Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261836AbUKPWEy (ORCPT ); Tue, 16 Nov 2004 17:04:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261858AbUKPWD1 (ORCPT ); Tue, 16 Nov 2004 17:03:27 -0500 Received: from mx1.elte.hu ([157.181.1.137]:15026 "EHLO mx1.elte.hu") by vger.kernel.org with ESMTP id S261836AbUKPWCt (ORCPT ); Tue, 16 Nov 2004 17:02:49 -0500 Date: Wed, 17 Nov 2004 00:03:38 +0100 From: Ingo Molnar To: Florian Schmidt Cc: "K.R. Foley" , Mark_H_Johnson@raytheon.com, linux-kernel@vger.kernel.org, Lee Revell , Rui Nuno Capela , Bill Huey , Adam Heath , Thomas Gleixner , Michal Schmidt , Fernando Pablo Lopez-Lezcano , Karsten Wiese , Gunther Persoons , emann@mrv.com, Shane Shrybman , Amit Shah , Stefan Schweizer Subject: Re: [patch] Real-Time Preemption, -RT-2.6.10-rc2-mm1-V0.7.27-3 Message-ID: <20041116230338.GA31529@elte.hu> References: <20041116184315.GA5492@elte.hu> <419A5A53.6050100@cybsft.com> <20041116212401.GA16845@elte.hu> <20041116222039.662f41ac@mango.fruits.de> <20041116223135.GA27250@elte.hu> <20041116223312.4e289e62@mango.fruits.de> <20041116224023.5067328f@mango.fruits.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20041116224023.5067328f@mango.fruits.de> User-Agent: Mutt/1.4.1i X-ELTE-SpamVersion: MailScanner 4.31.6-itk1 (ELTE 1.2) SpamAssassin 2.63 ClamAV 0.73 X-ELTE-VirusStatus: clean X-ELTE-SpamCheck: no X-ELTE-SpamCheck-Details: score=-4.9, required 5.9, autolearn=not spam, BAYES_00 -4.90 X-ELTE-SpamLevel: X-ELTE-SpamScore: -4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1664 Lines: 43 ah, it's a missed reschedule: > 5 80010004 0.000ms (+0.000ms): trace_start_sched_wakeup (try_to_wake_up) > 5 80010003 0.000ms (+0.000ms): (0) ((98)) > 5 80010003 0.000ms (+0.000ms): (2) ((5)) > 5 80010003 0.000ms (+0.000ms): try_to_wake_up (wake_up_process) > 5 80010003 0.000ms (+0.000ms): (0) ((1)) > 5 80010002 0.000ms (+0.000ms): preempt_schedule (try_to_wake_up) > 5 80010002 0.000ms (+0.000ms): wake_up_process (redirect_hardirq) > 5 80010001 0.000ms (+0.000ms): preempt_schedule (__do_IRQ) > 5 80010001 0.000ms (+0.000ms): irq_exit (do_IRQ) > 5 80000002 0.000ms (+0.000ms): do_softirq (irq_exit) > 5 80000002 0.001ms (+1.054ms): __do_softirq (do_softirq) > 5 00000000 1.055ms (+0.000ms): preempt_schedule (_mmx_memcpy) > 5 90000000 1.055ms (+0.000ms): __schedule (preempt_schedule) note this entry: > 5 80010003 0.000ms (+0.000ms): (0) ((1)) this was generated by: __trace(0, need_resched()); so need_resched() is definite set. The kernel should have rescheduled. The other trace entries corroborate this: > 5 80010003 0.000ms (+0.000ms): (0) ((98)) > 5 80010003 0.000ms (+0.000ms): (2) ((5)) these two entries mean that PID 2 got woken up by PID 5, and that PID 2 has a priority of 0, which is much higher than PID 5's prio 98 [the kernel-internal priority scale is inverted], so no wonder need_resched() is set. Ingo - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/