From 158e0a2d1b3cffed8b46cbc56393a1394672ef79 Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki Date: Tue, 10 Aug 2010 18:03:00 -0700 Subject: memcg: use find_lock_task_mm() in memory cgroups oom When the OOM killer scans task, it check a task is under memcg or not when it's called via memcg's context. But, as Oleg pointed out, a thread group leader may have NULL ->mm and task_in_mem_cgroup() may do wrong decision. We have to use find_lock_task_mm() in memcg as generic OOM-Killer does. Signed-off-by: KAMEZAWA Hiroyuki Cc: Oleg Nesterov Cc: Daisuke Nishimura Cc: Balbir Singh Reviewed-by: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 10 +++++++--- mm/oom_kill.c | 2 +- 2 files changed, 8 insertions(+), 4 deletions(-) (limited to 'mm') diff --git a/mm/memcontrol.c b/mm/memcontrol.c index ea5f5edf00b7..f52b0a1861c4 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -47,6 +47,7 @@ #include #include #include +#include #include "internal.h" #include @@ -838,10 +839,13 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem) { int ret; struct mem_cgroup *curr = NULL; + struct task_struct *p; - task_lock(task); - curr = try_get_mem_cgroup_from_mm(task->mm); - task_unlock(task); + p = find_lock_task_mm(task); + if (!p) + return 0; + curr = try_get_mem_cgroup_from_mm(p->mm); + task_unlock(p); if (!curr) return 0; /* diff --git a/mm/oom_kill.c b/mm/oom_kill.c index d3def05a33d9..5014e50644d1 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -106,7 +106,7 @@ static void boost_dying_task_prio(struct task_struct *p, * pointer. Return p, or any of its subthreads with a valid ->mm, with * task_lock() held. */ -static struct task_struct *find_lock_task_mm(struct task_struct *p) +struct task_struct *find_lock_task_mm(struct task_struct *p) { struct task_struct *t = p; -- cgit v1.2.3