From patchwork Wed Jun 20 09:35:09 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mel Gorman X-Patchwork-Id: 165962 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 9503AB6FD5 for ; Wed, 20 Jun 2012 19:47:27 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755930Ab2FTJrG (ORCPT ); Wed, 20 Jun 2012 05:47:06 -0400 Received: from cantor2.suse.de ([195.135.220.15]:58595 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755877Ab2FTJf3 (ORCPT ); Wed, 20 Jun 2012 05:35:29 -0400 Received: from relay1.suse.de (unknown [195.135.220.254]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx2.suse.de (Postfix) with ESMTP id 4528FA4479; Wed, 20 Jun 2012 11:35:28 +0200 (CEST) From: Mel Gorman To: Andrew Morton Cc: Linux-MM , Linux-Netdev , LKML , David Miller , Neil Brown , Peter Zijlstra , Mike Christie , Eric B Munson , Mel Gorman Subject: [PATCH 06/17] mm: Ignore mempolicies when using ALLOC_NO_WATERMARK Date: Wed, 20 Jun 2012 10:35:09 +0100 Message-Id: <1340184920-22288-7-git-send-email-mgorman@suse.de> X-Mailer: git-send-email 1.7.9.2 In-Reply-To: <1340184920-22288-1-git-send-email-mgorman@suse.de> References: <1340184920-22288-1-git-send-email-mgorman@suse.de> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The reserve is proportionally distributed over all !highmem zones in the system. So we need to allow an emergency allocation access to all zones. In order to do that we need to break out of any mempolicy boundaries we might have. In my opinion that does not break mempolicies as those are user oriented and not system oriented. That is, system allocations are not guaranteed to be within mempolicy boundaries. For instance IRQs do not even have a mempolicy. So breaking out of mempolicy boundaries for 'rare' emergency allocations, which are always system allocations (as opposed to user) is ok. Signed-off-by: Peter Zijlstra Signed-off-by: Mel Gorman --- mm/page_alloc.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index e6c68d3..6c48965 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2349,6 +2349,13 @@ rebalance: /* Allocate without watermarks if the context allows */ if (alloc_flags & ALLOC_NO_WATERMARKS) { + /* + * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds + * the allocation is high priority and these type of + * allocations are system rather than user orientated + */ + zonelist = node_zonelist(numa_node_id(), gfp_mask); + page = __alloc_pages_high_priority(gfp_mask, order, zonelist, high_zoneidx, nodemask, preferred_zone, migratetype);