oom: oom_kill_process: fix the child_points logic (dc1b83ab) · Commits · 戴 / test

oom_kill_process() starts with victim_points == 0. This means that (most likely) any child has more points and can be killed erroneously. Also, "children has a different mm" doesn't match the reality, we should check child->mm != t->mm. This check is not exactly correct if t->mm == NULL but this doesn't really matter, oom_kill_task() will kill them anyway. Note: "Kill all processes sharing p->mm" in oom_kill_task() is wrong too. Signed-off-by:

Oleg Nesterov <oleg@redhat.com> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

mm/oom_kill.c

+8 −3

Original line number	Diff line number	Diff line
		@@ -458,10 +458,10 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
		struct mem_cgroup mem, nodemask_t nodemask,
		const char *message)
		{
		struct task_struct *victim = p;
		struct task_struct *victim;
		struct task_struct *child;
		struct task_struct *t = p;
		unsigned int victim_points = 0;
		struct task_struct *t;
		unsigned int victim_points;

		if (printk_ratelimit())
		dump_header(p, gfp_mask, order, mem, nodemask);
		@@ -487,10 +487,15 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
		* parent. This attempts to lose the minimal amount of work done while
		* still freeing memory.
		*/
		victim_points = oom_badness(p, mem, nodemask, totalpages);
		victim = p;
		t = p;
		do {
		list_for_each_entry(child, &t->children, sibling) {
		unsigned int child_points;

		if (child->mm == t->mm)
		continue;
		/*
		* oom_badness() returns 0 if the thread is unkillable
		*/

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