Re: [PATCH v10 5/9] sched/fair: Take into account latency priority at wakeup

From: Vincent Guittot
Date: Tue Feb 21 2023 - 09:25:54 EST


On Tue, 21 Feb 2023 at 15:15, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> On Tue, Feb 21, 2023 at 01:52:58PM +0100, Peter Zijlstra wrote:
> > On Fri, Jan 13, 2023 at 03:12:30PM +0100, Vincent Guittot wrote:
> >
> > > diff --git a/include/linux/sched.h b/include/linux/sched.h
> > > index 6c61bde49152..38decae3e156 100644
> > > --- a/include/linux/sched.h
> > > +++ b/include/linux/sched.h
> > > @@ -568,6 +568,8 @@ struct sched_entity {
> > > /* cached value of my_q->h_nr_running */
> > > unsigned long runnable_weight;
> > > #endif
> > > + /* preemption offset in ns */
> > > + long latency_offset;
> >
> > I wonder about the type here; does it make sense to have it depend on
> > the bitness; that is if s32 is big enough on 32bit then surely it is so
> > too on 64bit, and if not, then it should be unconditionally s64.
> >
>
> The cgroup patch has this as 'int'. I'm thinking we ought to be
> consistent :-)

Yes, good point