Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755379AbcDKPeZ (ORCPT ); Mon, 11 Apr 2016 11:34:25 -0400 Received: from mail-wm0-f66.google.com ([74.125.82.66]:36339 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932138AbcDKPeA (ORCPT ); Mon, 11 Apr 2016 11:34:00 -0400 Date: Mon, 11 Apr 2016 17:33:58 +0200 From: Michal Hocko To: Vlastimil Babka Cc: Andrew Morton , Linus Torvalds , Johannes Weiner , Mel Gorman , David Rientjes , Tetsuo Handa , Joonsoo Kim , Hillf Danton , linux-mm@kvack.org, LKML Subject: Re: [PATCH 09/11] mm, compaction: Abstract compaction feedback to helpers Message-ID: <20160411153357.GM23157@dhcp22.suse.cz> References: <1459855533-4600-1-git-send-email-mhocko@kernel.org> <1459855533-4600-10-git-send-email-mhocko@kernel.org> <570BB719.2030007@suse.cz> <20160411151410.GL23157@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160411151410.GL23157@dhcp22.suse.cz> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1001 Lines: 25 On Mon 11-04-16 17:14:10, Michal Hocko wrote: > On Mon 11-04-16 16:39:21, Vlastimil Babka wrote: > > On 04/05/2016 01:25 PM, Michal Hocko wrote: [...] > > >+ /* > > >+ * Checks for THP-specific high-order allocations and back off > > >+ * if the the compaction backed off > > >+ */ > > >+ if (is_thp_gfp_mask(gfp_mask) && compaction_withdrawn(compact_result)) > > >+ goto nopage; > > > > The change of semantics for THP is not trivial here and should at least be > > discussed in changelog. CONTENDED and DEFERRED is only subset of > > compaction_withdrawn() as seen above. > > True. My main motivation was to get rid of the compaction specific code > from the allocator path as much as possible. I can drop the above hunk I was thinking about this some more and will drop the hunk. I would rather have this patch without side effects as much as possible. A follow up patch can get rid of the specific checks and use a simpler ones. I will post -fix patch to Andrew. -- Michal Hocko SUSE Labs