From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f54.google.com (mail-pa0-f54.google.com [209.85.220.54]) by kanga.kvack.org (Postfix) with ESMTP id D05416B0255 for ; Fri, 20 Nov 2015 03:55:04 -0500 (EST) Received: by pacdm15 with SMTP id dm15so110638083pac.3 for ; Fri, 20 Nov 2015 00:55:04 -0800 (PST) Received: from mga14.intel.com (mga14.intel.com. [192.55.52.115]) by mx.google.com with ESMTP id q65si416216pfi.120.2015.11.20.00.55.03 for ; Fri, 20 Nov 2015 00:55:04 -0800 (PST) Subject: Re: hugepage compaction causes performance drop References: <20151119092920.GA11806@aaronlu.sh.intel.com> <564DCEA6.3000802@suse.cz> From: Aaron Lu Message-ID: <564EDFE5.5010709@intel.com> Date: Fri, 20 Nov 2015 16:55:01 +0800 MIME-Version: 1.0 In-Reply-To: <564DCEA6.3000802@suse.cz> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Vlastimil Babka , linux-mm@kvack.org Cc: Huang Ying , Dave Hansen , Tim Chen , lkp@lists.01.org, Andrea Arcangeli , David Rientjes , Joonsoo Kim On 11/19/2015 09:29 PM, Vlastimil Babka wrote: > +CC Andrea, David, Joonsoo > > On 11/19/2015 10:29 AM, Aaron Lu wrote: >> The vmstat and perf-profile are also attached, please let me know if you >> need any more information, thanks. > > Output from vmstat (the tool) isn't much useful here, a periodic "cat > /proc/vmstat" would be much better. No problem. > The perf profiles are somewhat weirdly sorted by children cost (?), but > I noticed a very high cost (46%) in pageblock_pfn_to_page(). This could > be due to a very large but sparsely populated zone. Could you provide > /proc/zoneinfo? Is a one time /proc/zoneinfo enough or also a periodic one? > If the compaction scanners behave strangely due to a bug, enabling the > ftrace compaction tracepoints should help find the cause. That might > produce a very large output, but maybe it would be enough to see some > parts of it (i.e. towards beginning, middle, end of the experiment). I'll see how to do this, never used ftrace before. Thanks for the quick response. Regards, Aaron -- 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