Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752990Ab1DZJju (ORCPT ); Tue, 26 Apr 2011 05:39:50 -0400 Received: from mail-ww0-f44.google.com ([74.125.82.44]:48889 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752704Ab1DZJjt convert rfc822-to-8bit (ORCPT ); Tue, 26 Apr 2011 05:39:49 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=edyNqcQxjGX0bb6rckDBu8ySeaby8L1jYfh0+6lTnfnHnfq6XFbp4RJvbzRTLZqluL jlIjubLJbyAIIwgsA8gbT7BFomice6qOl62KrgYy6udq3j5BUM1u3kTrXGun0cwIcVBb +aSJmYwOzVnXavBndutDERKcCt4PVmCJuZgzg= MIME-Version: 1.0 In-Reply-To: References: <20110426085953.GA12389@darkstar> Date: Tue, 26 Apr 2011 17:39:47 +0800 Message-ID: Subject: Re: [PATCH v2] virtio_balloon: disable oom killer when fill balloon From: Dave Young To: Minchan Kim Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, kosaki.motohiro@jp.fujitsu.com, linux-mm Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2223 Lines: 66 On Tue, Apr 26, 2011 at 5:28 PM, Minchan Kim wrote: > Please resend this with [2/2] to linux-mm. > > On Tue, Apr 26, 2011 at 5:59 PM, Dave Young wrote: >> When memory pressure is high, virtio ballooning will probably cause oom killing. >> Even if alloc_page with GFP_NORETRY itself does not directly trigger oom it >> will make memory becoming low then memory alloc of other processes will trigger >> oom killing. It is not desired behaviour. > > I can't understand why it is undesirable. > Why do we have to handle it specially? > Suppose user run some random memory hogging process while ballooning it will be undesirable. > >> >> Here disable oom killer in fill_balloon to address this issue. >> Add code comment as KOSAKI Motohiro's suggestion. >> >> Signed-off-by: Dave Young >> --- >>  drivers/virtio/virtio_balloon.c |    8 ++++++++ >>  1 file changed, 8 insertions(+) >> >> --- linux-2.6.orig/drivers/virtio/virtio_balloon.c      2011-04-26 11:39:14.053118406 +0800 >> +++ linux-2.6/drivers/virtio/virtio_balloon.c   2011-04-26 16:54:56.419741542 +0800 >> @@ -25,6 +25,7 @@ >>  #include >>  #include >>  #include >> +#include >> >>  struct virtio_balloon >>  { >> @@ -102,6 +103,12 @@ static void fill_balloon(struct virtio_b >>        /* We can only do one array worth at a time. */ >>        num = min(num, ARRAY_SIZE(vb->pfns)); >> >> +       /* Disable oom killer for indirect oom due to our memory consuming >> +        * Currently only hibernation code use oom_killer_disable, > > Hmm, Please look at current mmotm. Now oom_killer_disabled is used by > do_try_to_free_pages in mmotm so it could make unnecessary oom kill. > > BTW, I can't understand why we need to handle virtio by special. > Could you explain it in detail? :) > > > > -- > Kind regards, > Minchan Kim > -- Regards dave -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/