Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750825AbWERLYr (ORCPT ); Thu, 18 May 2006 07:24:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751338AbWERLYr (ORCPT ); Thu, 18 May 2006 07:24:47 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:26519 "EHLO mx3.mail.elte.hu") by vger.kernel.org with ESMTP id S1750825AbWERLYq (ORCPT ); Thu, 18 May 2006 07:24:46 -0400 Date: Thu, 18 May 2006 13:24:35 +0200 From: Ingo Molnar To: Darren Hart Cc: =?iso-8859-1?Q?S=E9bastien_Dugu=E9?= , Lee Revell , lkml , Thomas Gleixner , Mike Galbraith , Steven Rostedt , Florian Schmidt Subject: Re: rt20 scheduling latency testcase and failure data Message-ID: <20060518112435.GA10463@elte.hu> References: <200605121924.53917.dvhltc@us.ibm.com> <200605151830.23544.dvhltc@us.ibm.com> <1147764175.3970.33.camel@frecb000686> <200605180214.05690.dvhltc@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200605180214.05690.dvhltc@us.ibm.com> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: 0.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=0.0 required=5.9 tests=AWL autolearn=no SpamAssassin version=3.0.3 0.0 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1203 Lines: 30 * Darren Hart wrote: > yet to see a missed period with the version of the program. While > getting to this point, I did see some things that concerned me: > > sched_la-4856 3D... 4083us!: math_state_restore (device_not_available) > sched_la-4856 3D... 16033us : smp_apic_timer_interrupt (4b3b98e8 0 0) > > Am I reading that right? 12ms to complete math_state_restore()? What > does "device_not_available" mean here? no - the kernel returned to userspace after doing the math_state_restore, and the next thing you saw is the timer IRQ. The tracer traces function entries, but not function exits. > Here are some other similar traces: > > sched_la-5008 2D... 4104us!: math_state_restore (device_not_available) > sched_la-5008 2.... 4992us > sys_clock_gettime (00000001 b7fc8378 0000007b) same here: we returned to userspace after FPU restore, and the next thing was a sys_clock_gettime() syscall ~800 usecs later. 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/