Merge tag 'sched_urgent_for_v6.17_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Borislav Petkov:
- Fix a stall on the CPU offline path due to mis-counting a deadline
server task twice as part of the runqueue's running tasks count
- Fix a realtime tasks starvation case where failure to enqueue a timer
whose expiration time is already in the past would cause repeated
attempts to re-enqueue a deadline server task which leads to starving
the former, realtime one
- Prevent a delayed deadline server task stop from breaking the
per-runqueue bandwidth tracking
- Have a function checking whether the deadline server task has
stopped, return the correct value
* tag 'sched_urgent_for_v6.17_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/deadline: Don't count nr_running for dl_server proxy tasks
sched/deadline: Fix RT task potential starvation when expiry time passed
sched/deadline: Always stop dl-server before changing parameters
sched/deadline: Fix dl_server_stopped()
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index e2d51f4..f253012 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -1496,10 +1496,12 @@ static void update_curr_dl_se(struct rq *rq, struct sched_dl_entity *dl_se, s64
}
if (unlikely(is_dl_boosted(dl_se) || !start_dl_timer(dl_se))) {
- if (dl_server(dl_se))
- enqueue_dl_entity(dl_se, ENQUEUE_REPLENISH);
- else
+ if (dl_server(dl_se)) {
+ replenish_dl_new_period(dl_se, rq);
+ start_dl_timer(dl_se);
+ } else {
enqueue_task_dl(rq, dl_task_of(dl_se), ENQUEUE_REPLENISH);
+ }
}
if (!is_leftmost(dl_se, &rq->dl))
@@ -1611,7 +1613,7 @@ void dl_server_stop(struct sched_dl_entity *dl_se)
static bool dl_server_stopped(struct sched_dl_entity *dl_se)
{
if (!dl_se->dl_server_active)
- return false;
+ return true;
if (dl_se->dl_server_idle) {
dl_server_stop(dl_se);
@@ -1849,7 +1851,9 @@ void inc_dl_tasks(struct sched_dl_entity *dl_se, struct dl_rq *dl_rq)
u64 deadline = dl_se->deadline;
dl_rq->dl_nr_running++;
- add_nr_running(rq_of_dl_rq(dl_rq), 1);
+
+ if (!dl_server(dl_se))
+ add_nr_running(rq_of_dl_rq(dl_rq), 1);
inc_dl_deadline(dl_rq, deadline);
}
@@ -1859,7 +1863,9 @@ void dec_dl_tasks(struct sched_dl_entity *dl_se, struct dl_rq *dl_rq)
{
WARN_ON(!dl_rq->dl_nr_running);
dl_rq->dl_nr_running--;
- sub_nr_running(rq_of_dl_rq(dl_rq), 1);
+
+ if (!dl_server(dl_se))
+ sub_nr_running(rq_of_dl_rq(dl_rq), 1);
dec_dl_deadline(dl_rq, dl_se->deadline);
}
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 3f06ab8..02e16b70 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -376,10 +376,8 @@ static ssize_t sched_fair_server_write(struct file *filp, const char __user *ubu
return -EINVAL;
}
- if (rq->cfs.h_nr_queued) {
- update_rq_clock(rq);
- dl_server_stop(&rq->fair_server);
- }
+ update_rq_clock(rq);
+ dl_server_stop(&rq->fair_server);
retval = dl_server_apply_params(&rq->fair_server, runtime, period, 0);
if (retval)
