Messages in this thread | | | Date | Fri, 21 Apr 2017 11:42:40 +0200 | From | luca abeni <> | Subject | Re: [PATCH] sched/deadline: fix switching to -deadline |
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On Fri, 21 Apr 2017 10:39:26 +0100 Juri Lelli <juri.lelli@arm.com> wrote:
> Hi Luca, > > On 20/04/17 21:30, Luca Abeni wrote: > > From: Luca Abeni <luca.abeni@santannapisa.it> > > > > When switching to -deadline, if the scheduling deadline of a task is > > in the past then switched_to_dl() calls setup_new_entity() to > > properly initialize the scheduling deadline and runtime. > > > > The problem is that the task is enqueued _before_ having its > > parameters initialized by setup_new_entity(), and this can cause > > problems. For example, a task with its out-of-date deadline in the > > past will potentially be enqueued as the highest priority one; > > however, its adjusted deadline may not be the earliest one. > > > > This patch fixes the problem by initializing the task's parameters > > before enqueuing it. > > > > Signed-off-by: Luca Abeni <luca.abeni@santannapisa.it> > > Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com> > > --- > > kernel/sched/deadline.c | 12 ++++-------- > > 1 file changed, 4 insertions(+), 8 deletions(-) > > > > diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c > > index a2ce590..ec53d24 100644 > > --- a/kernel/sched/deadline.c > > +++ b/kernel/sched/deadline.c > > @@ -950,6 +950,10 @@ enqueue_dl_entity(struct sched_dl_entity > > *dl_se, update_dl_entity(dl_se, pi_se); > > else if (flags & ENQUEUE_REPLENISH) > > replenish_dl_entity(dl_se, pi_se); > > + else if ((flags & ENQUEUE_RESTORE) && > > Not sure I understand how this works. AFAICT we are doing > __sched_setscheduler() when we want to catch the case of a new > dl_entity (SCHED_{OTHER,FIFO} -> SCHED_DEADLINE}, but queue_flags > (which are passed to enqueue_task()) don't seem to have > ENQUEUE_RESTORE set?
I was under the impression sched_setscheduler() sets ENQUEUE_RESTORE...
Luca
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