Messages in this thread Patch in this message | | | From | Chen Yu <> | Subject | [PATCH 2/2][v2] sched: Extract the task putting code from pick_next_task() | Date | Mon, 20 Apr 2020 23:01:55 +0800 |
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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.
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 + /* + * 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: */ @@ -3937,22 +3959,7 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) } restart: -#ifdef CONFIG_SMP - /* - * 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); + finish_prev_task(rq, prev, rf); for_each_class(class) { p = class->pick_next_task(rq); -- 2.17.1
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