From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f169.google.com (mail-pd0-f169.google.com [209.85.192.169]) by kanga.kvack.org (Postfix) with ESMTP id B927E6B0031 for ; Fri, 22 Nov 2013 11:58:09 -0500 (EST) Received: by mail-pd0-f169.google.com with SMTP id v10so1502338pde.28 for ; Fri, 22 Nov 2013 08:58:09 -0800 (PST) Received: from mga02.intel.com (mga02.intel.com. [134.134.136.20]) by mx.google.com with ESMTP id sn7si20234329pab.283.2013.11.22.08.58.07 for ; Fri, 22 Nov 2013 08:58:08 -0800 (PST) Message-ID: <528F8CE2.1000001@intel.com> Date: Fri, 22 Nov 2013 08:57:06 -0800 From: Dave Hansen MIME-Version: 1.0 Subject: Re: NUMA? bisected performance regression 3.11->3.12 References: <528E8FCE.1000707@intel.com> <20131122052219.GL3556@cmpxchg.org> <528EF744.8040607@intel.com> <20131122063845.GM3556@cmpxchg.org> In-Reply-To: <20131122063845.GM3556@cmpxchg.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner Cc: Linus Torvalds , Linux-MM , Mel Gorman , Rik van Riel , Kevin Hilman , Andrea Arcangeli , Paul Bolle , Zlatko Calusic , Andrew Morton , Tim Chen , Andi Kleen On 11/21/2013 10:38 PM, Johannes Weiner wrote: > On Thu, Nov 21, 2013 at 10:18:44PM -0800, Dave Hansen wrote: >> For what it's worth, I'm pretty convinced that the numbers folks put in >> the SLIT tables are, at best, horribly inconsistent from system to >> system. At worst, they're utter fabrications not linked at all to the >> reality of the actual latencies. > > You mean the reported distances should probably be bigger on this > particular machine? Yeah, or smaller on the others that made us switch zone_reclaim_mode at the place where we do. > But even when correct, zone_reclaim_mode might not be the best > predictor. Just because it's not worth yet to invest direct reclaim > efforts to stay local does not mean that remote references are free. > > I'm currently running some tests with the below draft to see if this > would still leave us with enough fairness. Does the patch restore > performance even with zone_reclaim_mode disabled? Yeah, that at least works for the one test where it's been causing the most trouble. -- 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