Re: [4/5] 2.6.21-rc4: known regressions (v2)

Thomas Gleixner
2007-03-25T07:29:59Z

On Sun, 2007-03-25 at 09:11 +0200, Michael S. Tsirkin wrote:
> > I lost track of Michaels various nested problems.
> >
> > Michael can you please give a summary on _all_ entries in the
> > regressions list against Linus latest ?
>
> I tested 2 different configurations on my T60:
> - With CONFIG_NO_HZ enabled.
> I tested this on -rc1, and have not retested with CONFIG_NO_HZ since.
> Observed behaviour: the system would not come out of suspend to RAM.
> After I press Fn/F4 the crescent LED starts blinking so it seems Linux started
> doing something.
> This is a problem but not a regression as such, since CONFIG_NO_HZ is new
> in 2.6.21.

It needs to be fixed before 2.6.21 final nevertheless.

> - Without CONFIG_NO_HZ
> I last tested this with cd05a1f818073a623455a58e756c5b419fc98db9.
> After systems comes out of suspend to ram, I observed the following
> behaviour (I used s2ram from console):
> 1. The first disk access takes much longer than with 2.6.20
> 2. System clock does not advance (date always reports the same time)
> 3. After an attempt to switch to X, X starts drawing some windows and then hangs
>
> All 3 issues are new and did not occur under 2.6.20, so this is a regression.
> Attached is a full dmesg from boot to resume.

There is not much interesting to see in the log.

Can you please test the following:

Add "clocksource=acpi_pm" to the kernel commandline.

If this does not change anything, then disable CONFIG_HPET and retry.

One thing in the log is indeed scary:

[ 2.959150] Calibrating delay using timer specific routine.. 20089.12
BogoMIPS (lpj=100445639)

This is after the reboot, but it is not related to your problem. This is
a different problem, which needs urgent attention.

Adrian, can you open a seperate entry for this please ? It is not a new
thing, this can be observed with older kernels as well, but it needs to
be addressed. It probably needs a similar solution as I did for the
local apic timer calibration.

tglx