Messages in this thread | | | From | Abdulla Bubshait <> | Subject | Re: AMD64 X2 lost ticks on PM timer | Date | Tue, 28 Feb 2006 10:41:27 +0300 |
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On Tuesday 28 February 2006 01:47, Jason Baron wrote: > On Mon, 27 Feb 2006, Bill Rugolsky Jr. wrote: > > On Tue, Feb 28, 2006 at 12:22:40AM +0300, bubshait wrote: > > > Losing some ticks... checking if CPU frequency changed. > > > warning: many lost ticks. > > > Your time source seems to be instable or some driver is hogging > > > interupts rip __do_softirq+0x47/0xd1 > > > > > > adding report_lost_ticks only prints repeating messages like > > > > > > Lost 3 timer tick(s)! rip __do_softirq+0x47/0xd1 > > > > I'm seeing tons of these on a Tyan 2895 (Nvidia CKO4) running FC4 with > > kernel-2.6.15-1.1830 (2.6.15.2) SMP: > > > > time.c: Lost 1 timer tick(s)! rip default_idle+0x37/0x7a) > > time.c: Lost 2 timer tick(s)! rip __do_softirq+0x55/0xd4) > > > > [I've seen the same thing with earlier FC 2.6.14 kernels.] > > > > On our systems the __do_softirq messages are strongly correlated with > > sata_nv interrupts, especially during our nightly tripwire-like fs > > checksum job. Unfortunately, the log messages are not very informative. > > I'm not sure what ever happened to the following patch, > > > > http://www.kernel.org/pub/linux/kernel/people/akpm/patches/2.5/2.5.64/2.5 > >.64-mm3/broken-out/report-lost-ticks.patch > > > > but it was dropped. > > > > Unfortunately, I need to spend tomorrow patching kernels in search of a > > fix or workaround, as I have to start using these boxes in production, > > and they need to keep time. > > passing 'nohpet' and/or 'nopmtimer' will force the use of a different > timer...but this is certainly a workaround, if it helps...
Unfortunately, I can't seem to find a way to force it to use hpet. Passing 'notsc' and 'nopmtimer' I end up using PIT/TSC based timekeeping. TSC is already known to have problems with dual core. But I will sit with it for a while to see if it fairs better than the pm timer.
Bill, What timer do you use, and do these lost ticks persist after sata_nv interrupts stop? - 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/
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