Messages in this thread | | | Date | Fri, 26 Jul 2019 12:18:19 +0200 | From | luca abeni <> | Subject | Re: [PATCH 5/5] sched/deadline: Use return value of SCHED_WARN_ON() in bw accounting |
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Hi Dietmar,
On Fri, 26 Jul 2019 09:27:56 +0100 Dietmar Eggemann <dietmar.eggemann@arm.com> wrote:
> To make the decision whether to set rq or running bw to 0 in underflow > case use the return value of SCHED_WARN_ON() rather than an extra if > condition.
I think I tried this at some point, but if I remember well this solution does not work correctly when SCHED_DEBUG is not enabled.
Luca
> > Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> > --- > kernel/sched/deadline.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c > index a9cb52ceb761..66c594b5507e 100644 > --- a/kernel/sched/deadline.c > +++ b/kernel/sched/deadline.c > @@ -95,8 +95,7 @@ void __sub_running_bw(u64 dl_bw, struct dl_rq > *dl_rq) > lockdep_assert_held(&(rq_of_dl_rq(dl_rq))->lock); > dl_rq->running_bw -= dl_bw; > - SCHED_WARN_ON(dl_rq->running_bw > old); /* underflow */ > - if (dl_rq->running_bw > old) > + if (SCHED_WARN_ON(dl_rq->running_bw > old)) /* underflow */ > dl_rq->running_bw = 0; > /* kick cpufreq (see the comment in kernel/sched/sched.h). */ > cpufreq_update_util(rq_of_dl_rq(dl_rq), 0); > @@ -119,8 +118,7 @@ void __sub_rq_bw(u64 dl_bw, struct dl_rq *dl_rq) > > lockdep_assert_held(&(rq_of_dl_rq(dl_rq))->lock); > dl_rq->this_bw -= dl_bw; > - SCHED_WARN_ON(dl_rq->this_bw > old); /* underflow */ > - if (dl_rq->this_bw > old) > + if (SCHED_WARN_ON(dl_rq->this_bw > old)) /* underflow */ > dl_rq->this_bw = 0; > SCHED_WARN_ON(dl_rq->running_bw > dl_rq->this_bw); > }
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