Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751832Ab2FZEJQ (ORCPT ); Tue, 26 Jun 2012 00:09:16 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:41818 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750746Ab2FZEJO (ORCPT ); Tue, 26 Jun 2012 00:09:14 -0400 Date: Mon, 25 Jun 2012 21:09:11 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com 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 Subject: Re: [PATCH 02/11] memcg: Reclaim when more than one page needed. In-Reply-To: <1340633728-12785-3-git-send-email-glommer@parallels.com> Message-ID: References: <1340633728-12785-1-git-send-email-glommer@parallels.com> <1340633728-12785-3-git-send-email-glommer@parallels.com> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2587 Lines: 78 On Mon, 25 Jun 2012, Glauber Costa wrote: > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 9304db2..8e601e8 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -2158,8 +2158,16 @@ enum { > CHARGE_OOM_DIE, /* the current is killed because of OOM */ > }; > > +/* > + * 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 Whitespace. > + * retries > + */ > +#define NR_PAGES_TO_RETRY 2 > + Should be 1 << PAGE_ALLOC_COSTLY_ORDER? Where does this number come from? The changelog doesn't specify. > static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, > - unsigned int nr_pages, bool oom_check) > + unsigned int nr_pages, unsigned int min_pages, > + bool oom_check) > { > unsigned long csize = nr_pages * PAGE_SIZE; > struct mem_cgroup *mem_over_limit; > @@ -2182,18 +2190,18 @@ static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, > } else > mem_over_limit = mem_cgroup_from_res_counter(fail_res, res); > /* > - * nr_pages can be either a huge page (HPAGE_PMD_NR), a batch > - * of regular pages (CHARGE_BATCH), or a single regular page (1). > - * > * Never reclaim on behalf of optional batching, retry with a > * single page instead. > */ > - if (nr_pages == CHARGE_BATCH) > + if (nr_pages > min_pages) > return CHARGE_RETRY; > > if (!(gfp_mask & __GFP_WAIT)) > return CHARGE_WOULDBLOCK; > > + if (gfp_mask & __GFP_NORETRY) > + return CHARGE_NOMEM; > + > ret = mem_cgroup_reclaim(mem_over_limit, gfp_mask, flags); > if (mem_cgroup_margin(mem_over_limit) >= nr_pages) > return CHARGE_RETRY; > @@ -2206,7 +2214,7 @@ static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, > * unlikely to succeed so close to the limit, and we fall back > * to regular pages anyway in case of failure. > */ > - if (nr_pages == 1 && ret) > + if (nr_pages <= NR_PAGES_TO_RETRY && ret) > return CHARGE_RETRY; > > /* > @@ -2341,7 +2349,8 @@ again: > nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES; > } > > - ret = mem_cgroup_do_charge(memcg, gfp_mask, batch, oom_check); > + ret = mem_cgroup_do_charge(memcg, gfp_mask, batch, nr_pages, > + oom_check); > switch (ret) { > case CHARGE_OK: > break; -- 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/