From patchwork Fri Jun 22 14:30:32 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mel Gorman X-Patchwork-Id: 166628 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 ABB57B6FA0 for ; Sat, 23 Jun 2012 00:42:34 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758384Ab2FVOay (ORCPT ); Fri, 22 Jun 2012 10:30:54 -0400 Received: from cantor2.suse.de ([195.135.220.15]:33421 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758296Ab2FVOaw (ORCPT ); Fri, 22 Jun 2012 10:30:52 -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 DB5B7A39D2; Fri, 22 Jun 2012 16:30:51 +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 , Eric Dumazet , Sebastian Andrzej Siewior , Mel Gorman Subject: [PATCH 05/16] mm: Only set page->pfmemalloc when ALLOC_NO_WATERMARKS was used Date: Fri, 22 Jun 2012 15:30:32 +0100 Message-Id: <1340375443-22455-6-git-send-email-mgorman@suse.de> X-Mailer: git-send-email 1.7.9.2 In-Reply-To: <1340375443-22455-1-git-send-email-mgorman@suse.de> References: <1340375443-22455-1-git-send-email-mgorman@suse.de> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org __alloc_pages_slowpath() is called when the number of free pages is below the low watermark. If the caller is entitled to use ALLOC_NO_WATERMARKS then the page will be marked page->pfmemalloc. This protects more pages than are strictly necessary as we only need to protect pages allocated below the min watermark (the pfmemalloc reserves). This patch only sets page->pfmemalloc when ALLOC_NO_WATERMARKS was required to allocate the page. [rientjes@google.com: David noticed the problem during review] Signed-off-by: Mel Gorman --- mm/page_alloc.c | 27 ++++++++++++++------------- 1 file changed, 14 insertions(+), 13 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 5c6d9c6..9883cf7 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2085,8 +2085,8 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist, high_zoneidx, - alloc_flags, preferred_zone, - migratetype); + alloc_flags & ~ALLOC_NO_WATERMARKS, + preferred_zone, migratetype); if (page) { preferred_zone->compact_considered = 0; preferred_zone->compact_defer_shift = 0; @@ -2178,8 +2178,8 @@ __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order, retry: page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist, high_zoneidx, - alloc_flags, preferred_zone, - migratetype); + alloc_flags & ~ALLOC_NO_WATERMARKS, + preferred_zone, migratetype); /* * If an allocation failed after direct reclaim, it could be because @@ -2350,8 +2350,17 @@ rebalance: page = __alloc_pages_high_priority(gfp_mask, order, zonelist, high_zoneidx, nodemask, preferred_zone, migratetype); - if (page) + if (page) { + /* + * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was + * necessary to allocate the page. The expectation is + * that the caller is taking steps that will free more + * memory. The caller should avoid the page being used + * for !PFMEMALLOC purposes. + */ + page->pfmemalloc = true; goto got_pg; + } } /* Atomic allocations - we can't balance anything */ @@ -2468,14 +2477,6 @@ nopage: warn_alloc_failed(gfp_mask, order, NULL); return page; got_pg: - /* - * page->pfmemalloc is set when the caller had PFMEMALLOC set, is - * been OOM killed or specified __GFP_MEMALLOC. The expectation is - * that the caller is taking steps that will free more memory. The - * caller should avoid the page being used for !PFMEMALLOC purposes. - */ - page->pfmemalloc = !!(alloc_flags & ALLOC_NO_WATERMARKS); - if (kmemcheck_enabled) kmemcheck_pagealloc_alloc(page, order, gfp_mask);