Re: Rescheduling interrupts

["S.Çağlar Onur" <caglar@pardus.org.tr>]

Hi;

22 Oca 2008 Sal tarihinde, Ingo Molnar şunları yazmıştı: 
> * S.Çağlar Onur <caglar@pardus.org.tr> wrote:
> > I grabbed the logs two times to make sure to catch needed info. 1st [1]
> > one is generated while "Rescheduling interrupts" wakeups ~200 times and
> > 2nd one generated for ~350 wakeups.
> >
> > [1] http://cekirdek.pardus.org.tr/~caglar/dmesg.1st
> > [2] http://cekirdek.pardus.org.tr/~caglar/dmesg.2nd
>
> thanks, these seem to be mostly normal wakeups from standard tasks:
>
>  IPI from task kdm_greet:2118 on CPU#0:
>  IPI from task X:2079 on CPU#1:
>  IPI from task kdm_greet:2118 on CPU#0:
>  IPI from task hald-addon-inpu:2009 on CPU#1:
>  IPI from task events/0:7 on CPU#1:
>  IPI from task bash:2129 on CPU#0:
>  IPI from task kdm_greet:2118 on CPU#0:
>  IPI from task events/0:7 on CPU#1:
>  IPI from task events/0:7 on CPU#1:
>  IPI from task events/0:7 on CPU#1:
>  IPI from task bash:3902 on CPU#1:
>  IPI from task bash:3902 on CPU#1:
>  IPI from task amarokapp:3423 on CPU#1:
>  IPI from task amarokapp:3423 on CPU#1:
>  IPI from task amarokapp:3423 on CPU#1:
>  IPI from task X:2079 on CPU#0:
>  IPI from task yakuake:3422 on CPU#0:
>  IPI from task X:2079 on CPU#1:
>  IPI from task amarokapp:3423 on CPU#1:
>  IPI from task amarokapp:3423 on CPU#1:
>
> could you also add a similar IPI printouts (with the same panic_timeout
> logic) to arch/x86/kernel/smp_32.c's smp_reschedule_interrupt() function
> - while still keeping the other printouts too?
>
> Could you also enable PRINTK_TIME timestamps, so that we can see the
> timings? (And do a "dmesg -n 1" so that the printks happen fast and the
> timings are accurate.) I'd suggest to increase CONFIG_LOG_BUF_SHIFT to
> 20, so that your dmesg buffer is large enough. Plus try to capture 100
> events, ok?
>
> My theory is that for whatever reason we get "repeat" IPIs: multiple
> reschedule IPIs although the other CPU only initiated one.

Ok, please see http://cekirdek.pardus.org.tr/~caglar/dmesg.3rd :)

Cheers
-- 
S.Çağlar Onur <caglar@pardus.org.tr>
http://cekirdek.pardus.org.tr/~caglar/

Linux is like living in a teepee. No Windows, no Gates and an Apache in house!