Re: [PATCH 0/4] cputime: Virtual cputime accounting small cleanups and consolidation

Peter Zijlstra
2012-06-21T08:53:39Z

On Thu, 2012-06-21 at 10:30 +0200, Peter Zijlstra wrote:
> On Thu, 2012-06-21 at 02:46 +0200, Frederic Weisbecker wrote:
> > > So I understand why s390,ia64 want the sched hook, but I don't see why
> > > ppc would need it, their account_process_tick() can fold whatever they
> > > need on the tick.
> >
> > I think in any case you need to flush the time on a descheduling task otherwise
> > its pending time will be accounted later to the next task when it
> > receives an irq.
> >
> > So I fear we still need that sched switch hook even with per cpu data. This
> > may be a simple account_system_vtime() call.
>
> Did I miss a per-task something in there?

Gah yeah.. I was staring too hard at the arch code and missed the task
accounting in the core code.

OK, so that switch hook stays :-)