From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752660AbYLPJGF (ORCPT ); Tue, 16 Dec 2008 04:06:05 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751225AbYLPJFs (ORCPT ); Tue, 16 Dec 2008 04:05:48 -0500 Received: from mail.gmx.net ([213.165.64.20]:58862 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751158AbYLPJFr (ORCPT ); Tue, 16 Dec 2008 04:05:47 -0500 X-Authenticated: #14349625 X-Provags-ID: V01U2FsdGVkX1+cfiY5HAmc0hL1Oi9I6u/Wzl2Pc1D4sia0zND22R QBPOEy1tdxGUev Subject: Re: [PATCH 3/3] sched: prefer wakers From: Mike Galbraith To: Peter Zijlstra Cc: mingo@elte.hu, linux-kernel@vger.kernel.org In-Reply-To: <20081216074636.176935879@chello.nl> References: <20081216074529.570706654@chello.nl> <20081216074636.176935879@chello.nl> Content-Type: text/plain Date: Tue, 16 Dec 2008 10:05:43 +0100 Message-Id: <1229418343.7438.10.camel@marge.simson.net> Mime-Version: 1.0 X-Mailer: Evolution 2.22.1.1 Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 X-FuHaFi: 0.62 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2008-12-16 at 08:45 +0100, Peter Zijlstra wrote: > plain text document attachment (wakeup-preempt-fiddle.patch) > Prefer tasks that wake other tasks to preempt quickly. This improves > performance because more work is available sooner. > > The workload that prompted this patch was a kernel build over NFS4 (for some > curious and not understood reason we had to revert commit: > 18de9735300756e3ca9c361ef58409d8561dfe0d to make any progress at all) > > Without this patch a make -j8 bzImage (of x86-64 defconfig) would take > 3m30-ish, with this patch we're down to 2m50-ish. Here, with wimpy 100Mbps nic and my normal config, the improvement is considerably larger. Full make -j8 build went from ~6m17s to ~4m28s. -Mike