem_reserve[]: 0 3175 3899 3899
[ 204.308176] Node 0 DMA32 free:2887244kB ...
[ 204.308174] lowmem_reserve[]: 0 3175 3899 3899
[ 204.308176] Node 0 DMA32 free:2887244kB ...
[ 204.308185] lowmem_reserve[]: 0 0 0 0
[ 204.308187] Node 0 DMA: 1*4kB (U) 1*8kB (U) ...
[ 204.308196] Node 0 DMA32: 21*4kB (UEM) 58*8kB (UE) ...
[ 204.308213] 120727 total pagecache pages
[ 204.308214] 0 pages in swap cache
<<<<<<<<<<<<<<<<<<<<< print global swap cache stat
[ 204.308215] Swap cache stats: add 0, delete 0, find 0/0
[ 204.308215] Free swap = 499708kB
[ 204.308216] Total swap = 499708kB
[ 204.316300] 1040368 pages RAM
[ 204.316304] 58707 pages reserved
[ 204.316308] 175021 pages shared
[ 204.316312] 174709 pages non-shared
[ 204.316315] [ pid ] uid tgid total_vm rss nr_ptes swapents oom_score_adj name
[ 204.316348] [ 1996] 1000 1996 6007 1324 17 0 0 bash
[ 204.316354] [ 2283] 1000 2283 6008 1324 18 0 0 bash
[ 204.316356] [ 2367] 1000 2367 8721 7742 22 0 0 mal-30
[ 204.316358] [ 2376] 1000 2376 21521 17841 43 0 0 mal-80
[ 204.316359] Memory cgroup out of memory: Kill process 2376 (mal-80) score 698 or sacrifice child
[ 204.316361] Killed process 2376 (mal-80) total-vm:86084kB, anon-rss:71020kB, file-rss:344kB
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
[ 328.035727] mal-80 invoked oom-killer: gfp_mask=0xd0, order=0, oom_score_adj=0
[ 328.035730] mal-80 cpuset=/ mems_allowed=0
[ 328.035732] Pid: 2439, comm: mal-80 Not tainted 3.7.0+ #5
[ 328.035733] Call Trace:
[ 328.035743] [<ffffffff81692625>] dump_header+0x83/0x1d1
.......(call trace)
[ 328.035793] Task in /1/2 killed as a result of limit of /1
[ 328.035795] memory: usage 101376kB, limit 101376kB, failcnt 815
[ 328.035796] memory+swap: usage 101376kB, limit 101376kB, failcnt 0
[ 328.035797] Memory cgroup stats for /1:cache:0KB rss:31052KB mapped_file:0KB swap:0KB inactive_anon:15620KB active_anon:15432KB inactive_file:0KB active_file:0KB unevictable:0KB
[ 328.035804] Memory cgroup stats for /1/2:cache:44KB rss:70280KB mapped_file:0KB swap:0KB inactive_anon:16640KB active_anon:53608KB inactive_file:44KB active_file:0KB unevictable:0KB
[ 328.035809] [ pid ] uid tgid total_vm rss nr_ptes swapents oom_score_adj name
[ 328.035841] [ 2239] 0 2239 6005 1322 17 0 0 god
[ 328.035843] [ 2361] 0 2361 6004 1321 17 0 0 god
[ 328.035845] [ 2437] 0 2437 8721 7741 22 0 0 mal-30
[ 328.035846] [ 2439] 0 2439 21521 17575 42 0 0 mal-80
[ 328.035847] Memory cgroup out of memory: Kill process 2439 (mal-80) score 665 or sacrifice child
[ 328.035849] Killed process 2439 (mal-80) total-vm:86084kB, anon-rss:69960kB, file-rss:340kB
This version provides more pointed info for memcg in "Memory cgroup stats" section.
Change log:
v4 <--- v3
1. print more info in hierarchy
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 | 47 +++++++++++++++++++++++++++++++++++++----------
mm/oom_kill.c | 6 ++++--
2 files changed, 41 insertions(+), 12 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index bbfac50..e2d17c8 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -116,6 +116,14 @@ 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
@@ -1389,8 +1397,9 @@ 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.
+ * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
* @memcg: The memory cgroup that went over limit
* @p: Task that is going to be killed
*
@@ -1408,8 +1417,10 @@ 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 *iter;
+ unsigned int i;
- if (!memcg || !p)
+ if (!p)
return;
rcu_read_lock();
@@ -1453,6 +1464,30 @@ done:
res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10,
res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10,
res_counter_read_u64(&memcg->memsw, RES_FAILCNT));
+
+ for_each_mem_cgroup_tree(iter, memcg) {
+ pr_info("Memory cgroup stats");
+
+ rcu_read_lock();
+ ret = cgroup_path(iter->css.cgroup, memcg_name, PATH_MAX);
+ if (!ret)
+ pr_cont(" for %s", memcg_name);
+ rcu_read_unlock();
+ pr_cont(":");
+
+ for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
+ if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
+ continue;
+ pr_cont("%s:%ldKB ", mem_cgroup_stat_names[i],
+ K(mem_cgroup_read_stat(iter, i)));
+ }
+
+ for (i = 0; i < NR_LRU_LISTS; i++)
+ pr_cont("%s:%luKB ", mem_cgroup_lru_names[i],
+ K(mem_cgroup_nr_lru_pages(iter, BIT(i))));
+
+ pr_cont("\n");
+ }
}
/*
@@ -4160,14 +4195,6 @@ static int memcg_numa_stat_show(struct cgroup *cont, struct cftype *cft,
}
#endif /* CONFIG_NUMA */
-static const char * const mem_cgroup_lru_names[] = {
- "inactive_anon",
- "active_anon",
- "inactive_file",
- "active_file",
- "unevictable",
-};
-
static inline void mem_cgroup_lru_names_not_uptodate(void)
{
BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS);
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 0399f14..79e451a 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -386,8 +386,10 @@ static void dump_header(struct task_struct *p, gfp_t gfp_mask, int order,
cpuset_print_task_mems_allowed(current);
task_unlock(current);
dump_stack();
- mem_cgroup_print_oom_info(memcg, p);
- show_mem(SHOW_MEM_FILTER_NODES);
+ if (memcg)
+ mem_cgroup_print_oom_info(memcg, p);
+ else
+ show_mem(SHOW_MEM_FILTER_NODES);
if (sysctl_oom_dump_tasks)
dump_tasks(memcg, nodemask);
}
--
1.7.9.5
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