From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753326AbXCWStQ (ORCPT ); Fri, 23 Mar 2007 14:49:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753339AbXCWStQ (ORCPT ); Fri, 23 Mar 2007 14:49:16 -0400 Received: from mga07.intel.com ([143.182.124.22]:11889 "EHLO azsmga101.ch.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753326AbXCWStP (ORCPT ); Fri, 23 Mar 2007 14:49:15 -0400 X-ExtLoop1: 1 X-IronPort-AV: i="4.14,320,1170662400"; d="scan'208"; a="201686755:sNHT839938813" Subject: Re: RSDL 0.31 causes slowdown From: Tim Chen Reply-To: tim.c.chen@linux.intel.com To: Con Kolivas Cc: ck@vds.kolivas.org, linux-kernel@vger.kernel.org, kernel@kolivas.org, wli@holomorphy.com, suresh.b.siddha@intel.com, arjan@infradead.org In-Reply-To: <8cd998d50703221940naec0905y56ec708eb11b81a2@mail.gmail.com> References: <1174598506.23795.62.camel@localhost.localdomain> <8cd998d50703221940naec0905y56ec708eb11b81a2@mail.gmail.com> Content-Type: text/plain Organization: Intel Date: Fri, 23 Mar 2007 09:57:30 -0800 Message-Id: <1174672650.23795.67.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.0.2 (2.0.2-8) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 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