On Sat, 6 Oct 2018 09:08:37 +0800 Peng Hao <[email protected]> wrote:
> 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]> Reviewed-by: Steven Rostedt (VMware) <[email protected]> -- Steve > --- > 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; > > /*
