Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752075Ab2HMNKT (ORCPT ); Mon, 13 Aug 2012 09:10:19 -0400 Received: from cantor2.suse.de ([195.135.220.15]:56497 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751552Ab2HMNKR (ORCPT ); Mon, 13 Aug 2012 09:10:17 -0400 Date: Mon, 13 Aug 2012 15:10:14 +0200 From: Michal Hocko To: Glauber Costa Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, devel@openvz.org, Johannes Weiner , Andrew Morton , kamezawa.hiroyu@jp.fujitsu.com, Christoph Lameter , David Rientjes , Pekka Enberg , Suleiman Souhlal Subject: Re: [PATCH v2 02/11] memcg: Reclaim when more than one page needed. Message-ID: <20120813131014.GB24248@dhcp22.suse.cz> References: <1344517279-30646-1-git-send-email-glommer@parallels.com> <1344517279-30646-3-git-send-email-glommer@parallels.com> <20120810185417.GB16110@dhcp22.suse.cz> <5028B552.2070708@parallels.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5028B552.2070708@parallels.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 Content-Length: 1965 Lines: 45 On Mon 13-08-12 12:05:38, Glauber Costa wrote: > On 08/10/2012 10:54 PM, Michal Hocko wrote: > > On Thu 09-08-12 17:01:10, Glauber Costa wrote: > >> From: Suleiman Souhlal > >> > >> mem_cgroup_do_charge() was written before kmem accounting, and expects > >> three cases: being called for 1 page, being called for a stock of 32 > >> pages, or being called for a hugepage. If we call for 2 or 3 pages (and > >> both the stack and several slabs used in process creation are such, at > >> least with the debug options I had), it assumed it's being called for > >> stock and just retried without reclaiming. > >> > >> Fix that by passing down a minsize argument in addition to the csize. > >> > >> And what to do about that (csize == PAGE_SIZE && ret) retry? If it's > >> needed at all (and presumably is since it's there, perhaps to handle > >> races), then it should be extended to more than PAGE_SIZE, yet how far? > >> And should there be a retry count limit, of what? For now retry up to > >> COSTLY_ORDER (as page_alloc.c does) and make sure not to do it if > >> __GFP_NORETRY. > >> > >> [v4: fixed nr pages calculation pointed out by Christoph Lameter ] > >> > >> Signed-off-by: Suleiman Souhlal > >> Signed-off-by: Glauber Costa > >> Reviewed-by: Kamezawa Hiroyuki > > > > I am not happy with the min_pages argument but we can do something more > > clever later. > > > > Acked-by: Michal Hocko > > > > I am a bit confused here. Does your ack come before or after your other > comments on this patch? Heh, it was hard Friday ;) Yes, it was after the mind fart... -- Michal Hocko SUSE Labs -- 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/