From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lb0-f179.google.com (mail-lb0-f179.google.com [209.85.217.179]) by kanga.kvack.org (Postfix) with ESMTP id F2BC6900021 for ; Tue, 28 Oct 2014 04:59:19 -0400 (EDT) Received: by mail-lb0-f179.google.com with SMTP id w7so177587lbi.24 for ; Tue, 28 Oct 2014 01:59:19 -0700 (PDT) Received: from mail.ud10.udmedia.de (ud10.udmedia.de. [194.117.254.50]) by mx.google.com with ESMTPS id ra5si1295010lbb.137.2014.10.28.01.59.17 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 28 Oct 2014 01:59:18 -0700 (PDT) Date: Tue, 28 Oct 2014 09:59:16 +0100 From: Markus Trippelsdorf Subject: Re: isolate_freepages_block(): very high intermittent overhead Message-ID: <20141028085916.GA337@x4> References: <20141027204003.GB348@x4> <544EC0C5.7050808@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <544EC0C5.7050808@suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Vlastimil Babka Cc: linux-mm@kvack.org 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. Unfortunately, I don't have time to debug this further and have disabled "Transparent Hugepage Support" for now. -- 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