Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752245AbcD1Ird (ORCPT ); Thu, 28 Apr 2016 04:47:33 -0400 Received: from mx2.suse.de ([195.135.220.15]:60274 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751094AbcD1Irb (ORCPT ); Thu, 28 Apr 2016 04:47:31 -0400 Subject: Re: [PATCH 08/14] mm, compaction: Abstract compaction feedback to helpers To: Michal Hocko , Andrew Morton References: <1461181647-8039-1-git-send-email-mhocko@kernel.org> <1461181647-8039-9-git-send-email-mhocko@kernel.org> Cc: Linus Torvalds , Johannes Weiner , Mel Gorman , David Rientjes , Tetsuo Handa , Joonsoo Kim , Hillf Danton , linux-mm@kvack.org, LKML , Michal Hocko From: Vlastimil Babka Message-ID: <5721CE20.6070801@suse.cz> Date: Thu, 28 Apr 2016 10:47:28 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.7.2 MIME-Version: 1.0 In-Reply-To: <1461181647-8039-9-git-send-email-mhocko@kernel.org> 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 Content-Length: 1091 Lines: 24 On 04/20/2016 09:47 PM, Michal Hocko wrote: > From: Michal Hocko > > Compaction can provide a wild variation of feedback to the caller. Many > of them are implementation specific and the caller of the compaction > (especially the page allocator) shouldn't be bound to specifics of the > current implementation. > > This patch abstracts the feedback into three basic types: > - compaction_made_progress - compaction was active and made some > progress. > - compaction_failed - compaction failed and further attempts to > invoke it would most probably fail and therefore it is not > worth retrying > - compaction_withdrawn - compaction wasn't invoked for an > implementation specific reasons. In the current implementation > it means that the compaction was deferred, contended or the > page scanners met too early without any progress. Retrying is > still worthwhile. > > [vbabka@suse.cz: do not change thp back off behavior] > Signed-off-by: Michal Hocko Acked-by: Vlastimil Babka