From f9434ad1552427fab49336e1a6e3ef121895b9d1 Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Wed, 23 Mar 2011 16:42:44 -0700 Subject: memcg: give current access to memory reserves if it's trying to die When a memcg is oom and current has already received a SIGKILL, then give it access to memory reserves with a higher scheduling priority so that it may quickly exit and free its memory. This is identical to the global oom killer and is done even before checking for panic_on_oom: a pending SIGKILL here while panic_on_oom is selected is guaranteed to have come from userspace; the thread only needs access to memory reserves to exit and thus we don't unnecessarily panic the machine until the kernel has no last resort to free memory. Signed-off-by: David Rientjes Cc: Balbir Singh Cc: Daisuke Nishimura Acked-by: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/oom_kill.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 3100bc57036b..62a5cec08a17 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -549,6 +549,17 @@ void mem_cgroup_out_of_memory(struct mem_cgroup *mem, gfp_t gfp_mask) unsigned int points = 0; struct task_struct *p; + /* + * If current has a pending SIGKILL, then automatically select it. The + * goal is to allow it to allocate so that it may quickly exit and free + * its memory. + */ + if (fatal_signal_pending(current)) { + set_thread_flag(TIF_MEMDIE); + boost_dying_task_prio(current, NULL); + return; + } + check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, 0, NULL); limit = mem_cgroup_get_limit(mem) >> PAGE_SHIFT; read_lock(&tasklist_lock); -- cgit v1.2.3