Messages in this thread | | | From | John Stultz <> | Date | Thu, 21 Dec 2023 13:02:05 -0800 | Subject | Re: [PATCH v7 12/23] sched: Fix proxy/current (push,pull)ability |
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On Thu, Dec 21, 2023 at 7:03 AM Metin Kaya <metin.kaya@arm.com> wrote: > On 20/12/2023 12:18 am, John Stultz wrote: > > +static inline void proxy_tag_curr(struct rq *rq, struct task_struct *next) > > +{ > > + if (sched_proxy_exec()) { > > Should we immediately return in !sched_proxy_exec() case to save one > level of indentation?
Sure.
> > + /* > > + * pick_next_task() calls set_next_task() on the selected task > > + * at some point, which ensures it is not push/pullable. > > + * However, the selected task *and* the ,mutex owner form an > > Super-nit: , before mutex should be dropped. > > > + * atomic pair wrt push/pull. > > + * > > + * Make sure owner is not pushable. Unfortunately we can only > > + * deal with that by means of a dequeue/enqueue cycle. :-/ > > + */ > > + dequeue_task(rq, next, DEQUEUE_NOCLOCK | DEQUEUE_SAVE); > > + enqueue_task(rq, next, ENQUEUE_NOCLOCK | ENQUEUE_RESTORE); > > + } > > +} > > + > > /* > > * __schedule() is the main scheduler function. > > * > > @@ -6796,6 +6813,10 @@ static void __sched notrace __schedule(unsigned int sched_mode) > > * changes to task_struct made by pick_next_task(). > > */ > > RCU_INIT_POINTER(rq->curr, next); > > + > > + if (!task_current_selected(rq, next)) > > + proxy_tag_curr(rq, next); > > + > > /* > > * The membarrier system call requires each architecture > > * to have a full memory barrier after updating > > @@ -6820,6 +6841,10 @@ static void __sched notrace __schedule(unsigned int sched_mode) > > /* Also unlocks the rq: */ > > rq = context_switch(rq, prev, next, &rf); > > } else { > > + /* In case next was already curr but just got blocked_donor*/ > > Super-nit: please keep a space before */.
Fixed up.
Thanks for continuing to provide so much detailed feedback! -john
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