Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758413AbZD3Dhu (ORCPT ); Wed, 29 Apr 2009 23:37:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753004AbZD3Dhk (ORCPT ); Wed, 29 Apr 2009 23:37:40 -0400 Received: from e5.ny.us.ibm.com ([32.97.182.145]:59333 "EHLO e5.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752398AbZD3Dhj (ORCPT ); Wed, 29 Apr 2009 23:37:39 -0400 Subject: Re: TSC marked unstable on suspend and resume From: john stultz To: David Fries Cc: Ingo Molnar , linux-kernel , Thomas Gleixner In-Reply-To: <20090429232523.GO2862@spacedout.fries.net> References: <20090221023943.GA4894@spacedout.fries.net> <1f1b08da0904290945j79e1b578ye415fe4ced259b15@mail.gmail.com> <20090429232523.GO2862@spacedout.fries.net> Content-Type: text/plain Date: Wed, 29 Apr 2009 20:37:33 -0700 Message-Id: <1241062653.7270.44.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.24.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3911 Lines: 115 On Wed, 2009-04-29 at 18:25 -0500, David Fries wrote: > On Wed, Apr 29, 2009 at 09:45:40AM -0700, john stultz wrote: > > On Fri, Feb 20, 2009 at 7:39 PM, David Fries wrote: > > > I'm getting TSC marked as unsable on hibernate to disk with > > > 2.6.29-rc3. ?The last kernel I ran 2.6.24.4 ran 300+ days without a > > > problem and does not loose TSC on hibernate. > > > > > > I'm hibernating with `echo disk > /sys/power/state`. > > > These look like the relavant messages, > > > > > > CPU 0 irqstacks, hard=c0379000 soft=c0378000 > > > PID hash table entries: 1024 (order: 10, 4096 bytes) > > > Fast TSC calibration using PIT > > > Detected 300.705 MHz processor. > > > Calibrating delay loop (skipped), value calculated using timer frequency.. 601.41 BogoMIPS (lpj=300705) > > > hibernate to disk, > > > Restarting tasks ... done. > > > Clocksource tsc unstable (delta = 499883531 ns) > > > > Hmm. Seems like the clocksource watchdog is having some problem > > handling state around hibernate. Yea. This seems to be the case here. There's watchdog code and variables to handle resume properly, but there isn't a corresponding suspend hook, so the resume path doesn't actually change anything. Here's a patch you can try, I only had time to compile test it today, so its untested. Hopefully I didn't miss anything obvious. Thomas, I suspect you intended to have something like the following? Signed-off-by: John Stultz diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index 5a40d14..450431f 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -360,6 +360,7 @@ extern void clocksource_touch_watchdog(void); extern struct clocksource* clocksource_get_next(void); extern void clocksource_change_rating(struct clocksource *cs, int rating); extern void clocksource_resume(void); +extern void clocksource_suspend(void); #ifdef CONFIG_GENERIC_TIME_VSYSCALL extern void update_vsyscall(struct timespec *ts, struct clocksource *c); diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index ecfd7b5..3dbe55f 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -236,6 +236,11 @@ static void clocksource_resume_watchdog(void) set_bit(0, &watchdog_resumed); } +static void clocksource_suspend_watchdog(void) +{ + set_bit(1, &watchdog_resumed); +} + static void clocksource_check_watchdog(struct clocksource *cs) { struct clocksource *cse; @@ -278,6 +283,7 @@ static void clocksource_check_watchdog(struct clocksource *cs) } spin_unlock_irqrestore(&watchdog_lock, flags); } + #else static void clocksource_check_watchdog(struct clocksource *cs) { @@ -286,6 +292,7 @@ static void clocksource_check_watchdog(struct clocksource *cs) } static inline void clocksource_resume_watchdog(void) { } +static inline void clocksource_suspend_watchdog(void) { } #endif /** @@ -321,6 +328,18 @@ void clocksource_touch_watchdog(void) } /** + * clocksource_suspend - suspend the clocksource(s) + */ +void clocksource_suspend(void) +{ + unsigned long flags; + + spin_lock_irqsave(&clocksource_lock, flags); + clocksource_suspend_watchdog(); + spin_unlock_irqrestore(&clocksource_lock, flags); +} + +/** * clocksource_get_next - Returns the selected clocksource * */ diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 687dff4..e39e3d3 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -368,6 +368,7 @@ static int timekeeping_suspend(struct sys_device *dev, pm_message_t state) clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL); + clocksource_suspend(); return 0; } -- 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/