+++ /dev/null
-From c0a825f92d92fdccff156fd030efa068df138577 Mon Sep 17 00:00:00 2001
-From: Sasha Levin <sashal@kernel.org>
-Date: Tue, 20 May 2025 11:19:30 +0200
-Subject: sched/deadline: Less agressive dl_server handling
-
-From: Peter Zijlstra <peterz@infradead.org>
-
-[ Upstream commit cccb45d7c4295bbfeba616582d0249f2d21e6df5 ]
-
-Chris reported that commit 5f6bd380c7bd ("sched/rt: Remove default
-bandwidth control") caused a significant dip in his favourite
-benchmark of the day. Simply disabling dl_server cured things.
-
-His workload hammers the 0->1, 1->0 transitions, and the
-dl_server_{start,stop}() overhead kills it -- fairly obviously a bad
-idea in hind sight and all that.
-
-Change things around to only disable the dl_server when there has not
-been a fair task around for a whole period. Since the default period
-is 1 second, this ensures the benchmark never trips this, overhead
-gone.
-
-Fixes: 557a6bfc662c ("sched/fair: Add trivial fair server")
-Reported-by: Chris Mason <clm@meta.com>
-Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
-Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
-Acked-by: Juri Lelli <juri.lelli@redhat.com>
-Link: https://lkml.kernel.org/r/20250702121158.465086194@infradead.org
-Signed-off-by: Sasha Levin <sashal@kernel.org>
----
- include/linux/sched.h | 1 +
- kernel/sched/deadline.c | 25 ++++++++++++++++++++++---
- kernel/sched/fair.c | 9 ---------
- 3 files changed, 23 insertions(+), 12 deletions(-)
-
-diff --git a/include/linux/sched.h b/include/linux/sched.h
-index f96ac1982893..1f92572b20c0 100644
---- a/include/linux/sched.h
-+++ b/include/linux/sched.h
-@@ -702,6 +702,7 @@ struct sched_dl_entity {
- unsigned int dl_defer : 1;
- unsigned int dl_defer_armed : 1;
- unsigned int dl_defer_running : 1;
-+ unsigned int dl_server_idle : 1;
-
- /*
- * Bandwidth enforcement timer. Each -deadline task has its
-diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
-index 89019a140826..094134c9b135 100644
---- a/kernel/sched/deadline.c
-+++ b/kernel/sched/deadline.c
-@@ -1215,6 +1215,8 @@ static void __push_dl_task(struct rq *rq, struct rq_flags *rf)
- /* a defer timer will not be reset if the runtime consumed was < dl_server_min_res */
- static const u64 dl_server_min_res = 1 * NSEC_PER_MSEC;
-
-+static bool dl_server_stopped(struct sched_dl_entity *dl_se);
-+
- static enum hrtimer_restart dl_server_timer(struct hrtimer *timer, struct sched_dl_entity *dl_se)
- {
- struct rq *rq = rq_of_dl_se(dl_se);
-@@ -1234,6 +1236,7 @@ static enum hrtimer_restart dl_server_timer(struct hrtimer *timer, struct sched_
-
- if (!dl_se->server_has_tasks(dl_se)) {
- replenish_dl_entity(dl_se);
-+ dl_server_stopped(dl_se);
- return HRTIMER_NORESTART;
- }
-
-@@ -1639,8 +1642,10 @@ void dl_server_update_idle_time(struct rq *rq, struct task_struct *p)
- void dl_server_update(struct sched_dl_entity *dl_se, s64 delta_exec)
- {
- /* 0 runtime = fair server disabled */
-- if (dl_se->dl_runtime)
-+ if (dl_se->dl_runtime) {
-+ dl_se->dl_server_idle = 0;
- update_curr_dl_se(dl_se->rq, dl_se, delta_exec);
-+ }
- }
-
- void dl_server_start(struct sched_dl_entity *dl_se)
-@@ -1663,7 +1668,7 @@ void dl_server_start(struct sched_dl_entity *dl_se)
- setup_new_dl_entity(dl_se);
- }
-
-- if (!dl_se->dl_runtime)
-+ if (!dl_se->dl_runtime || dl_se->dl_server_active)
- return;
-
- dl_se->dl_server_active = 1;
-@@ -1684,6 +1689,20 @@ void dl_server_stop(struct sched_dl_entity *dl_se)
- dl_se->dl_server_active = 0;
- }
-
-+static bool dl_server_stopped(struct sched_dl_entity *dl_se)
-+{
-+ if (!dl_se->dl_server_active)
-+ return false;
-+
-+ if (dl_se->dl_server_idle) {
-+ dl_server_stop(dl_se);
-+ return true;
-+ }
-+
-+ dl_se->dl_server_idle = 1;
-+ return false;
-+}
-+
- void dl_server_init(struct sched_dl_entity *dl_se, struct rq *rq,
- dl_server_has_tasks_f has_tasks,
- dl_server_pick_f pick_task)
-@@ -2435,7 +2454,7 @@ static struct task_struct *__pick_task_dl(struct rq *rq)
- if (dl_server(dl_se)) {
- p = dl_se->server_pick_task(dl_se);
- if (!p) {
-- if (dl_server_active(dl_se)) {
-+ if (!dl_server_stopped(dl_se)) {
- dl_se->dl_yielded = 1;
- update_curr_dl_se(rq, dl_se, 0);
- }
-diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
-index 138d9f4658d5..9746eff2eff7 100644
---- a/kernel/sched/fair.c
-+++ b/kernel/sched/fair.c
-@@ -5886,7 +5886,6 @@ static bool throttle_cfs_rq(struct cfs_rq *cfs_rq)
- struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg);
- struct sched_entity *se;
- long queued_delta, runnable_delta, idle_delta, dequeue = 1;
-- long rq_h_nr_queued = rq->cfs.h_nr_queued;
-
- raw_spin_lock(&cfs_b->lock);
- /* This will start the period timer if necessary */
-@@ -5970,10 +5969,6 @@ static bool throttle_cfs_rq(struct cfs_rq *cfs_rq)
-
- /* At this point se is NULL and we are at root level*/
- sub_nr_running(rq, queued_delta);
--
-- /* Stop the fair server if throttling resulted in no runnable tasks */
-- if (rq_h_nr_queued && !rq->cfs.h_nr_queued)
-- dl_server_stop(&rq->fair_server);
- done:
- /*
- * Note: distribution will already see us throttled via the
-@@ -7067,7 +7062,6 @@ static void set_next_buddy(struct sched_entity *se);
- static int dequeue_entities(struct rq *rq, struct sched_entity *se, int flags)
- {
- bool was_sched_idle = sched_idle_rq(rq);
-- int rq_h_nr_queued = rq->cfs.h_nr_queued;
- bool task_sleep = flags & DEQUEUE_SLEEP;
- bool task_delayed = flags & DEQUEUE_DELAYED;
- struct task_struct *p = NULL;
-@@ -7151,9 +7145,6 @@ static int dequeue_entities(struct rq *rq, struct sched_entity *se, int flags)
-
- sub_nr_running(rq, h_nr_queued);
-
-- if (rq_h_nr_queued && !rq->cfs.h_nr_queued)
-- dl_server_stop(&rq->fair_server);
--
- /* balance early to pull high priority tasks */
- if (unlikely(!was_sched_idle && sched_idle_rq(rq)))
- rq->next_balance = jiffies;
---
-2.39.5
-
Link: https://lore.kernel.org/r/20250627115118.438797-3-juri.lelli@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
- kernel/sched/deadline.c | 7 +++++++
+ kernel/sched/deadline.c | 7 +++++++
1 file changed, 7 insertions(+)
-diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
-index ef5b5c045769..135580a41e14 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
-@@ -3007,7 +3007,14 @@ void dl_clear_root_domain(struct root_domain *rd)
+@@ -2976,7 +2976,14 @@ void dl_clear_root_domain(struct root_do
int i;
guard(raw_spinlock_irqsave)(&rd->dl_bw.lock);
/*
* dl_servers are not tasks. Since dl_add_task_root_domain ignores
---
-2.39.5
-
drm-rockchip-vop2-fail-cleanly-if-missing-a-primary-.patch
drm-rockchip-vop2-fix-the-update-of-layer-port-selec.patch
sched-psi-optimize-psi_group_change-cpu_clock-usage.patch
-sched-deadline-less-agressive-dl_server-handling.patch
fbcon-fix-outdated-registered_fb-reference-in-commen.patch
netfilter-nf_tables-drop-dead-code-from-fill_-_info-.patch
netfilter-nf_tables-adjust-lockdep-assertions-handli.patch
net_sched-act_ctinfo-use-atomic64_t-for-three-counte.patch
rdma-mlx5-fix-umr-modifying-of-mkey-page-size.patch
xen-fix-uaf-in-dmabuf_exp_from_pages.patch
-sched-deadline-initialize-dl_servers-after-smp.patch
sched-deadline-reset-extra_bw-to-max_bw-when-clearin.patch
iommu-vt-d-do-not-wipe-out-the-page-table-nid-when-d.patch
iommu-arm-smmu-disable-prr-on-sm8250.patch
+++ /dev/null
-From d92f16b1d33db49aad293ba7bb82c53571cc1a2e Mon Sep 17 00:00:00 2001
-From: Sasha Levin <sashal@kernel.org>
-Date: Tue, 20 May 2025 11:19:30 +0200
-Subject: sched/deadline: Less agressive dl_server handling
-
-From: Peter Zijlstra <peterz@infradead.org>
-
-[ Upstream commit cccb45d7c4295bbfeba616582d0249f2d21e6df5 ]
-
-Chris reported that commit 5f6bd380c7bd ("sched/rt: Remove default
-bandwidth control") caused a significant dip in his favourite
-benchmark of the day. Simply disabling dl_server cured things.
-
-His workload hammers the 0->1, 1->0 transitions, and the
-dl_server_{start,stop}() overhead kills it -- fairly obviously a bad
-idea in hind sight and all that.
-
-Change things around to only disable the dl_server when there has not
-been a fair task around for a whole period. Since the default period
-is 1 second, this ensures the benchmark never trips this, overhead
-gone.
-
-Fixes: 557a6bfc662c ("sched/fair: Add trivial fair server")
-Reported-by: Chris Mason <clm@meta.com>
-Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
-Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
-Acked-by: Juri Lelli <juri.lelli@redhat.com>
-Link: https://lkml.kernel.org/r/20250702121158.465086194@infradead.org
-Signed-off-by: Sasha Levin <sashal@kernel.org>
----
- include/linux/sched.h | 1 +
- kernel/sched/deadline.c | 25 ++++++++++++++++++++++---
- kernel/sched/fair.c | 9 ---------
- 3 files changed, 23 insertions(+), 12 deletions(-)
-
-diff --git a/include/linux/sched.h b/include/linux/sched.h
-index aa9c5be7a632..ae75562cca59 100644
---- a/include/linux/sched.h
-+++ b/include/linux/sched.h
-@@ -701,6 +701,7 @@ struct sched_dl_entity {
- unsigned int dl_defer : 1;
- unsigned int dl_defer_armed : 1;
- unsigned int dl_defer_running : 1;
-+ unsigned int dl_server_idle : 1;
-
- /*
- * Bandwidth enforcement timer. Each -deadline task has its
-diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
-index 89019a140826..094134c9b135 100644
---- a/kernel/sched/deadline.c
-+++ b/kernel/sched/deadline.c
-@@ -1215,6 +1215,8 @@ static void __push_dl_task(struct rq *rq, struct rq_flags *rf)
- /* a defer timer will not be reset if the runtime consumed was < dl_server_min_res */
- static const u64 dl_server_min_res = 1 * NSEC_PER_MSEC;
-
-+static bool dl_server_stopped(struct sched_dl_entity *dl_se);
-+
- static enum hrtimer_restart dl_server_timer(struct hrtimer *timer, struct sched_dl_entity *dl_se)
- {
- struct rq *rq = rq_of_dl_se(dl_se);
-@@ -1234,6 +1236,7 @@ static enum hrtimer_restart dl_server_timer(struct hrtimer *timer, struct sched_
-
- if (!dl_se->server_has_tasks(dl_se)) {
- replenish_dl_entity(dl_se);
-+ dl_server_stopped(dl_se);
- return HRTIMER_NORESTART;
- }
-
-@@ -1639,8 +1642,10 @@ void dl_server_update_idle_time(struct rq *rq, struct task_struct *p)
- void dl_server_update(struct sched_dl_entity *dl_se, s64 delta_exec)
- {
- /* 0 runtime = fair server disabled */
-- if (dl_se->dl_runtime)
-+ if (dl_se->dl_runtime) {
-+ dl_se->dl_server_idle = 0;
- update_curr_dl_se(dl_se->rq, dl_se, delta_exec);
-+ }
- }
-
- void dl_server_start(struct sched_dl_entity *dl_se)
-@@ -1663,7 +1668,7 @@ void dl_server_start(struct sched_dl_entity *dl_se)
- setup_new_dl_entity(dl_se);
- }
-
-- if (!dl_se->dl_runtime)
-+ if (!dl_se->dl_runtime || dl_se->dl_server_active)
- return;
-
- dl_se->dl_server_active = 1;
-@@ -1684,6 +1689,20 @@ void dl_server_stop(struct sched_dl_entity *dl_se)
- dl_se->dl_server_active = 0;
- }
-
-+static bool dl_server_stopped(struct sched_dl_entity *dl_se)
-+{
-+ if (!dl_se->dl_server_active)
-+ return false;
-+
-+ if (dl_se->dl_server_idle) {
-+ dl_server_stop(dl_se);
-+ return true;
-+ }
-+
-+ dl_se->dl_server_idle = 1;
-+ return false;
-+}
-+
- void dl_server_init(struct sched_dl_entity *dl_se, struct rq *rq,
- dl_server_has_tasks_f has_tasks,
- dl_server_pick_f pick_task)
-@@ -2435,7 +2454,7 @@ static struct task_struct *__pick_task_dl(struct rq *rq)
- if (dl_server(dl_se)) {
- p = dl_se->server_pick_task(dl_se);
- if (!p) {
-- if (dl_server_active(dl_se)) {
-+ if (!dl_server_stopped(dl_se)) {
- dl_se->dl_yielded = 1;
- update_curr_dl_se(rq, dl_se, 0);
- }
-diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
-index 7a14da5396fb..3ab8d4765edd 100644
---- a/kernel/sched/fair.c
-+++ b/kernel/sched/fair.c
-@@ -5889,7 +5889,6 @@ static bool throttle_cfs_rq(struct cfs_rq *cfs_rq)
- struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg);
- struct sched_entity *se;
- long queued_delta, runnable_delta, idle_delta, dequeue = 1;
-- long rq_h_nr_queued = rq->cfs.h_nr_queued;
-
- raw_spin_lock(&cfs_b->lock);
- /* This will start the period timer if necessary */
-@@ -5973,10 +5972,6 @@ static bool throttle_cfs_rq(struct cfs_rq *cfs_rq)
-
- /* At this point se is NULL and we are at root level*/
- sub_nr_running(rq, queued_delta);
--
-- /* Stop the fair server if throttling resulted in no runnable tasks */
-- if (rq_h_nr_queued && !rq->cfs.h_nr_queued)
-- dl_server_stop(&rq->fair_server);
- done:
- /*
- * Note: distribution will already see us throttled via the
-@@ -7070,7 +7065,6 @@ static void set_next_buddy(struct sched_entity *se);
- static int dequeue_entities(struct rq *rq, struct sched_entity *se, int flags)
- {
- bool was_sched_idle = sched_idle_rq(rq);
-- int rq_h_nr_queued = rq->cfs.h_nr_queued;
- bool task_sleep = flags & DEQUEUE_SLEEP;
- bool task_delayed = flags & DEQUEUE_DELAYED;
- struct task_struct *p = NULL;
-@@ -7154,9 +7148,6 @@ static int dequeue_entities(struct rq *rq, struct sched_entity *se, int flags)
-
- sub_nr_running(rq, h_nr_queued);
-
-- if (rq_h_nr_queued && !rq->cfs.h_nr_queued)
-- dl_server_stop(&rq->fair_server);
--
- /* balance early to pull high priority tasks */
- if (unlikely(!was_sched_idle && sched_idle_rq(rq)))
- rq->next_balance = jiffies;
---
-2.39.5
-
Link: https://lore.kernel.org/r/20250627115118.438797-3-juri.lelli@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
- kernel/sched/deadline.c | 7 +++++++
+ kernel/sched/deadline.c | 7 +++++++
1 file changed, 7 insertions(+)
-diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
-index ef5b5c045769..135580a41e14 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
-@@ -3007,7 +3007,14 @@ void dl_clear_root_domain(struct root_domain *rd)
+@@ -2976,7 +2976,14 @@ void dl_clear_root_domain(struct root_do
int i;
guard(raw_spinlock_irqsave)(&rd->dl_bw.lock);
/*
* dl_servers are not tasks. Since dl_add_task_root_domain ignores
---
-2.39.5
-
drm-rockchip-vop2-fail-cleanly-if-missing-a-primary-.patch
drm-rockchip-vop2-fix-the-update-of-layer-port-selec.patch
sched-psi-optimize-psi_group_change-cpu_clock-usage.patch
-sched-deadline-less-agressive-dl_server-handling.patch
fbcon-fix-outdated-registered_fb-reference-in-commen.patch
netfilter-nf_tables-drop-dead-code-from-fill_-_info-.patch
netfilter-nf_tables-adjust-lockdep-assertions-handli.patch
net_sched-act_ctinfo-use-atomic64_t-for-three-counte.patch
rdma-mlx5-fix-umr-modifying-of-mkey-page-size.patch
xen-fix-uaf-in-dmabuf_exp_from_pages.patch
-sched-deadline-initialize-dl_servers-after-smp.patch
sched-deadline-reset-extra_bw-to-max_bw-when-clearin.patch
iommu-vt-d-do-not-wipe-out-the-page-table-nid-when-d.patch
iommu-vt-d-fix-missing-pasid-in-dev-tlb-flush-with-c.patch
projects / thirdparty / kernel / stable-queue.git / commitdiff
