Dear Linux folks,
I got my hands on an old Acer TravelMate 5735Z (Intel GM45/Cantiga) and
installed Debian Sid/unstable with Linux 5.6.7 on it.
Booting the system it takes a long time, and the systemd units fail to
start. The logs contain that the TSC is unstable. Adding `tsc=unstable`
to the Linux kernel command line fixes this.
Do you have an idea, what might cause this? Do you have an idea, what
might cause this, and how it can be fixed?
Kind regards,
Paul
On Sun, May 24, 2020 at 07:09:18PM +0200, Paul Menzel wrote:
> Dear Linux folks,
>
>
> I got my hands on an old Acer TravelMate 5735Z (Intel GM45/Cantiga) and
> installed Debian Sid/unstable with Linux 5.6.7 on it.
>
> Booting the system it takes a long time, and the systemd units fail to
> start. The logs contain that the TSC is unstable. Adding `tsc=unstable` to
> the Linux kernel command line fixes this.
It fixes nothing; it just doesn't get you the warning because you told
it upfront.
> Do you have an idea, what might cause this?
Yes, but you didn't include the dmesg of the affected case. IIRC it
actually spells it out for you.
> Do you have an idea, what might cause this,
It's a Core2, Core2 doesn't have stable TSC.
> and how it can be fixed?
Use a 'better' CPU :-)
Peter Zijlstra <[email protected]> writes:
> On Sun, May 24, 2020 at 07:09:18PM +0200, Paul Menzel wrote:
>> Dear Linux folks,
>>
>>
>> I got my hands on an old Acer TravelMate 5735Z (Intel GM45/Cantiga) and
>> installed Debian Sid/unstable with Linux 5.6.7 on it.
>>
>> Booting the system it takes a long time, and the systemd units fail to
>> start. The logs contain that the TSC is unstable. Adding `tsc=unstable` to
>> the Linux kernel command line fixes this.
>
> It fixes nothing; it just doesn't get you the warning because you told
> it upfront.
Well, it prevents the kernel to use TSC upfront and not wait until it's
discovered to be crap. That might make a difference.
Thanks,
tglx
On Thu, May 28, 2020 at 02:06:17PM +0200, Thomas Gleixner wrote:
> Peter Zijlstra <[email protected]> writes:
> > On Sun, May 24, 2020 at 07:09:18PM +0200, Paul Menzel wrote:
> >> Dear Linux folks,
> >>
> >>
> >> I got my hands on an old Acer TravelMate 5735Z (Intel GM45/Cantiga) and
> >> installed Debian Sid/unstable with Linux 5.6.7 on it.
> >>
> >> Booting the system it takes a long time, and the systemd units fail to
> >> start. The logs contain that the TSC is unstable. Adding `tsc=unstable` to
> >> the Linux kernel command line fixes this.
> >
> > It fixes nothing; it just doesn't get you the warning because you told
> > it upfront.
>
> Well, it prevents the kernel to use TSC upfront and not wait until it's
> discovered to be crap. That might make a difference.
IIRC my Core2 machines bail at boot with the message that TSC stops in
idle. Which is pretty deterministic and avoids userspace wreckage after
the fact, like with the BIOS 'goodness'.