diff options
| author | Gabriele Monaco <gmonaco@redhat.com> | 2026-01-13 09:52:01 +0100 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2026-01-13 11:37:52 +0100 |
| commit | ca1e8eede4fc68ce85a9fdce1a6c13ad64933318 (patch) | |
| tree | 0c292186d6032b6844f0867ac4ef6d48ed006e12 /kernel | |
| parent | 1e0a2ba7afb1b60f02599093d84b72ce62ad11c0 (diff) | |
sched/deadline: Fix server stopping with runnable tasks
The deadline server can currently stop due to idle although fair tasks
are runnable. This happens essentially when:
* the server is set to idle, a task wakes up, the server stops
* a task wakes up, the server sets itself to idle and stops right away
Address both cases by clearing the server idle flag whenever a fair task
wakes up and accounting also for pending tasks in the definition of idle.
Fixes: f5a538c07df2 ("sched/deadline: Fix dl_server stop condition")
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260113085159.114226-3-gmonaco@redhat.com
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/deadline.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index e3efc40349f1..b5c19b17e386 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1420,7 +1420,7 @@ update_stats_dequeue_dl(struct dl_rq *dl_rq, struct sched_dl_entity *dl_se, int static void update_curr_dl_se(struct rq *rq, struct sched_dl_entity *dl_se, s64 delta_exec) { - bool idle = rq->curr == rq->idle; + bool idle = idle_rq(rq); s64 scaled_delta_exec; if (unlikely(delta_exec <= 0)) { @@ -1603,8 +1603,8 @@ void dl_server_update(struct sched_dl_entity *dl_se, s64 delta_exec) * | 8 | B:zero_laxity-wait | | | * | | | <---+ | * | +--------------------------------+ | - * | | ^ ^ 2 | - * | | 7 | 2 +--------------------+ + * | | ^ ^ 2 | + * | | 7 | 2, 1 +----------------+ * | v | * | +-------------+ | * +-- | C:idle-wait | -+ @@ -1649,8 +1649,11 @@ void dl_server_update(struct sched_dl_entity *dl_se, s64 delta_exec) * dl_defer_idle = 0 * * - * [1] A->B, A->D + * [1] A->B, A->D, C->B * dl_server_start() + * dl_defer_idle = 0; + * if (dl_server_active) + * return; // [B] * dl_server_active = 1; * enqueue_dl_entity() * update_dl_entity(WAKEUP) @@ -1759,6 +1762,7 @@ void dl_server_update(struct sched_dl_entity *dl_se, s64 delta_exec) * "B:zero_laxity-wait" -> "C:idle-wait" [label="7:dl_server_update_idle"] * "B:zero_laxity-wait" -> "D:running" [label="3:dl_server_timer"] * "C:idle-wait" -> "A:init" [label="8:dl_server_timer"] + * "C:idle-wait" -> "B:zero_laxity-wait" [label="1:dl_server_start"] * "C:idle-wait" -> "B:zero_laxity-wait" [label="2:dl_server_update"] * "C:idle-wait" -> "C:idle-wait" [label="7:dl_server_update_idle"] * "D:running" -> "A:init" [label="4:pick_task_dl"] @@ -1784,6 +1788,7 @@ void dl_server_start(struct sched_dl_entity *dl_se) { struct rq *rq = dl_se->rq; + dl_se->dl_defer_idle = 0; if (!dl_server(dl_se) || dl_se->dl_server_active) return; |