Re: [Xenomai-core] [RFC, PATCH] per-thread exec-time stats

[Jan Kiszka <jan.kiszka@domain.hid>]

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Gilles Chanteperdrix wrote:
> Philippe Gerum wrote:
>  > On Fri, 2006-07-07 at 01:47 +0200, Gilles Chanteperdrix wrote:
>  > > Philippe Gerum wrote:
>  > >  > > +#ifdef CONFIG_XENO_OPT_STATS
>  > >  > > +static inline void xnpod_acc_exec_time(xnsched_t *sched,
>  > >  > > +                                       xnthread_t *threadout)
>  > >  > > +{
>  > >  > > +    xnticks_t now = xntimer_get_rawclock();
>  > >  > > +    threadout->stat.exec_time += now - sched->last_csw;
>  > >  > > +    sched->last_csw = now;
>  > >  > > +}
>  > >  > 
>  > >  > It would be better to only pass the thread pointer, then use the
>  > >  > thread->sched member. This would clearly explain the relationship
>  > >  > between both, and prevent any bugous attempt at mixing things.
>  > > 
>  > > Beware, when xnpod_schedule is called from within
>  > > xnpod_migrate_thread(), the sched pointer of the switched out thread is
>  > > the one of the destination cpu. So, passing the sched and threadout
>  > > pointers to xnpod_acc_exec_time is safer.
>  > 
>  > Nope, the nklock is held by the migrating thread all along until the
>  > switch has actually occured.
> 
> xnpod_acc_exec_time() is called from within xnpod_schedule() that is
> called from within xnpod_migrate_thread() at a time where
> threadout->sched is the wrong pointer.
> 

True, will revert this.

Thanks,
Jan


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