Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261864AbUKPWIM (ORCPT ); Tue, 16 Nov 2004 17:08:12 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261858AbUKPWFf (ORCPT ); Tue, 16 Nov 2004 17:05:35 -0500 Received: from pop.gmx.de ([213.165.64.20]:58285 "HELO mail.gmx.net") by vger.kernel.org with SMTP id S261859AbUKPWDz (ORCPT ); Tue, 16 Nov 2004 17:03:55 -0500 X-Authenticated: #4399952 Date: Tue, 16 Nov 2004 23:04:43 +0100 From: Florian Schmidt To: Ingo Molnar 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: <20041116230443.452497b9@mango.fruits.de> In-Reply-To: <20041116224257.GB27550@elte.hu> References: <20041116184315.GA5492@elte.hu> <419A5A53.6050100@cybsft.com> <20041116212401.GA16845@elte.hu> <20041116222039.662f41ac@mango.fruits.de> <20041116223243.43feddf4@mango.fruits.de> <20041116224257.GB27550@elte.hu> X-Mailer: Sylpheed-Claws 0.9.12b (GTK+ 1.2.10; i386-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2449 Lines: 51 On Tue, 16 Nov 2004 23:42:57 +0100 Ingo Molnar wrote: > this is either a false positive, or we missed a preemption. To see which > one, could you apply the attached patch and try to reproduce this long > trace? The new trace will tell us whether need_resched is set during > that ~1 msec window. hmm, the output doens't look so much different (or am i just blind?). maybe i need to do make clean before building with this patch applied? flo preemption latency trace v1.0.7 on 2.6.10-rc2-mm1-RT-V0.7.27-10 ------------------------------------------------------- latency: 992 us, entries: 22 (22) | [VP:0 KP:1 SP:1 HP:1 #CPUS:1] ----------------- | task: IRQ 0/2, uid:0 nice:0 policy:1 rt_prio:49 ----------------- => started at: try_to_wake_up+0x51/0x170 => ended at: finish_task_switch+0x51/0xb0 =======> 5 80010004 0.000ms (+0.000ms): trace_start_sched_wakeup (try_to_wake_up) 5 88010003 0.000ms (+0.000ms): (50) ((98)) 5 88010003 0.000ms (+0.000ms): (2) ((5)) 5 88010003 0.000ms (+0.000ms): try_to_wake_up (wake_up_process) 5 88010003 0.000ms (+0.000ms): (0) ((1)) 5 88010002 0.000ms (+0.000ms): preempt_schedule (try_to_wake_up) 5 88010002 0.000ms (+0.000ms): wake_up_process (redirect_hardirq) 5 88010001 0.000ms (+0.000ms): preempt_schedule (__do_IRQ) 5 88010001 0.000ms (+0.000ms): irq_exit (do_IRQ) 5 88000002 0.000ms (+0.000ms): do_softirq (irq_exit) 5 88000002 0.001ms (+0.990ms): __do_softirq (do_softirq) 5 08000000 0.991ms (+0.000ms): preempt_schedule (_mmx_memcpy) 5 98000000 0.991ms (+0.000ms): __schedule (preempt_schedule) 5 98000000 0.991ms (+0.000ms): profile_hit (__schedule) 5 98000001 0.991ms (+0.000ms): sched_clock (__schedule) 2 80000002 0.991ms (+0.000ms): __switch_to (__schedule) 2 80000002 0.991ms (+0.000ms): (5) ((2)) 2 80000002 0.992ms (+0.000ms): (98) ((50)) 2 80000002 0.992ms (+0.000ms): finish_task_switch (__schedule) 2 80000001 0.992ms (+0.000ms): trace_stop_sched_switched (finish_task_switch) 2 80000001 0.992ms (+0.001ms): (2) ((50)) 2 80000001 0.993ms (+0.000ms): trace_stop_sched_switched (finish_task_switch) - 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/