From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 26 Jun 2007 23:57:03 +0200 From: Andrea Arcangeli Subject: Re: [patch] oom: serialize oom killer for cpusets Message-ID: <20070626215702.GA22366@v2.random> References: <20070626205533.GH7059@v2.random> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org Return-Path: To: David Rientjes Cc: Christoph Lameter , linux-mm@kvack.org List-ID: On Tue, Jun 26, 2007 at 02:20:42PM -0700, David Rientjes wrote: > In that case, it would turn into a simple cpuset_exit_oom(tsk); in the > test_tsk_thread_flag(tsk, TIF_MEMDIE) check in exit_notify(). That's > clean, but what happens if tsk gets stuck in TASK_UNINTERRUPTIBLE, for > whatever reason, and then we leave the cpuset locked out of the OOM > killer? I'm trying to avoid having a last_tif_memdie_jiffies for each > struct cpuset. Right, to avoid risking deadlocks with infinite loops like the one I've fixed in nfs (a R state deadlock in that case, not D state), you'd need a last_tif_memdie_jiffies in the cpuset :( I wish there was a cleaner way to detect if we run into a deadlock... At least in your case since you kill "current" you avoid some of the TASK_UNINTERRUPTIBLE deadlocks like the one where the chosen one is blocked in the PG_locked bitflag. The chosen one for you is alive and well running inside alloc_pages, so it's more likely capable to notice that it received a sigkill, than the ones that are already in D state. > I was assuming that your patchset had already reached -mm so I simply I didn't receive any -mm automatic email about it yet, so I assumed it's not yet in. -- 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