Messages in this thread | | | Date | Sun, 21 Dec 2008 23:43:36 +0100 | From | "Fabio Comolli" <> | Subject | Re: TSC not updating after resume: Bug or Feature? |
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Hi Thomas.
On Sun, Dec 21, 2008 at 8:43 PM, Thomas Gleixner <tglx@linutronix.de> wrote: > On Sun, 21 Dec 2008, Thomas Gleixner wrote: >> On Thu, 18 Dec 2008, Rafael J. Wysocki wrote: >> > > 5b7dba4: sched_clock: prevent scd->clock from moving backwards >> > > >> > > and the bug triggered by hibernation fixed instead. >> >> Hmm. Depending on the hibernation sleep time we can end up with a >> pretty long delta between the pre suspend and the post resume call to >> __update_sched_clock(). >> >> I have the feeling that sched_clock looks into stale values after >> resume and the first call to __update_sched_clock() trips over the >> stale scd->clock value. Shaggy's patch brings scd->clock into the mix >> and that might cause the whole machinery to blow up on resume. >> >> Also we need to investigate whether sched_clock is referencing gtod >> values _before_ timekeeping is resume. > > I checked the two bugzillas (12149 & 12155) and both reporters have > hpet=force on the command line.
Well, I'm the submitter of bug 12155 and I never had hpet=force on my command line. I don't know where you found it. Actually my command line is:
------------------------------------------------------------------------------------------------------------------------- fcomolli@hawking:~> cat /proc/cmdline root=/dev/sda2 resume=/dev/sda3 i8042.nomux=1 pciehp.pciehp_force=1 quiet splash=silent vga=791 -------------------------------------------------------------------------------------------------------------------------
By the way, I don't know if it matters but the problema happened with in-kernel hibernation and also in out-of-tree TuxOnIce hibernation. Maybe this can help debugging the issue, I don't know.
> > One of the reporters said: "If I de-select CONFIG_HPET_TIMER then the > issue went away ..." > > It looks like this was not further investigated. Is this problem > reproducible on other systems as well ? > > Thanks, > > tglx > --
Regards, Fabio
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