From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f169.google.com (mail-wi0-f169.google.com [209.85.212.169]) by kanga.kvack.org (Postfix) with ESMTP id 743536B0099 for ; Thu, 6 Nov 2014 06:53:25 -0500 (EST) Received: by mail-wi0-f169.google.com with SMTP id n3so1180623wiv.2 for ; Thu, 06 Nov 2014 03:53:24 -0800 (PST) Received: from mail.ud10.udmedia.de (ud10.udmedia.de. [194.117.254.50]) by mx.google.com with ESMTPS id j16si9496797wic.43.2014.11.06.03.53.24 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 06 Nov 2014 03:53:24 -0800 (PST) Date: Thu, 6 Nov 2014 12:53:22 +0100 From: Markus Trippelsdorf Subject: Re: isolate_freepages_block(): very high intermittent overhead Message-ID: <20141106115322.GA17467@x4> References: <20141027204003.GB348@x4> <544EC0C5.7050808@suse.cz> <20141028085916.GA337@x4> <545B5E90.6070902@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <545B5E90.6070902@suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Vlastimil Babka Cc: linux-mm@kvack.org On 2014.11.06 at 12:42 +0100, Vlastimil Babka wrote: > On 10/28/2014 09:59 AM, Markus Trippelsdorf wrote: > > On 2014.10.27 at 23:01 +0100, Vlastimil Babka wrote: > >> On 10/27/2014 09:40 PM, Markus Trippelsdorf wrote: > >> > On my v3.18-rc2 kernel isolate_freepages_block() sometimes shows up very > >> > high (>20%) in perf top during the configuration phase of software > >> > builds. It increases build time considerably. > >> > > >> > Unfortunately the issue is not 100% reproducible, because it appears > >> > only intermittently. And the symptoms vanish after a few minutes. > >> > >> Does it happen for long enough so you can capture it by perf record -g ? > > > > It only happens when I use the "Lockless Allocator": > > http://locklessinc.com/downloads/lockless_allocator_src.tgz > > > > I use: LD_PRELOAD=/usr/lib/libllalloc.so.1.3 when building software, > > because it gives me a ~8% speed boost over glibc's malloc. > > I tried the allocator while updating my gentoo desktop with 3.18-rc3 and adding > some extra memory pressure, but didn't observe anything like this. It could be > system specific. If you do't have the time to debug, can you at least send me > output of "cat /proc/zoneinfo"? I will try to debug this further this weekend. BTW there is an interesting thread on LKML that might be related to this issue: https://lkml.org/lkml/2014/11/4/904 -- Markus -- 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