Messages in this thread | | | From | Valentin Schneider <> | Subject | Re: [PATCH 2/2][v2] sched: Extract the task putting code from pick_next_task() | Date | Mon, 20 Apr 2020 18:44:29 +0100 |
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On 20/04/20 16:01, Chen Yu wrote: > Introduce a new function finish_prev_task() to do the balance > when necessary, and then put previous task back to the run queue. > This function is extracted from pick_next_task() to prepare for > future usage by other type of task picking logic. > > No functional change. >
With the absolutely tiny nit below:
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
> Suggested-by: Peter Zijlstra <peterz@infradead.org> > Signed-off-by: Chen Yu <yu.c.chen@intel.com> > --- > kernel/sched/core.c | 39 +++++++++++++++++++++++---------------- > 1 file changed, 23 insertions(+), 16 deletions(-) > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > index 3a61a3b8eaa9..bf59a5cf030c 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -3904,6 +3904,28 @@ static inline void schedule_debug(struct task_struct *prev, bool preempt) > schedstat_inc(this_rq()->sched_count); > } > > +static void finish_prev_task(struct rq *rq, struct task_struct *prev, > + struct rq_flags *rf) > +{ > + const struct sched_class *class; > +#ifdef CONFIG_SMP
Nit: I would've put that declaration within the ifdef, given it isn't used outside of it.
> + /* > + * We must do the balancing pass before put_next_task(), such > + * that when we release the rq->lock the task is in the same > + * state as before we took rq->lock. > + * > + * We can terminate the balance pass as soon as we know there is > + * a runnable task of @class priority or higher. > + */ > + for_class_range(class, prev->sched_class, &idle_sched_class) { > + if (class->balance(rq, prev, rf)) > + break; > + } > +#endif > + > + put_prev_task(rq, prev); > +} > + > /* > * Pick up the highest-prio task: > */
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