3.16.36-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Peter Zijlstra <peterz@xxxxxxxxxxxxx> commit 0ea60c2054fc3b0c3eb68ac4f6884f3ee78d9925 upstream. In order to be able to use pull_dl_task() from a callback, we need to do away with the return value. Since the return value indicates if we should reschedule, do this inside the function. Since not all callers currently do this, this can increase the number of reschedules due rt balancing. Too many reschedules is not a correctness issues, too few are. Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Cc: ktkhai@xxxxxxxxxxxxx Cc: rostedt@xxxxxxxxxxx Cc: juri.lelli@xxxxxxxxx Cc: pang.xunlei@xxxxxxxxxx Cc: oleg@xxxxxxxxxx Cc: wanpeng.li@xxxxxxxxxxxxxxx Cc: umgwanakikbuti@xxxxxxxxx Link: http://lkml.kernel.org/r/20150611124742.859398977@xxxxxxxxxxxxx Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> [Conflicts: kernel/sched/deadline.c] Signed-off-by: Byungchul Park <byungchul.park@xxxxxxx> [bwh: Backported to 3.16: use resched_task() instead of resched_curr()] Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- kernel/sched/deadline.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -252,9 +252,8 @@ static inline bool need_pull_dl_task(str return false; } -static inline int pull_dl_task(struct rq *rq) +static inline void pull_dl_task(struct rq *rq) { - return 0; } static inline void queue_push_tasks(struct rq *rq) @@ -957,7 +956,7 @@ static void check_preempt_equal_dl(struc resched_task(rq->curr); } -static int pull_dl_task(struct rq *this_rq); +static void pull_dl_task(struct rq *this_rq); #endif /* CONFIG_SMP */ @@ -1380,15 +1379,16 @@ static void push_dl_tasks(struct rq *rq) ; } -static int pull_dl_task(struct rq *this_rq) +static void pull_dl_task(struct rq *this_rq) { - int this_cpu = this_rq->cpu, ret = 0, cpu; + int this_cpu = this_rq->cpu, cpu; struct task_struct *p; + bool resched = false; struct rq *src_rq; u64 dmin = LONG_MAX; if (likely(!dl_overloaded(this_rq))) - return 0; + return; /* * Match the barrier from dl_set_overloaded; this guarantees that if we @@ -1443,7 +1443,7 @@ static int pull_dl_task(struct rq *this_ src_rq->curr->dl.deadline)) goto skip; - ret = 1; + resched = true; deactivate_task(src_rq, p, 0); set_task_cpu(p, this_cpu); @@ -1456,7 +1456,8 @@ skip: double_unlock_balance(this_rq, src_rq); } - return ret; + if (resched) + resched_task(this_rq->curr); } /* -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html