[PATCH] fix OOM killing of swapoff (7ba34859) · Commits · 戴 / test

These days, if you swapoff when there isn't enough memory, OOM killer gives "BUG: scheduling while atomic" and the machine hangs: badness() needs to do its PF_SWAPOFF return after the task_unlock (tasklist_lock is also held here, so p isn't going to be freed: PF_SWAPOFF might get turned off at any moment, but that doesn't really matter). Signed-off-by:

Hugh Dickins <hugh@veritas.com> Cc: <stable@kernel.org> Signed-off-by:

Andrew Morton <akpm@osdl.org> Signed-off-by:

Linus Torvalds <torvalds@osdl.org>

mm/oom_kill.c

+6 −6

Original line number	Diff line number	Diff line
		@@ -60,12 +60,6 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
		return 0;
		}

		/*
		* swapoff can easily use up all memory, so kill those first.
		*/
		if (p->flags & PF_SWAPOFF)
		return ULONG_MAX;

		/*
		* The memory size of the process is the basis for the badness.
		*/
		@@ -76,6 +70,12 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
		*/
		task_unlock(p);

		/*
		* swapoff can easily use up all memory, so kill those first.
		*/
		if (p->flags & PF_SWAPOFF)
		return ULONG_MAX;

		/*
		* Processes which fork a lot of child processes are likely
		* a good choice. We add half the vmsize of the children if they

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