From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with SMTP id D26A46B008C for ; Tue, 23 Feb 2010 19:12:09 -0500 (EST) Received: from m3.gw.fujitsu.co.jp ([10.0.50.73]) by fgwmail7.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o1O0C6rY020034 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Wed, 24 Feb 2010 09:12:06 +0900 Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 2973845DE53 for ; Wed, 24 Feb 2010 09:12:06 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m3.gw.fujitsu.co.jp (Postfix) with ESMTP id D8F7B45DE4D for ; Wed, 24 Feb 2010 09:12:05 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id B4CD71DB8043 for ; Wed, 24 Feb 2010 09:12:05 +0900 (JST) Received: from m105.s.css.fujitsu.com (m105.s.css.fujitsu.com [10.249.87.105]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 568CC1DB803B for ; Wed, 24 Feb 2010 09:12:05 +0900 (JST) Date: Wed, 24 Feb 2010 09:08:36 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [RFC][PATCH] memcg: page fault oom improvement v2 Message-Id: <20100224090836.ba86a4a6.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: References: <20100223120315.0da4d792.kamezawa.hiroyu@jp.fujitsu.com> <20100223140218.0ab8ee29.nishimura@mxp.nes.nec.co.jp> <20100223152116.327a777e.nishimura@mxp.nes.nec.co.jp> <20100223152650.e8fc275d.kamezawa.hiroyu@jp.fujitsu.com> <20100223155543.796138fc.nishimura@mxp.nes.nec.co.jp> <20100223160714.72520b48.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: David Rientjes Cc: Daisuke Nishimura , Balbir Singh , linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On Tue, 23 Feb 2010 14:49:12 -0800 (PST) David Rientjes wrote: > On Tue, 23 Feb 2010, KAMEZAWA Hiroyuki wrote: > > > Ouch, I missed to add memcontrol.h to quilt's reflesh set.. > > This is updated one. Anyway, I'd like to wait for the next mmotm. > > We already have several changes. > > > > I think it would be better to just remove mem_cgroup_out_of_memory() and > make it go through out_of_memory() by specifying a non-NULL pointer to a > struct mem_cgroup. We don't need the duplication in code that these two > functions have and then we can begin to have some consistency with how to > deal with panic_on_oom. > > It would be much better to prefer killing current in pagefault oom > conditions, as the final patch in my oom killer rewrite does, if it is > killable. If not, we scan the tasklist and find another suitable > candidate. If current is bound to a memcg, we pass that to > select_bad_process() so that we only kill other tasks from the same > cgroup. Adding new argument to out_of_memory ? > > This allows us to hijack the TIF_MEMDIE bit to detect when there is a > parallel pagefault oom killing when the oom killer hasn't necessarily been > invoked to kill a system-wide task (it's simply killing current, by > default, and giving it access to memory reserves). Then, we can change > out_of_memory(), which also now handles memcg oom conditions, to always > scan the tasklist first (including for mempolicy and cpuset constrained > ooms), check for any candidates that have TIF_MEMDIE, and return > ERR_PTR(-1UL) if so. That catches the parallel pagefault oom conditions > from needlessly killing memcg tasks. panic_on_oom would only panic after > the tasklist scan has completed and returned != ERR_PTR(-1UL), meaning > pagefault ooms are exempt from that sysctl. > Sorry, I see your concern but I'd like not to do clean-up and bug-fix at the same time. I think clean up after fix is easy in this case. > Anyway, do you think it would be possible to rebase on mmotm with my oom > killer rewrite patches? > They're at > http://www.kernel.org/pub/linux/kernel/people/rientjes/oom-killer-rewrite > I can wait until your patch are merged if necessary. But it seems there will not be much confliction. Thanks, -Kame -- 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