From a636b327f731143ccc544b966cfd8de6cb6d72c6 Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki Date: Wed, 7 Jan 2009 18:08:08 -0800 Subject: [PATCH] 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 Cc: Li Zefan Cc: Balbir Singh Cc: Daisuke Nishimura Cc: Badari Pulavarty Cc: Jan Blunck Cc: Hirokazu Takahashi Cc: Nick Piggin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memcontrol.h | 7 +++++++ mm/memcontrol.c | 33 +++++++++++++++++++++++++++++---- mm/oom_kill.c | 8 ++++++++ 3 files changed, 44 insertions(+), 4 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 2de6504e01f..2fdd1380bf0 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -102,6 +102,8 @@ static inline bool mem_cgroup_disabled(void) return false; } +extern bool mem_cgroup_oom_called(struct task_struct *task); + #else /* CONFIG_CGROUP_MEM_RES_CTLR */ struct mem_cgroup; @@ -234,6 +236,11 @@ static inline bool mem_cgroup_disabled(void) { return true; } + +static inline bool mem_cgroup_oom_called(struct task_struct *task) +{ + return false; +} #endif /* CONFIG_CGROUP_MEM_CONT */ #endif /* _LINUX_MEMCONTROL_H */ diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 886e2224c5f..659b0c58f13 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -153,7 +153,7 @@ struct mem_cgroup { * 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 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem, 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 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm, 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 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm, 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 @@ static int mem_cgroup_move_parent(struct page_cgroup *pc, 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 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, 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); diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 6b9e758c98a..fd150e3a256 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -560,6 +560,13 @@ void pagefault_out_of_memory(void) /* Got some memory back in the last second. */ return; + /* + * If this is from memcg, oom-killer is already invoked. + * and not worth to go system-wide-oom. + */ + if (mem_cgroup_oom_called(current)) + goto rest_and_return; + if (sysctl_panic_on_oom) panic("out of memory from page fault. panic_on_oom is selected.\n"); @@ -571,6 +578,7 @@ void pagefault_out_of_memory(void) * Give "p" a good chance of killing itself before we * retry to allocate memory. */ +rest_and_return: if (!test_thread_flag(TIF_MEMDIE)) schedule_timeout_uninterruptible(1); } -- 2.41.1