From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751484AbbCTHvg (ORCPT ); Fri, 20 Mar 2015 03:51:36 -0400 Received: from cantor2.suse.de ([195.135.220.15]:36198 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750801AbbCTHve (ORCPT ); Fri, 20 Mar 2015 03:51:34 -0400 Message-ID: <550BD183.5020005@suse.cz> Date: Fri, 20 Mar 2015 08:51:31 +0100 From: Vlastimil Babka User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Gioh Kim , akpm@linux-foundation.org, rientjes@google.com, iamjoonsoo.kim@lge.com, mgorman@suse.de CC: linux-mm@kvack.org, linux-kernel@vger.kernel.org, gunho.lee@lge.com Subject: Re: [PATCH] [RFC] mm/compaction: initialize compaction information References: <1426743031-30096-1-git-send-email-gioh.kim@lge.com> <550A8BA9.9040005@suse.cz> <550A8E31.4040304@lge.com> <550A9086.3080508@suse.cz> <550B5CD1.5010306@lge.com> In-Reply-To: <550B5CD1.5010306@lge.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/20/2015 12:33 AM, Gioh Kim wrote: >>> diff --git a/mm/compaction.c b/mm/compaction.c >>> index 8c0d945..827ec06 100644 >>> --- a/mm/compaction.c >>> +++ b/mm/compaction.c >>> @@ -1587,8 +1587,10 @@ static void __compact_pgdat(pg_data_t *pgdat, struct compact_control *cc) >>> INIT_LIST_HEAD(&cc->freepages); >>> INIT_LIST_HEAD(&cc->migratepages); >>> >>> - if (cc->order == -1 || !compaction_deferred(zone, cc->order)) >>> + if (cc->order == -1 || !compaction_deferred(zone, cc->order)) { >>> + __reset_isolation_suitable(zone); >> >> This will also trigger reset when called from kswapd through compact_pgdat() and >> !compaction_deferred() is true. >> The reset should be restricted to cc->order == -1 which only happens from /proc >> trigger. >> >>> compact_zone(zone, cc); >>> + } >>> >>> if (cc->order > 0) { >>> if (zone_watermark_ok(zone, cc->order, >>> >> >> > > I've not been familiar with compaction code. > I think cc->order is -1 only if __compact_pgdat is called via /proc. Yes that's what I meant. > This is ugly but I don't have better solution. > Do you have better idea? It's not ugly IMHO. There are more tests for -1 like this, e.g. in compaction_suitable(). Maybe just add some comment such as: /* * When called via /proc/sys/vm/compact_memory make sure we compact * the whole zone regardless of cached scanner positions. */ > diff --git a/mm/compaction.c b/mm/compaction.c > index 8c0d945..5b4e255 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -1587,6 +1587,9 @@ static void __compact_pgdat(pg_data_t *pgdat, struct compact_control *cc) > INIT_LIST_HEAD(&cc->freepages); > INIT_LIST_HEAD(&cc->migratepages); > > + if (cc->order == -1) > + __reset_isolation_suitable(zone); > + > if (cc->order == -1 || !compaction_deferred(zone, cc->order)) > compact_zone(zone, cc); > > >