From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265264AbUGMOgE (ORCPT ); Tue, 13 Jul 2004 10:36:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265265AbUGMOgE (ORCPT ); Tue, 13 Jul 2004 10:36:04 -0400 Received: from mail.ccur.com ([208.248.32.212]:37641 "EHLO exchange.ccur.com") by vger.kernel.org with ESMTP id S265264AbUGMOgB (ORCPT ); Tue, 13 Jul 2004 10:36:01 -0400 Date: Tue, 13 Jul 2004 10:36:00 -0400 From: Joe Korty To: William Lee Irwin III , linux-kernel@vger.kernel.org Subject: Re: preempt-timing-2.6.8-rc1 Message-ID: <20040713143600.GA22758@tsunami.ccur.com> Reply-To: joe.korty@ccur.com References: <20040713122805.GZ21066@holomorphy.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040713122805.GZ21066@holomorphy.com> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 13, 2004 at 05:28:05AM -0700, William Lee Irwin III wrote: > This patch uses the preemption counter increments and decrements to time > non-preemptible critical sections. > > This is an instrumentation patch intended to help determine the causes of > scheduling latency related to long non-preemptible critical sections. > > Changes from 2.6.7-based patch: > (1) fix unmap_vmas() check correctly this time > (2) add touch_preempt_timing() to cond_resched_lock() > (3) depend on preempt until it's worked out wtf goes wrong without it You preemption-block hold times will improve *enormously* if you move all softirq processing down to the daemon (and possibly raise the daemon to one of the higher SCHED_RR priorities, to compensate for softirq processing no longer happening at interrupt level). Joe