From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with ESMTP id BEE2A6B0012 for ; Wed, 15 Jun 2011 07:42:41 -0400 (EDT) Subject: Re: REGRESSION: Performance regressions from switching anon_vma->lock to mutex From: Peter Zijlstra In-Reply-To: <1308135495.15315.38.camel@twins> References: <1308097798.17300.142.camel@schen9-DESK> <1308134200.15315.32.camel@twins> <1308135495.15315.38.camel@twins> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Date: Wed, 15 Jun 2011 13:41:31 +0200 Message-ID: <1308138091.15315.50.camel@twins> Mime-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: Tim Chen Cc: Andrew Morton , Linus Torvalds , Hugh Dickins , KOSAKI Motohiro , Benjamin Herrenschmidt , David Miller , Martin Schwidefsky , Russell King , Paul Mundt , Jeff Dike , Richard Weinberger , Tony Luck , KAMEZAWA Hiroyuki , Mel Gorman , Nick Piggin , Namhyung Kim , ak@linux.intel.com, shaohua.li@intel.com, alex.shi@intel.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, "Rafael J. Wysocki" , paulmck On Wed, 2011-06-15 at 12:58 +0200, Peter Zijlstra wrote: > On Wed, 2011-06-15 at 12:36 +0200, Peter Zijlstra wrote: > > On Tue, 2011-06-14 at 17:29 -0700, Tim Chen wrote: > > > MOSBENCH test suite. > >=20 > > Argh, I'm trying to get this thing to run, but its all snake poo.. > >=20 > > /me takes up a heavy club and goes snake hunting, should make a pretty > > hat or something. >=20 > Sweet, I've got meself a snake-skin hat! >=20 > The first thing that stood out when running it was: >=20 > 31694 root 20 0 26660 1460 1212 S 17.5 0.0 0:01.97 exim=20 > 7 root -2 19 0 0 0 S 12.7 0.0 0:06.14 rcuc0=20 > 24 root -2 19 0 0 0 S 11.7 0.0 0:04.15 rcuc3=20 > 34 root -2 19 0 0 0 S 11.7 0.0 0:04.10 rcuc5=20 > 39 root -2 19 0 0 0 S 11.7 0.0 0:06.38 rcuc6=20 > 44 root -2 19 0 0 0 S 11.7 0.0 0:04.53 rcuc7=20 > 49 root -2 19 0 0 0 S 11.7 0.0 0:04.11 rcuc8=20 > 79 root -2 19 0 0 0 S 11.7 0.0 0:03.91 rcuc14=20 > 89 root -2 19 0 0 0 S 11.7 0.0 0:03.90 rcuc16=20 > 110 root -2 19 0 0 0 S 11.7 0.0 0:03.90 rcuc20=20 > 120 root -2 19 0 0 0 S 11.7 0.0 0:03.82 rcuc22=20 > 13 root -2 19 0 0 0 S 10.7 0.0 0:04.37 rcuc1=20 > 19 root -2 19 0 0 0 S 10.7 0.0 0:04.19 rcuc2=20 > 29 root -2 19 0 0 0 S 10.7 0.0 0:04.12 rcuc4=20 > 54 root -2 19 0 0 0 S 10.7 0.0 0:04.11 rcuc9=20 > 59 root -2 19 0 0 0 S 10.7 0.0 0:04.40 rcuc10=20 > 64 root -2 19 0 0 0 R 10.7 0.0 0:04.17 rcuc11=20 > 69 root -2 19 0 0 0 R 10.7 0.0 0:04.23 rcuc12=20 > 84 root -2 19 0 0 0 S 10.7 0.0 0:03.90 rcuc15=20 > 95 root -2 19 0 0 0 S 10.7 0.0 0:03.99 rcuc17=20 > 100 root -2 19 0 0 0 S 10.7 0.0 0:03.88 rcuc18=20 > 105 root -2 19 0 0 0 S 10.7 0.0 0:04.14 rcuc19=20 > 125 root -2 19 0 0 0 S 10.7 0.0 0:03.79 rcuc23=20 > 74 root -2 19 0 0 0 S 9.7 0.0 0:04.33 rcuc13=20 > 115 root -2 19 0 0 0 R 9.7 0.0 0:03.82 rcuc21=20 >=20 > Which is an impressive amount of RCU usage.. FWIW, Alex Shi's patch: http://lkml.kernel.org/r/1308029185.15392.147.camel@sli10-conroe Improves the situation to: 3745 root 20 0 26664 1460 1212 S 18.5 0.0 0:01.28 exim=20 39 root -2 19 0 0 0 S 4.9 0.0 0:02.83 rcuc6=20 105 root -2 19 0 0 0 S 4.9 0.0 0:02.79 rcuc19=20 7 root -2 19 0 0 0 S 3.9 0.0 0:02.70 rcuc0=20 13 root -2 19 0 0 0 S 3.9 0.0 0:02.54 rcuc1=20 19 root -2 19 0 0 0 S 3.9 0.0 0:02.76 rcuc2=20 24 root -2 19 0 0 0 S 3.9 0.0 0:02.75 rcuc3=20 ... And throughput increases like: -tip 260.092 messages/sec/core -tip+sirq-rcu 271.078 messages/sec/core -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org