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| author | Peter Zijlstra <peterz@infradead.org> | 2019-05-29 22:36:43 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2019-08-08 09:09:31 +0200 |
| commit | 5f2a45fc9e89e022233085e6f0f352eb6ff770bb (patch) | |
| tree | 6f619f4db2fe3ab531d4a27807af7f6a8e7d2fe9 /kernel/sched/deadline.c | |
| parent | sched/fair: Expose newidle_balance() (diff) | |
| download | linux-5f2a45fc9e89e022233085e6f0f352eb6ff770bb.tar.xz linux-5f2a45fc9e89e022233085e6f0f352eb6ff770bb.zip | |
sched: Allow put_prev_task() to drop rq->lock
Currently the pick_next_task() loop is convoluted and ugly because of
how it can drop the rq->lock and needs to restart the picking.
For the RT/Deadline classes, it is put_prev_task() where we do
balancing, and we could do this before the picking loop. Make this
possible.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Aaron Lu <aaron.lwe@gmail.com>
Cc: mingo@kernel.org
Cc: Phil Auld <pauld@redhat.com>
Cc: Julien Desfossez <jdesfossez@digitalocean.com>
Cc: Nishanth Aravamudan <naravamudan@digitalocean.com>
Link: https://lkml.kernel.org/r/e4519f6850477ab7f3d257062796e6425ee4ba7c.1559129225.git.vpillai@digitalocean.com
Diffstat (limited to 'kernel/sched/deadline.c')
| -rw-r--r-- | kernel/sched/deadline.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 6eae79350303..2872e15a87cd 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1804,13 +1804,25 @@ pick_next_task_dl(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) return p; } -static void put_prev_task_dl(struct rq *rq, struct task_struct *p) +static void put_prev_task_dl(struct rq *rq, struct task_struct *p, struct rq_flags *rf) { update_curr_dl(rq); update_dl_rq_load_avg(rq_clock_pelt(rq), rq, 1); if (on_dl_rq(&p->dl) && p->nr_cpus_allowed > 1) enqueue_pushable_dl_task(rq, p); + + if (rf && !on_dl_rq(&p->dl) && need_pull_dl_task(rq, p)) { + /* + * This is OK, because current is on_cpu, which avoids it being + * picked for load-balance and preemption/IRQs are still + * disabled avoiding further scheduler activity on it and we've + * not yet started the picking loop. + */ + rq_unpin_lock(rq, rf); + pull_dl_task(rq); + rq_repin_lock(rq, rf); + } } /* |