From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ea0-f170.google.com (mail-ea0-f170.google.com [209.85.215.170]) by kanga.kvack.org (Postfix) with ESMTP id 3D9E66B0031 for ; Thu, 12 Dec 2013 10:34:27 -0500 (EST) Received: by mail-ea0-f170.google.com with SMTP id k10so319879eaj.29 for ; Thu, 12 Dec 2013 07:34:26 -0800 (PST) Received: from mx2.suse.de (cantor2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id l44si24162692eem.124.2013.12.12.07.34.25 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Thu, 12 Dec 2013 07:34:26 -0800 (PST) Date: Thu, 12 Dec 2013 15:34:22 +0000 From: Mel Gorman Subject: Re: [RFC PATCH 0/4] Configurable fair allocation zone policy Message-ID: <20131212153422.GJ11295@suse.de> References: <1386860779-2301-1-git-send-email-mgorman@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1386860779-2301-1-git-send-email-mgorman@suse.de> Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner Cc: Andrew Morton , Dave Hansen , Rik van Riel , Linux-MM , LKML On Thu, Dec 12, 2013 at 03:06:15PM +0000, Mel Gorman wrote: > Commit 81c0a2bb ("mm: page_alloc: fair zone allocator policy") solved a > bug whereby new pages could be reclaimed before old pages because of how > the page allocator and kswapd interacted on the per-zone LRU lists. > > Unfortunately a side-effect missed during review was that it's now very > easy to allocate remote memory on NUMA machines. The problem is that > it is not a simple case of just restoring local allocation policies as > there are genuine reasons why global page aging may be prefereable. It's > still a major change to default behaviour so this patch makes the policy > configurable and sets what I think is a sensible default. > > The patches are on top of some NUMA balancing patches currently in -mm. > The first patch in the series is a patch posted by Johannes that must be > taken into account before any of my patches on top. The last patch of the > series is what alters default behaviour and makes the fair zone allocator > policy configurable. > > Sniff test results based on following kernels > > vanilla 3.13-rc3 stock > instrument-v5r1 NUMA balancing patches just to rule out any conflicts there > lruslabonly-v1r2 Patch 1 only > local-v1r2 Full series > These figures need to be redone. The instrument-v5r1 and later kernels included a debugging patch that increases migration rates to trigger another bug. The figures of local-v1r2 relative to instrument-v5r1 are fine but not relative to 3.13.0-rc3-vanilla -- Mel Gorman 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