From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx118.postini.com [74.125.245.118]) by kanga.kvack.org (Postfix) with SMTP id 6751A6B00EC for ; Thu, 12 Apr 2012 00:06:29 -0400 (EDT) Received: by lagz14 with SMTP id z14so1647958lag.14 for ; Wed, 11 Apr 2012 21:06:27 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20120411235638.GA1787@cmpxchg.org> References: <1334181627-26942-1-git-send-email-yinghan@google.com> <20120411235638.GA1787@cmpxchg.org> Date: Wed, 11 Apr 2012 21:06:27 -0700 Message-ID: Subject: Re: [PATCH V2 5/5] memcg: change the target nr_to_reclaim for each memcg under kswapd From: Ying Han Content-Type: text/plain; charset=ISO-8859-1 Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner Cc: Michal Hocko , Mel Gorman , KAMEZAWA Hiroyuki , Rik van Riel , Hillf Danton , Hugh Dickins , Dan Magenheimer , linux-mm@kvack.org On Wed, Apr 11, 2012 at 4:56 PM, Johannes Weiner wrote: > On Wed, Apr 11, 2012 at 03:00:27PM -0700, Ying Han wrote: >> Under global background reclaim, the sc->nr_to_reclaim is set to >> ULONG_MAX. Now we are iterating all memcgs under the zone and we >> shouldn't pass the pressure from kswapd for each memcg. >> >> After all, the balance_pgdat() breaks after reclaiming SWAP_CLUSTER_MAX >> pages to prevent building up reclaim priorities. > > shrink_mem_cgroup_zone() bails out of a zone, balance_pgdat() bails > out of a priority loop, there is quite a difference. > > After this patch, kswapd no longer puts equal pressure on all zones in > the zonelist, which was a key reason why we could justify bailing > early out of individual zones in direct reclaim: kswapd will restore > fairness. Guess I see your point here. My intention is to prevent over-reclaim memcgs per-zone by having nr_to_reclaim to ULONG_MAX. Now, we scan each memcg based on get_scan_count() without bailout, do you see a problem w/o this patch? --Ying -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org