From: Andrea Righi <arighi@nvidia.com>
To: Tejun Heo <tj@kernel.org>, David Vernet <void@manifault.com>,
Changwoo Min <changwoo@igalia.com>,
John Stultz <jstultz@google.com>
Cc: Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
Valentin Schneider <vschneid@redhat.com>,
K Prateek Nayak <kprateek.nayak@amd.com>,
Christian Loehle <christian.loehle@arm.com>,
David Dai <david.dai@linux.dev>, Emil Tsalapatis <etsal@meta.com>,
Lee Trager <ltrager@nvidia.com>,
Richard Cheng <icheng@nvidia.com>, Koba Ko <kobak@nvidia.com>,
Aiqun Yu <aiqun.yu@oss.qualcomm.com>,
sched-ext@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: [PATCH 05/18] sched: Pass next class to sched_change_begin()
Date: Mon, 31 Aug 2026 15:42:15 +0200 [thread overview]
Message-ID: <20260831134338.1531664-6-arighi@nvidia.com> (raw)
In-Reply-To: <20260831134338.1531664-1-arighi@nvidia.com>
sched_change_begin() currently only receives the task whose scheduling
state is being changed. It cannot distinguish a class transition from a
same-class update before recording the task queueing state.
Pass the incoming scheduling class to sched_change_begin() and update all
callers. This allows transition handling to run before the normal dequeue
and class change.
This is a preparatory change to support proxy execution with sched_ext.
Signed-off-by: Andrea Righi <arighi@nvidia.com>
---
kernel/sched/core.c | 12 +++++++-----
kernel/sched/ext/ext.c | 7 ++++---
kernel/sched/ext/sub.c | 9 ++++++---
kernel/sched/sched.h | 9 ++++++---
kernel/sched/syscalls.c | 4 ++--
5 files changed, 25 insertions(+), 16 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 0a2eabadfee02..26b8da8c8a2c5 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2802,7 +2802,7 @@ void set_cpus_allowed_common(struct task_struct *p, struct affinity_context *ctx
static void
do_set_cpus_allowed(struct task_struct *p, struct affinity_context *ctx)
{
- scoped_guard (sched_change, p, DEQUEUE_SAVE)
+ scoped_guard (sched_change, p, p->sched_class, DEQUEUE_SAVE)
p->sched_class->set_cpus_allowed(p, ctx);
}
@@ -7753,7 +7753,7 @@ void rt_mutex_setprio(struct task_struct *p, struct task_struct *pi_task)
if (prev_class != next_class)
queue_flag |= DEQUEUE_CLASS;
- scoped_guard (sched_change, p, queue_flag) {
+ scoped_guard (sched_change, p, next_class, queue_flag) {
/*
* Boosting condition are:
* 1. -rt task is running and holds mutex A
@@ -8430,7 +8430,7 @@ int migrate_task_to(struct task_struct *p, int target_cpu)
void sched_setnuma(struct task_struct *p, int nid)
{
guard(task_rq_lock)(p);
- scoped_guard (sched_change, p, DEQUEUE_SAVE)
+ scoped_guard (sched_change, p, p->sched_class, DEQUEUE_SAVE)
p->numa_preferred_nid = nid;
}
#endif /* CONFIG_NUMA_BALANCING */
@@ -9548,7 +9548,7 @@ void sched_move_task(struct task_struct *tsk, bool for_autogroup)
CLASS(task_rq_lock, rq_guard)(tsk);
rq = rq_guard.rq;
- scoped_guard (sched_change, tsk, queue_flags) {
+ scoped_guard (sched_change, tsk, tsk->sched_class, queue_flags) {
sched_change_group(tsk);
if (!for_autogroup)
scx_cgroup_move_task(tsk);
@@ -11252,7 +11252,9 @@ static inline void sched_mm_cid_fork(struct task_struct *t) { }
static DEFINE_PER_CPU(struct sched_change_ctx, sched_change_ctx);
-struct sched_change_ctx *sched_change_begin(struct task_struct *p, unsigned int flags)
+struct sched_change_ctx *
+sched_change_begin(struct task_struct *p, const struct sched_class *next_class,
+ unsigned int flags)
{
struct sched_change_ctx *ctx = this_cpu_ptr(&sched_change_ctx);
struct rq *rq = task_rq(p);
diff --git a/kernel/sched/ext/ext.c b/kernel/sched/ext/ext.c
index 10af28a9f2c0c..00c368e2fc82d 100644
--- a/kernel/sched/ext/ext.c
+++ b/kernel/sched/ext/ext.c
@@ -6159,7 +6159,8 @@ void scx_bypass(struct scx_sched *sch, bool bypass)
scx_task_slice_ended(rq, p);
/* cycling deq/enq is enough, see the function comment */
- scoped_guard (sched_change, p, DEQUEUE_SAVE | DEQUEUE_MOVE) {
+ scoped_guard (sched_change, p, p->sched_class,
+ DEQUEUE_SAVE | DEQUEUE_MOVE) {
/* nothing */ ;
}
}
@@ -6441,7 +6442,7 @@ static void scx_root_disable(struct scx_sched *sch)
if (old_class != new_class)
queue_flags |= DEQUEUE_CLASS;
- scoped_guard (sched_change, p, queue_flags) {
+ scoped_guard (sched_change, p, new_class, queue_flags) {
p->sched_class = new_class;
}
@@ -7802,7 +7803,7 @@ static void scx_root_enable_workfn(struct kthread_work *work)
if (old_class != new_class)
queue_flags |= DEQUEUE_CLASS;
- scoped_guard (sched_change, p, queue_flags) {
+ scoped_guard (sched_change, p, new_class, queue_flags) {
scx_set_task_slice(p, READ_ONCE(sch->slice_dfl));
p->sched_class = new_class;
}
diff --git a/kernel/sched/ext/sub.c b/kernel/sched/ext/sub.c
index 0554448835bd0..c3955c8163a03 100644
--- a/kernel/sched/ext/sub.c
+++ b/kernel/sched/ext/sub.c
@@ -1255,7 +1255,8 @@ static void scx_rehome_task(struct scx_sched *to, struct task_struct *p)
lockdep_assert_held(&p->pi_lock);
lockdep_assert_rq_held(task_rq(p));
- scoped_guard (sched_change, p, DEQUEUE_SAVE | DEQUEUE_MOVE) {
+ scoped_guard (sched_change, p, p->sched_class,
+ DEQUEUE_SAVE | DEQUEUE_MOVE) {
scx_disable_and_exit_task(scx_task_sched(p), p);
scx_set_task_state(p, SCX_TASK_INIT_BEGIN);
scx_set_task_state(p, SCX_TASK_INIT);
@@ -1285,7 +1286,8 @@ static void scx_punt_task(struct scx_sched *to, struct task_struct *p)
lockdep_assert_rq_held(task_rq(p));
WARN_ON_ONCE(!READ_ONCE(to->bypass_depth));
- scoped_guard (sched_change, p, DEQUEUE_SAVE | DEQUEUE_MOVE) {
+ scoped_guard (sched_change, p, p->sched_class,
+ DEQUEUE_SAVE | DEQUEUE_MOVE) {
scx_disable_and_exit_task(scx_task_sched(p), p);
scx_set_task_sched(p, to);
}
@@ -1939,7 +1941,8 @@ void scx_sub_enable_workfn(struct kthread_work *work)
if (!(p->scx.flags & SCX_TASK_SUB_INIT))
continue;
- scoped_guard (sched_change, p, DEQUEUE_SAVE | DEQUEUE_MOVE) {
+ scoped_guard (sched_change, p, p->sched_class,
+ DEQUEUE_SAVE | DEQUEUE_MOVE) {
/*
* $p must be either READY or ENABLED. If ENABLED,
* __scx_disabled_and_exit_task() first disables and
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index e656c7059bf86..6bba1f3b5d4cd 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -4240,13 +4240,16 @@ struct sched_change_ctx {
bool running;
};
-struct sched_change_ctx *sched_change_begin(struct task_struct *p, unsigned int flags);
+struct sched_change_ctx *
+sched_change_begin(struct task_struct *p, const struct sched_class *next_class,
+ unsigned int flags);
void sched_change_end(struct sched_change_ctx *ctx);
DEFINE_CLASS(sched_change, struct sched_change_ctx *,
sched_change_end(_T),
- sched_change_begin(p, flags),
- struct task_struct *p, unsigned int flags)
+ sched_change_begin(p, next_class, flags),
+ struct task_struct *p, const struct sched_class *next_class,
+ unsigned int flags)
DEFINE_CLASS_IS_UNCONDITIONAL(sched_change)
diff --git a/kernel/sched/syscalls.c b/kernel/sched/syscalls.c
index b215b0ead9a60..bc32ce76ff4fe 100644
--- a/kernel/sched/syscalls.c
+++ b/kernel/sched/syscalls.c
@@ -85,7 +85,7 @@ void set_user_nice(struct task_struct *p, long nice)
return;
}
- scoped_guard (sched_change, p, DEQUEUE_SAVE) {
+ scoped_guard (sched_change, p, p->sched_class, DEQUEUE_SAVE) {
p->static_prio = NICE_TO_PRIO(nice);
set_load_weight(p, true);
old_prio = p->prio;
@@ -678,7 +678,7 @@ int __sched_setscheduler(struct task_struct *p,
if (prev_class != next_class)
queue_flags |= DEQUEUE_CLASS;
- scoped_guard (sched_change, p, queue_flags) {
+ scoped_guard (sched_change, p, next_class, queue_flags) {
if (!(attr->sched_flags & SCHED_FLAG_KEEP_PARAMS)) {
__setscheduler_params(p, attr);
--
2.55.0
next prev parent reply other threads:[~2026-08-31 13:44 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-31 13:42 [PATCHSET v13 sched_ext/for-7.4] sched: Make proxy execution compatible with sched_ext Andrea Righi
2026-08-31 13:42 ` [PATCH 01/18] sched/core: Drop mutex locks before proxy rescheduling Andrea Righi
2026-08-31 13:42 ` [PATCH 02/18] sched/core: Dequeue waking proxy donors before reset Andrea Righi
2026-09-01 5:24 ` K Prateek Nayak
2026-08-31 13:42 ` [PATCH 03/18] sched: Make NOHZ CFS bandwidth checks follow proxy donor Andrea Righi
2026-08-31 13:42 ` [PATCH 04/18] sched/core: Avoid false migration warning for proxy donors Andrea Righi
2026-08-31 13:42 ` Andrea Righi [this message]
2026-08-31 13:42 ` [PATCH 06/18] sched: Add helper to block retained " Andrea Righi
2026-08-31 13:42 ` [PATCH 07/18] sched: Add sched_ext hooks for proxy execution Andrea Righi
2026-08-31 13:42 ` [PATCH 08/18] sched: Introduce WF_ON_RQ wake flag Andrea Righi
2026-08-31 13:42 ` [PATCH 09/18] sched_ext: Block proxy donors across scheduler transitions Andrea Righi
2026-08-31 13:42 ` [PATCH 10/18] sched_ext: Fix ops.running/stopping() pairing for proxy-exec donors Andrea Righi
2026-08-31 13:42 ` [PATCH 11/18] sched_ext: Move reject DSQ draining into core Andrea Righi
2026-08-31 13:42 ` [PATCH 12/18] sched_ext: Generalize the reject DSQ reenqueue path Andrea Righi
2026-09-03 22:39 ` Tejun Heo
2026-08-31 13:42 ` [PATCH 13/18] sched_ext: Handle proxy-exec races in remote DSQ transfers Andrea Righi
2026-08-31 13:42 ` [PATCH 14/18] sched_ext: Split curr|donor references properly Andrea Righi
2026-08-31 13:42 ` [PATCH 15/18] sched_ext: Delegate proxy donor admission to BPF schedulers Andrea Righi
2026-08-31 13:42 ` [PATCH 16/18] sched_ext: Add selftest for blocked donor admission Andrea Righi
2026-08-31 13:42 ` [PATCH 17/18] sched_ext: scx_qmap: Add proxy execution support Andrea Righi
2026-09-01 7:52 ` Richard Cheng
2026-08-31 13:42 ` [PATCH 18/18] sched: Allow enabling proxy exec with sched_ext Andrea Righi
2026-09-03 22:51 ` [PATCHSET v13 sched_ext/for-7.4] sched: Make proxy execution compatible " Tejun Heo
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