Re: [PATCH] N1int for interactivity

Con Kolivas (kernel@kolivas.org)
Tue, 15 Jul 2003 14:03:33 +1000


On Tue, 15 Jul 2003 13:59, Andrew Morton wrote:
> Con Kolivas <kernel@kolivas.org> wrote:
> > I've modified Mike Galbraith's nanosleep work for greater resolution to
> > help the interactivity estimator work I've done in the O*int patches.
> >
> > +inline void __scheduler_tick(runqueue_t *rq, task_t *p)
>
> Two callsites, this guy shouldn't be inlined.
>
> Should it have static scope? The code as-is generates a third copy...
>
> > static unsigned long long monotonic_clock_tsc(void)
> > {
> > unsigned long long last_offset, this_offset, base;
> > -
> > + unsigned long flags;
> > +
> > /* atomically read monotonic base & last_offset */
> > - read_lock_irq(&monotonic_lock);
> > + read_lock_irqsave(&monotonic_lock, flags);
> > last_offset = ((unsigned long long)last_tsc_high<<32)|last_tsc_low;
> > base = monotonic_base;
> > - read_unlock_irq(&monotonic_lock);
> > + read_unlock_irqrestore(&monotonic_lock, flags);
> >
> > /* Read the Time Stamp Counter */
>
> Why do we need to take a global lock here? Can't we use
> get_cycles() or something?
>
>
> Have all the other architectures been reviewed to see if they need this
> change?

I'm calling for help here. This is getting way out of my depth; I've simply
applied Mike's patch.

Con

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