find_lock_later_rq may or not releease rq lock when return later_rq=NULL, but it is fuzzy. If not releasing rq lock, it is unnecessary to re-call pick_next_pushable_dl_task.
Signed-off-by: Peng Hao <[email protected]> --- kernel/sched/deadline.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 997ea7b..8e875ec 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1979,7 +1979,7 @@ static struct rq *find_lock_later_rq(struct task_struct *task, struct rq *rq) !dl_task(task) || !task_on_rq_queued(task))) { double_unlock_balance(rq, later_rq); - later_rq = NULL; + later_rq = RETRY_TASK; break; } } @@ -2063,7 +2063,9 @@ static int push_dl_task(struct rq *rq) /* Will lock the rq it'll find */ later_rq = find_lock_later_rq(next_task, rq); - if (!later_rq) { + if (!later_rq) + goto out; + if (later_rq == RETRY_TASK) { struct task_struct *task; /* -- 1.8.3.1
