From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sd0109e.au.ibm.com (d23rh905.au.ibm.com [202.81.18.225]) by e23smtp04.au.ibm.com (8.13.1/8.13.1) with ESMTP id mB68KBiN018138 for ; Sat, 6 Dec 2008 19:20:11 +1100 Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by sd0109e.au.ibm.com (8.13.8/8.13.8/NCO v9.1) with ESMTP id mB68JBbg051626 for ; Sat, 6 Dec 2008 19:19:12 +1100 Received: from d23av01.au.ibm.com (loopback [127.0.0.1]) by d23av01.au.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id mB68JBVm009844 for ; Sat, 6 Dec 2008 19:19:11 +1100 Date: Sat, 6 Dec 2008 13:48:59 +0530 From: Balbir Singh Subject: Re: [RFC][PATCH -mmotm 1/4] memcg: don't trigger oom at page migration Message-ID: <20081206081859.GC7582@balbir.in.ibm.com> Reply-To: balbir@linux.vnet.ibm.com References: <20081205212208.31d904e0.nishimura@mxp.nes.nec.co.jp> <20081205212304.f7018ea1.nishimura@mxp.nes.nec.co.jp> <20081205133925.GA10004@balbir.in.ibm.com> <20081206114757.c323c63b.d-nishimura@mtf.biglobe.ne.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20081206114757.c323c63b.d-nishimura@mtf.biglobe.ne.jp> Sender: owner-linux-mm@kvack.org Return-Path: To: nishimura@mxp.nes.nec.co.jp Cc: LKML , linux-mm , KAMEZAWA Hiroyuki , Pavel Emelyanov , Li Zefan , Paul Menage , d-nishimura@mtf.biglobe.ne.jp List-ID: * Daisuke Nishimura [2008-12-06 11:47:57]: > On Fri, 5 Dec 2008 19:09:26 +0530 > Balbir Singh wrote: > > > * Daisuke Nishimura [2008-12-05 21:23:04]: > > > > > I think triggering OOM at mem_cgroup_prepare_migration would be just a bit > > > overkill. > > > Returning -ENOMEM would be enough for mem_cgroup_prepare_migration. > > > The caller would handle the case anyway. > > > > > > Signed-off-by: Daisuke Nishimura > > > --- > > > mm/memcontrol.c | 2 +- > > > 1 files changed, 1 insertions(+), 1 deletions(-) > > > > > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > > > index 4dbce1d..50ee1be 100644 > > > --- a/mm/memcontrol.c > > > +++ b/mm/memcontrol.c > > > @@ -1330,7 +1330,7 @@ int mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr) > > > unlock_page_cgroup(pc); > > > > > > if (mem) { > > > - ret = mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem); > > > + ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false); > > > css_put(&mem->css); > > > } > > > *ptr = mem; > > > > > > > Seems reasonable to me. A comment indicating or adding a noreclaim > > wrapper around __mem_cgroup_try_charge to indicate that no reclaim > > will take place will be nice. > > > Ah.. this flag to __mem_cgroup_try_charge doesn't mean "don't reclaim" > but "don't cause oom after it tried to free memory but couldn't > free enough memory after all". Thanks, I mistook the parameter. Thanks for clarifying! > > Thanks, > Daisuke Nishimura. > > > Acked-by: Balbir Singh > > > > -- > > Balbir > > > > -- > > 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 > > > -- Balbir -- 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