From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933212AbXCZBOK (ORCPT ); Sun, 25 Mar 2007 21:14:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933298AbXCZBOK (ORCPT ); Sun, 25 Mar 2007 21:14:10 -0400 Received: from mail28.syd.optusnet.com.au ([211.29.133.169]:39802 "EHLO mail28.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933212AbXCZBOJ (ORCPT ); Sun, 25 Mar 2007 21:14:09 -0400 From: Con Kolivas To: tim.c.chen@linux.intel.com Subject: Re: RSDL 0.31 causes slowdown Date: Mon, 26 Mar 2007 11:13:47 +1000 User-Agent: KMail/1.9.5 Cc: Con Kolivas , ck@vds.kolivas.org, linux-kernel@vger.kernel.org, wli@holomorphy.com, suresh.b.siddha@intel.com, arjan@infradead.org References: <1174598506.23795.62.camel@localhost.localdomain> <8cd998d50703221940naec0905y56ec708eb11b81a2@mail.gmail.com> <1174672650.23795.67.camel@localhost.localdomain> In-Reply-To: <1174672650.23795.67.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200703261113.47681.kernel@kolivas.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Saturday 24 March 2007 04:57, Tim Chen wrote: > On Fri, 2007-03-23 at 13:40 +1100, Con Kolivas wrote: > > Volanomark is a purely yield() semantic dependant workload (as > > discussed many times previously). In the earlier form of RSDL I > > softened the effect of sched_yield but other changes since then have > > made that softness bordering on a noop. Obviously when sched_yield is > > relied upon that will not be enough. Extending the rr interval simply > > makes the yield slightly more effective and is not the proper > > workaround. Since expiration of arrays is a regular frequent > > occurrence in RSDL then changing yield semantics back to expiration > > should cause a massive improvement in these values, without making the > > yields as long as in mainline. It's impossible to know exactly what > > the final result will be since java uses this timing sensitive yield > > for locking but we can improve it drastically from this. I'll make a > > patch soon to change yield again. > > Con, > > The new RSDL 0.33 has fully recovered the loss in performance for > Volanomark. The throughput for Volanomark is at the same level as > mainline 2.6.21-rc4 kernel. > > Tim Thanks very much for testing. I'm quite happy with the yield semantics staying the way they are in rSDl 0.33+. -- -ck