Re: [3/3] 2.6.21-rc7: known regressions (v2)

Len Brown
2007-04-26T00:33:05Z

On Wednesday 25 April 2007 14:08, john stultz wrote:
> On Wed, 2007-04-25 at 04:06 -0700, Andrew Morton wrote:
> > On Mon, 23 Apr 2007 23:49:09 +0200 Adrian Bunk <bunk@stusta.de> wrote:
> >
> > > This email lists some known regressions in Linus' tree compared to 2.6.20.
> > >
> > > If you find your name in the Cc header, you are either submitter of one
> > > of the bugs, maintainer of an affectected subsystem or driver, a patch
> > > of you caused a breakage or I'm considering you in any other way
> > > possibly involved with one or more of these issues.
> > >
> > > Due to the huge amount of recipients, please trim the Cc when answering.
> > >
> > >
> > > Subject : HPET enabled freeze my machine at boot
> > > workaround: clocksource=acpi_pm
> > > References : http://lkml.org/lkml/2007/4/19/370
> > > Submitter : Guilherme Schroeder <guilherme@centralinf.com.br>
> > > Caused-By : Thomas Gleixner <tglx@linutronix.de>
> > > commit 5d8b34fdcb384161552d01ee8f34af5ff11f9684
> > > Handled-By : John Stultz <johnstul@us.ibm.com>
> > > Status : problem is being debugged
> > >
> > >
> > > Subject : acpi_pm clocksource loses time on x86-64
> > > References : http://lkml.org/lkml/2007/4/17/143
> > > Submitter : Mikael Pettersson <mikpe@it.uu.se>
> > > Handled-By : John Stultz <johnstul@us.ibm.com>
> > > Status : problem is being debugged
> > >
> > >
> > > Subject : suspend to disk hangs (CONFIG_NO_HZ)
> > > References : http://lkml.org/lkml/2007/3/25/217
> > > Submitter : Jeff Chua <jeff.chua.linux@gmail.com>
> > > Status : unknown
> >
> > That's still rather a lot of bustage from the timekeeping changes. Is
> > anything really happening here or have we all given up?
>
>
> The ACPI PM one is *really* odd as its the same clocksource driver on
> both arches. I had Mikael cut out the clocksource frequency adjustments,
> and confirmed both i386 and x86_64 are using the same base freq
> (confirmed via printks).

If this chipset's PM-timer loses "several minutes per hour" on x86_64,
I would expect it to do the same on i386. I can't imagine what the
difference could be. Any possibility it is the 24-bit version
and we do something funky on wraparound?

-Len

> It almost seems like when booting x86_64 the ACPI PM counter is running
> slowly!
>
> Len: Have you ever heard of such a thing? It seems quite unlikely...
>
>
> WRT the HPET freeze issue, I'm still digging there. In that case it
> appears the HPET isn't counting, so timekeeping just stops. I was
> thinking it might be HRT messing w/ the wrong HPET registers, but so far
> that hasn't shaken out.
>
> I'll spend some more time on these today and see if we get any further.
>
> thanks
> -john
>
>
> -
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