From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx134.postini.com [74.125.245.134]) by kanga.kvack.org (Postfix) with SMTP id 34F556B017F for ; Tue, 26 Jun 2012 05:17:48 -0400 (EDT) Received: by dakp5 with SMTP id p5so8048803dak.14 for ; Tue, 26 Jun 2012 02:17:47 -0700 (PDT) Date: Tue, 26 Jun 2012 02:17:45 -0700 (PDT) From: David Rientjes Subject: Re: [PATCH 02/11] memcg: Reclaim when more than one page needed. In-Reply-To: <4FE97C20.8010500@parallels.com> Message-ID: References: <1340633728-12785-1-git-send-email-glommer@parallels.com> <1340633728-12785-3-git-send-email-glommer@parallels.com> <4FE960D6.4040409@parallels.com> <4FE97C20.8010500@parallels.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Glauber Costa Cc: cgroups@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , linux-kernel@vger.kernel.org, Frederic Weisbecker , Pekka Enberg , Michal Hocko , Johannes Weiner , Christoph Lameter , devel@openvz.org, kamezawa.hiroyu@jp.fujitsu.com, Tejun Heo , Suleiman Souhlal On Tue, 26 Jun 2012, Glauber Costa wrote: > > Nope, have you checked the output of /sys/kernel/slab/.../order when > > running slub? On my workstation 127 out of 316 caches have order-2 or > > higher by default. > > > > Well, this is still on the side of my argument, since this is still a majority > of them being low ordered. Ok, so what happens if I pass slub_min_order=2 on the command line? We never retry? > The code here does not necessarily have to retry - > if I understand it correctly - we just retry for very small allocations > because that is where our likelihood of succeeding is. > Well, the comment for NR_PAGES_TO_RETRY says /* * We need a number that is small enough to be likely to have been * reclaimed even under pressure, but not too big to trigger unnecessary * retries */ and mmzone.h says /* * PAGE_ALLOC_COSTLY_ORDER is the order at which allocations are deemed * costly to service. That is between allocation orders which should * coalesce naturally under reasonable reclaim pressure and those which * will not. */ #define PAGE_ALLOC_COSTLY_ORDER 3 so I'm trying to reconcile which one is correct. -- 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