Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932581AbVJVDoe (ORCPT ); Fri, 21 Oct 2005 23:44:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932582AbVJVDoe (ORCPT ); Fri, 21 Oct 2005 23:44:34 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:33228 "EHLO mx2.mail.elte.hu") by vger.kernel.org with ESMTP id S932581AbVJVDod (ORCPT ); Fri, 21 Oct 2005 23:44:33 -0400 Date: Sat, 22 Oct 2005 05:44:58 +0200 From: Ingo Molnar To: Lee Revell Cc: Mark Knecht , linux-kernel@vger.kernel.org Subject: Re: 2.6.14-rc5-rt3 - `IRQ 8'[798] is being piggy Message-ID: <20051022034458.GB12751@elte.hu> References: <5bdc1c8b0510211003j4e9bf03bhf1ea8e94ffe60153@mail.gmail.com> <5bdc1c8b0510211040s40f3f9bbj7f83e174d7b6d937@mail.gmail.com> <1129920323.17709.2.camel@mindpipe> <5bdc1c8b0510211152m592d95cfte57dc7e9b027f87a@mail.gmail.com> <1129923883.17709.11.camel@mindpipe> <5bdc1c8b0510211525v62212d33j84491cfc687bd200@mail.gmail.com> <1129937318.4724.6.camel@mindpipe> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1129937318.4724.6.camel@mindpipe> 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=disabled SpamAssassin version=3.0.4 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: 1505 Lines: 35 * Lee Revell wrote: > On Fri, 2005-10-21 at 15:25 -0700, Mark Knecht wrote: > > > > > > No I don't think so. CONFIG_RTC_HISTOGRAM is a hack, designed to work > > > with a specific test program that runs SCHED_FIFO and poll()s on the > > > RTC. VLC apparently poll()s on the RTC but does not run SCHED_FIFO. So > > > of course there will be delays. > > > Lee, > > Indeed, you are correct. Apparently under character devices I had > > turned on the RTC histogram feature. With that off I am not only > > getting the maximum latency values we expect. > > > > Now I'll have to let it run for hours/days to see if I catch any > > info on these xruns, should I get another rash of them. Yesterday they > > came only after about 14 hours of work. I had none the previous two > > days. > > In general you should avoid enabling/disabling random config options > between runs. If you keep changing the .config it makes it impossible > to hunt bugs or compare one set of results to another. i think i'll remove the CONFIG_RTC_HISTOGRAM feature altogether from the -rt tree - meanwhile we've got more advanced (and less verbose) latency histogram features via WAKEUP_LATENCY_HIST, PREEMPT_OFF_HIST and INTERRUPT_OFF_HIST. 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/