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>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 886e222..659b0c5 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -153,7 +153,7 @@
* Should the accounting and control be hierarchical, per subtree?
*/
bool use_hierarchy;
-
+ unsigned long last_oom_jiffies;
int obsolete;
atomic_t refcnt;
/*
@@ -615,6 +615,22 @@
return ret;
}
+bool mem_cgroup_oom_called(struct task_struct *task)
+{
+ bool ret = false;
+ struct mem_cgroup *mem;
+ struct mm_struct *mm;
+
+ rcu_read_lock();
+ mm = task->mm;
+ if (!mm)
+ mm = &init_mm;
+ mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
+ if (mem && time_before(jiffies, mem->last_oom_jiffies + HZ/10))
+ ret = true;
+ rcu_read_unlock();
+ return ret;
+}
/*
* Unlike exported interface, "oom" parameter is added. if oom==true,
* oom-killer can be invoked.
@@ -626,6 +642,13 @@
struct mem_cgroup *mem, *mem_over_limit;
int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
struct res_counter *fail_res;
+
+ if (unlikely(test_thread_flag(TIF_MEMDIE))) {
+ /* Don't account this! */
+ *memcg = NULL;
+ return 0;
+ }
+
/*
* We always charge the cgroup the mm_struct belongs to.
* The mm_struct's mem_cgroup changes on task migration if the
@@ -694,8 +717,10 @@
continue;
if (!nr_retries--) {
- if (oom)
+ if (oom) {
mem_cgroup_out_of_memory(mem, gfp_mask);
+ mem->last_oom_jiffies = jiffies;
+ }
goto nomem;
}
}
@@ -832,7 +857,7 @@
ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false);
- if (ret)
+ if (ret || !parent)
return ret;
if (!get_page_unless_zero(page))
@@ -883,7 +908,7 @@
mem = memcg;
ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true);
- if (ret)
+ if (ret || !mem)
return ret;
__mem_cgroup_commit_charge(mem, pc, ctype);