From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx119.postini.com [74.125.245.119]) by kanga.kvack.org (Postfix) with SMTP id 443886B0031 for ; Thu, 25 Jul 2013 11:10:59 -0400 (EDT) Date: Thu, 25 Jul 2013 11:10:49 -0400 From: Johannes Weiner Subject: Re: [patch 3/3] mm: page_alloc: fair zone allocator policy Message-ID: <20130725151049.GM715@cmpxchg.org> References: <1374267325-22865-1-git-send-email-hannes@cmpxchg.org> <1374267325-22865-4-git-send-email-hannes@cmpxchg.org> <51ED9433.60707@redhat.com> <51F0CACE.7040609@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <51F0CACE.7040609@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Paul Bolle Cc: Rik van Riel , Andrew Morton , Mel Gorman , Andrea Arcangeli , Paul Bolle , linux-mm@kvack.org, linux-kernel@vger.kernel.org Hi Paul Bolle^W^W Sam Ben^W^W Hush Bensen^W^W Mtrr Patt^W^W Ric Mason^W^W Will Huck^W^W Simon Jeons^W^W Jaeguk Hanse^W^W Ni zhan Chen^W^W^W Wanpeng Li [ I Cc'd Paul Bolle at pebolle@tiscali.nl as well, his English was better from there ] On Thu, Jul 25, 2013 at 02:50:54PM +0800, Paul Bolle wrote: > On 07/23/2013 04:21 AM, Rik van Riel wrote: > >On 07/19/2013 04:55 PM, Johannes Weiner wrote: > > > >>@@ -1984,7 +1992,8 @@ this_zone_full: > >> goto zonelist_scan; > >> } > >> > >>- if (page) > >>+ if (page) { > >>+ atomic_sub(1U << order, &zone->alloc_batch); > >> /* > >> * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was > >> * necessary to allocate the page. The expectation is > > > >Could this be moved into the slow path in buffered_rmqueue and > >rmqueue_bulk, or would the effect of ignoring the pcp buffers be > >too detrimental to keeping the balance between zones? > > > >It would be kind of nice to not have this atomic operation on every > >page allocation... > > atomic operation will lock cache line or memory bus? And cmpxchg > will lock cache line or memory bus? ;-) Sure, why not ;-) -- 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/ . Don't email: email@kvack.org