Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757256Ab3GVUVQ (ORCPT ); Mon, 22 Jul 2013 16:21:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:14930 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756932Ab3GVUVP (ORCPT ); Mon, 22 Jul 2013 16:21:15 -0400 Message-ID: <51ED9433.60707@redhat.com> Date: Mon, 22 Jul 2013 16:21:07 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: Johannes Weiner CC: Andrew Morton , Mel Gorman , Andrea Arcangeli , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [patch 3/3] mm: page_alloc: fair zone allocator policy References: <1374267325-22865-1-git-send-email-hannes@cmpxchg.org> <1374267325-22865-4-git-send-email-hannes@cmpxchg.org> In-Reply-To: <1374267325-22865-4-git-send-email-hannes@cmpxchg.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: 1234 Lines: 35 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... As a side benefit, higher-order buffered_rmqueue and rmqueue_bulk both happen under the zone->lock, so moving this accounting down to that layer might allow you to get rid of the atomics alltogether. I like the overall approach though. This is something Linux has needed for a long time, and could be extremely useful to automatic NUMA balancing as well... -- All rights reversed -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/