From 0aad4b3124850e85fe54e610802f0917ce46a1ae Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Mon, 9 Aug 2010 17:18:59 -0700 Subject: [PATCH] oom: fold __out_of_memory into out_of_memory __out_of_memory() only has a single caller, so fold it into out_of_memory() and add a comment about locking for its call to oom_kill_process(). Signed-off-by: David Rientjes Cc: KAMEZAWA Hiroyuki Acked-by: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/oom_kill.c | 65 +++++++++++++++++++++++---------------------------- 1 file changed, 29 insertions(+), 36 deletions(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index cba18c06e50..26ae6975fa3 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -628,41 +628,6 @@ static void clear_system_oom(void) spin_unlock(&zone_scan_lock); } - -/* - * Must be called with tasklist_lock held for read. - */ -static void __out_of_memory(gfp_t gfp_mask, int order, const nodemask_t *mask) -{ - struct task_struct *p; - unsigned long points; - - if (sysctl_oom_kill_allocating_task) - if (!oom_kill_process(current, gfp_mask, order, 0, NULL, - "Out of memory (oom_kill_allocating_task)")) - return; -retry: - /* - * Rambo mode: Shoot down a process and hope it solves whatever - * issues we may have. - */ - p = select_bad_process(&points, NULL, mask); - - if (PTR_ERR(p) == -1UL) - return; - - /* Found nothing?!?! Either we hang forever, or we panic. */ - if (!p) { - dump_header(NULL, gfp_mask, order, NULL); - read_unlock(&tasklist_lock); - panic("Out of memory and no killable processes...\n"); - } - - if (oom_kill_process(p, gfp_mask, order, points, NULL, - "Out of memory")) - goto retry; -} - /** * out_of_memory - kill the "best" process when we run out of memory * @zonelist: zonelist pointer @@ -678,7 +643,9 @@ retry: void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order, nodemask_t *nodemask) { + struct task_struct *p; unsigned long freed = 0; + unsigned long points; enum oom_constraint constraint = CONSTRAINT_NONE; blocking_notifier_call_chain(&oom_notify_list, 0, &freed); @@ -703,10 +670,36 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, if (zonelist) constraint = constrained_alloc(zonelist, gfp_mask, nodemask); check_panic_on_oom(constraint, gfp_mask, order); + read_lock(&tasklist_lock); - __out_of_memory(gfp_mask, order, + if (sysctl_oom_kill_allocating_task) { + /* + * oom_kill_process() needs tasklist_lock held. If it returns + * non-zero, current could not be killed so we must fallback to + * the tasklist scan. + */ + if (!oom_kill_process(current, gfp_mask, order, 0, NULL, + "Out of memory (oom_kill_allocating_task)")) + return; + } + +retry: + p = select_bad_process(&points, NULL, constraint == CONSTRAINT_MEMORY_POLICY ? nodemask : NULL); + if (PTR_ERR(p) == -1UL) + return; + + /* Found nothing?!?! Either we hang forever, or we panic. */ + if (!p) { + dump_header(NULL, gfp_mask, order, NULL); + read_unlock(&tasklist_lock); + panic("Out of memory and no killable processes...\n"); + } + + if (oom_kill_process(p, gfp_mask, order, points, NULL, + "Out of memory")) + goto retry; read_unlock(&tasklist_lock); /* -- 2.39.3