From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [PATCH 17 of 24] apply the anti deadlock features only to global oom Message-Id: In-Reply-To: Date: Wed, 22 Aug 2007 14:49:04 +0200 From: Andrea Arcangeli Sender: owner-linux-mm@kvack.org Return-Path: To: linux-mm@kvack.org Cc: David Rientjes List-ID: # HG changeset patch # User Andrea Arcangeli # Date 1187778125 -7200 # Node ID efd1da1efb392cc4e015740d088ea9c6235901e0 # Parent b343d1056f356d60de868bd92422b33290e3c514 apply the anti deadlock features only to global oom Cc: Christoph Lameter The local numa oom will keep killing the current task hoping that's it's not an innocent task and it won't alter the behavior of the rest of the VM. The global oom will not wait for TIF_MEMDIE tasks anymore, so this will be a really local event, not like before when the local-TIF_MEMDIE was effectively a global flag that the global oom would depend on too. Signed-off-by: Andrea Arcangeli diff --git a/mm/oom_kill.c b/mm/oom_kill.c --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -387,9 +387,6 @@ void out_of_memory(struct zonelist *zone /* Got some memory back in the last second. */ return; - if (down_trylock(&OOM_lock)) - return; - if (sysctl_panic_on_oom == 2) panic("out of memory. Compulsory panic_on_oom is selected.\n"); @@ -399,32 +396,39 @@ void out_of_memory(struct zonelist *zone */ constraint = constrained_alloc(zonelist, gfp_mask); cpuset_lock(); - read_lock(&tasklist_lock); - - /* - * This holds the down(OOM_lock)+read_lock(tasklist_lock), so it's - * equivalent to write_lock_irq(tasklist_lock) as far as VM_is_OOM - * is concerned. - */ - if (unlikely(test_bit(0, &VM_is_OOM))) { - if (time_before(jiffies, last_tif_memdie_jiffies + 10*HZ)) - goto out; - printk("detected probable OOM deadlock, so killing another task\n"); - last_tif_memdie_jiffies = jiffies; - } switch (constraint) { case CONSTRAINT_MEMORY_POLICY: + read_lock(&tasklist_lock); oom_kill_process(current, points, "No available memory (MPOL_BIND)", gfp_mask, order); + read_unlock(&tasklist_lock); break; case CONSTRAINT_CPUSET: + read_lock(&tasklist_lock); oom_kill_process(current, points, "No available memory in cpuset", gfp_mask, order); + read_unlock(&tasklist_lock); break; case CONSTRAINT_NONE: + if (down_trylock(&OOM_lock)) + break; + read_lock(&tasklist_lock); + + /* + * This holds the down(OOM_lock)+read_lock(tasklist_lock), + * so it's equivalent to write_lock_irq(tasklist_lock) as + * far as VM_is_OOM is concerned. + */ + if (unlikely(test_bit(0, &VM_is_OOM))) { + if (time_before(jiffies, last_tif_memdie_jiffies + 10*HZ)) + goto out; + printk("detected probable OOM deadlock, so killing another task\n"); + last_tif_memdie_jiffies = jiffies; + } + if (sysctl_panic_on_oom) panic("out of memory. panic_on_oom is selected\n"); retry: @@ -443,12 +447,11 @@ retry: if (oom_kill_process(p, points, "Out of memory", gfp_mask, order)) goto retry; + out: + read_unlock(&tasklist_lock); + up(&OOM_lock); break; } -out: - read_unlock(&tasklist_lock); cpuset_unlock(); - - up(&OOM_lock); -} +} -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org