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| author |   Juri Lelli <juri.lelli@redhat.com> | 2021-02-08 08:35:54 +0100 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2021-02-17 14:12:42 +0100 |
| commit | e0ee463c93c43b1657ad69cf2678ff5bf1b754fe (patch) | |
| tree | d2adb4faf2fd97e0df50a6ad64f6ab625343f13a /kernel/sched/deadline.c | |
| parent | sched/features: Fix hrtick reprogramming (diff) | |
| download | linux-dev-e0ee463c93c43b1657ad69cf2678ff5bf1b754fe.tar.xz linux-dev-e0ee463c93c43b1657ad69cf2678ff5bf1b754fe.zip | |
sched/features: Distinguish between NORMAL and DEADLINE hrtick
The HRTICK feature has traditionally been servicing configurations that
need precise preemptions point for NORMAL tasks. More recently, the
feature has been extended to also service DEADLINE tasks with stringent
runtime enforcement needs (e.g., runtime < 1ms with HZ=1000).
Enabling HRTICK sched feature currently enables the additional timer and
task tick for both classes, which might introduced undesired overhead
for no additional benefit if one needed it only for one of the cases.
Separate HRTICK sched feature in two (and leave the traditional case
name unmodified) so that it can be selectively enabled when needed.
With:
$ echo HRTICK > /sys/kernel/debug/sched_features
the NORMAL/fair hrtick gets enabled.
With:
$ echo HRTICK_DL > /sys/kernel/debug/sched_features
the DEADLINE hrtick gets enabled.
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20210208073554.14629-3-juri.lelli@redhat.com
Diffstat (limited to 'kernel/sched/deadline.c')
| -rw-r--r-- | kernel/sched/deadline.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 6f377969fa71..aac3539aa0fe 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1832,7 +1832,7 @@ static void set_next_task_dl(struct rq *rq, struct task_struct *p, bool first) if (!first) return; - if (hrtick_enabled(rq)) + if (hrtick_enabled_dl(rq)) start_hrtick_dl(rq, p); if (rq->curr->sched_class != &dl_sched_class) @@ -1895,7 +1895,7 @@ static void task_tick_dl(struct rq *rq, struct task_struct *p, int queued) * not being the leftmost task anymore. In that case NEED_RESCHED will * be set and schedule() will start a new hrtick for the next task. */ - if (hrtick_enabled(rq) && queued && p->dl.runtime > 0 && + if (hrtick_enabled_dl(rq) && queued && p->dl.runtime > 0 && is_leftmost(p, &rq->dl)) start_hrtick_dl(rq, p); } |