From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Frans Pop Subject: Re: [BUG,2.6.28,s390] Fails to boot in Hercules S/390 emulator - hang traced Date: Mon, 23 Mar 2009 01:11:06 +0100 References: <200903080230.10099.elendil@planet.nl> <200903181307.44867.elendil@planet.nl> <1237391338.32698.9.camel@jstultz-laptop> In-Reply-To: <1237391338.32698.9.camel@jstultz-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200903230111.08814.elendil@planet.nl> Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: John Stultz Cc: Martin Schwidefsky , linux-s390@vger.kernel.org, Roman Zippel , Thomas Gleixner , Linux Kernel Mailing List List-ID: On Wednesday 18 March 2009, John Stultz wrote: > > Ever increasing error with tod on 2.6.28.8 (with Martin's patch > > applied): > > 0.672655! timekeeping: clock source changed from jiffies to tod (shift: 12) > > 0.676889! tod/12 (150): xtime.tv: 1237377507/55524946 -> 1237377507/55524947 > > 0.677020! clock->xtime: 0 -> -4096, error: 0 -> -4294967296 > > 0.680788! tod/12 (151): xtime.tv: 1237377507/55524947 -> 1237377507/55524948 [...] > > 491.860765! tod/12 (37189): xtime.tv: 1237377998/55561985 -> 1237377998/55561986 > > 491.860886! clock->xtime: -4096 -> -4096, error: -159081293676544 -> -159085588643840 > > Hrm. Is the box otherwise working ok? The TOD clock should not be > affected by the second issue (one shot mode) discussed. Yes, the box^Wsystem works fine. I've now also seen the eventual correction of the error in action: after 35 mins of uptime clock->multi changed from 1000 to 999 (with tod). So the only issue left, though only indirectly related to the hang, is the initial behavior with clocksource jiffies where clocksource_bigadjust gets called every time update_wall_time is called (I've confirmed that). And possibly the cleanup change of clock->xtime_nsec to S64. I'll happily leave those to you as I readily admit my understanding of the whole timekeeping thing is still very limited. But if you'd like patches tested, feel free to CC me. Thanks again for you excellent work on tracking down the real cause of the hangs. Cheers, FJP