From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f71.google.com (mail-lf0-f71.google.com [209.85.215.71]) by kanga.kvack.org (Postfix) with ESMTP id 8FC486B0005 for ; Tue, 26 Apr 2016 13:32:15 -0400 (EDT) Received: by mail-lf0-f71.google.com with SMTP id k200so18804478lfg.1 for ; Tue, 26 Apr 2016 10:32:15 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id t203si4426164wmg.31.2016.04.26.10.32.14 for (version=TLS1 cipher=AES128-SHA bits=128/128); Tue, 26 Apr 2016 10:32:14 -0700 (PDT) Subject: Re: [PATCH 20/28] mm, page_alloc: Shortcut watermark checks for order-0 pages References: <1460710760-32601-1-git-send-email-mgorman@techsingularity.net> <1460711275-1130-1-git-send-email-mgorman@techsingularity.net> <1460711275-1130-8-git-send-email-mgorman@techsingularity.net> From: Vlastimil Babka Message-ID: <571FA61D.60800@suse.cz> Date: Tue, 26 Apr 2016 19:32:13 +0200 MIME-Version: 1.0 In-Reply-To: <1460711275-1130-8-git-send-email-mgorman@techsingularity.net> Content-Type: text/plain; charset=iso-8859-2; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman , Andrew Morton Cc: Jesper Dangaard Brouer , Linux-MM , LKML On 04/15/2016 11:07 AM, Mel Gorman wrote: > Watermarks have to be checked on every allocation including the number of > pages being allocated and whether reserves can be accessed. The reserves > only matter if memory is limited and the free_pages adjustment only applies > to high-order pages. This patch adds a shortcut for order-0 pages that avoids > numerous calculations if there is plenty of free memory yielding the following > performance difference in a page allocator microbenchmark; > > 4.6.0-rc2 4.6.0-rc2 > optfair-v1r20 fastmark-v1r20 > Min alloc-odr0-1 380.00 ( 0.00%) 364.00 ( 4.21%) > Min alloc-odr0-2 273.00 ( 0.00%) 262.00 ( 4.03%) > Min alloc-odr0-4 227.00 ( 0.00%) 214.00 ( 5.73%) > Min alloc-odr0-8 196.00 ( 0.00%) 186.00 ( 5.10%) > Min alloc-odr0-16 183.00 ( 0.00%) 173.00 ( 5.46%) > Min alloc-odr0-32 173.00 ( 0.00%) 165.00 ( 4.62%) > Min alloc-odr0-64 169.00 ( 0.00%) 161.00 ( 4.73%) > Min alloc-odr0-128 169.00 ( 0.00%) 159.00 ( 5.92%) > Min alloc-odr0-256 180.00 ( 0.00%) 168.00 ( 6.67%) > Min alloc-odr0-512 190.00 ( 0.00%) 180.00 ( 5.26%) > Min alloc-odr0-1024 198.00 ( 0.00%) 190.00 ( 4.04%) > Min alloc-odr0-2048 204.00 ( 0.00%) 196.00 ( 3.92%) > Min alloc-odr0-4096 209.00 ( 0.00%) 202.00 ( 3.35%) > Min alloc-odr0-8192 213.00 ( 0.00%) 206.00 ( 3.29%) > Min alloc-odr0-16384 214.00 ( 0.00%) 206.00 ( 3.74%) > > Signed-off-by: Mel Gorman Acked-by: Vlastimil Babka -- 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