From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ee0-f41.google.com (mail-ee0-f41.google.com [74.125.83.41]) by kanga.kvack.org (Postfix) with ESMTP id 049096B003A for ; Fri, 18 Apr 2014 11:49:21 -0400 (EDT) Received: by mail-ee0-f41.google.com with SMTP id t10so1765516eei.28 for ; Fri, 18 Apr 2014 08:49:21 -0700 (PDT) Received: from mx2.suse.de (cantor2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id g45si40741409eev.340.2014.04.18.08.49.20 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 18 Apr 2014 08:49:20 -0700 (PDT) Date: Fri, 18 Apr 2014 17:49:18 +0200 From: Michal Hocko Subject: Re: [PATCH 0/2] Disable zone_reclaim_mode by default Message-ID: <20140418154918.GD4523@dhcp22.suse.cz> References: <1396910068-11637-1-git-send-email-mgorman@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1396910068-11637-1-git-send-email-mgorman@suse.de> Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Andrew Morton , Robert Haas , Josh Berkus , Andres Freund , Christoph Lameter , Linux-MM , LKML On Mon 07-04-14 23:34:26, Mel Gorman wrote: > When it was introduced, zone_reclaim_mode made sense as NUMA distances > punished and workloads were generally partitioned to fit into a NUMA > node. NUMA machines are now common but few of the workloads are NUMA-aware > and it's routine to see major performance due to zone_reclaim_mode being > disabled but relatively few can identify the problem. > > Those that require zone_reclaim_mode are likely to be able to detect when > it needs to be enabled and tune appropriately so lets have a sensible > default for the bulk of users. > > Documentation/sysctl/vm.txt | 17 +++++++++-------- > include/linux/mmzone.h | 1 - > mm/page_alloc.c | 17 +---------------- > 3 files changed, 10 insertions(+), 25 deletions(-) Auto-enabling caused so many reports in the past that it is definitely much better to not be clever and let admins enable zone_reclaim where it is appropriate instead. For both patches. Acked-by: Michal Hocko -- Michal Hocko SUSE Labs -- 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