From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751908Ab3KDRES (ORCPT ); Mon, 4 Nov 2013 12:04:18 -0500 Received: from cantor2.suse.de ([195.135.220.15]:60902 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751526Ab3KDREQ (ORCPT ); Mon, 4 Nov 2013 12:04:16 -0500 Date: Mon, 4 Nov 2013 17:04:13 +0000 From: Mel Gorman To: Don Morris Cc: LKML , David Rientjes Subject: Re: BUG: soft lockup - CPU#8 stuck for 22s! Message-ID: <20131104170413.GA25764@suse.de> References: <5266B5F2.5070102@hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <5266B5F2.5070102@hp.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 22, 2013 at 01:29:22PM -0400, Don Morris wrote: > Greetings, all. > > Just wanted to drop this out there to see if it rang any bells. > I've been getting a soft lockup (numad thread stuck on a cpu > while attempting to attach a task to a cgroup) for a while now, > but I thought it was only happening when I applied Mel Gorman's > set of AutoNUMA patches. This maybe? ---8<--- mm: memcontrol: Release css_set_lock when aborting an OOM scan css_task_iter_start acquires the css_set_lock and it must be released with a call to css_task_iter_end. Commmit 9cbb78bb (mm, memcg: introduce own oom handler to iterate only over its own threads) introduced a loop that was not guaranteed to call css_task_iter_end. Cc: stable Signed-off-by: Mel Gorman diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 5ef8929..941f67d 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1795,6 +1795,7 @@ static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, mem_cgroup_iter_break(memcg, iter); if (chosen) put_task_struct(chosen); + css_task_iter_end(&it); return; case OOM_SCAN_OK: break;