User-mode Linux kernel port

On Friday 29 April 2005 11:59, Suresh wrote:
> Hi
>
> I am running uml with smp support.
> I created 4 threads through kernel_thread.
> I want to run the each thread on a different particular processor.
> I have in the thread I have set currnet->cpus_allowed = to the cpu on which
> it is allowed.
Is this an allowed API? I.e., I don't think that you're allowed to set that so 
simply. In fact, this is what I get on a 2.6.12-rc3 tree.

$ grep cpus_allowed include/linux/sched.h
        cpumask_t cpus_allowed;
extern int set_cpus_allowed(task_t *p, cpumask_t new_mask);
static inline int set_cpus_allowed(task_t *p, cpumask_t new_mask)

Satisfied? Grep is always your friend...
> Some how I seem to run only on cpu1.
How did you verify this? Also, I guess you really mean cpu0 (the first cpu).
> Kindly tell me why is that??
> regards,
>
> Suresh
Hmm, Jeff said that at least interrupts only run on cpu0... however, I won't 
consider this as a real UML bug unless using the correct API does not provide 
the expected results.
-- 
Paolo Giarrusso, aka Blaisorblade
Skype user "PaoloGiarrusso"
Linux registered user n. 292729
http://www.user-mode-linux.org/~blaisorblade

At 05:08 PM 5/1/2005, Blaisorblade wrote:
>On Friday 29 April 2005 11:59, Suresh wrote:
> > Hi
> >
> > I am running uml with smp support.
> > I created 4 threads through kernel_thread.
> > I want to run the each thread on a different particular processor.
> > I have in the thread I have set currnet->cpus_allowed = to the cpu on which
> > it is allowed.
>Is this an allowed API? I.e., I don't think that you're allowed to set 
>that so
>simply. In fact, this is what I get on a 2.6.12-rc3 tree.
>
>$ grep cpus_allowed include/linux/sched.h
>         cpumask_t cpus_allowed;
>extern int set_cpus_allowed(task_t *p, cpumask_t new_mask);
>static inline int set_cpus_allowed(task_t *p, cpumask_t new_mask)

I haven't seen any API for that.

>Satisfied? Grep is always your friend...

Thanks, I missed to set the cpus_runnable to the cpus_allowed.
This indeed helped.

> > Some how I seem to run only on cpu1.
>How did you verify this? Also, I guess you really mean cpu0 (the first cpu).


I verified by printing smp_processor_id. Any way, I found the problem,
and now it is working.
Thanks for that.

> > Kindly tell me why is that??
> > regards,
> >
> > Suresh
>Hmm, Jeff said that at least interrupts only run on cpu0... however, I won't
>consider this as a real UML bug unless using the correct API does not provide
>the expected results.
>--
>Paolo Giarrusso, aka Blaisorblade
>Skype user "PaoloGiarrusso"
>Linux registered user n. 292729
>http://www.user-mode-linux.org/~blaisorblade
>
>
>
>
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