From: Connor O'Brien <connoro@google.com>
Switch logic that deactivates, sets the task cpu,
and reactivates a task on a different rq to use a
helper that will be later extended to push entire
blocked task chains.
This patch was broken out from a larger chain migration
patch originally by Connor O'Brien.
Cc: Joel Fernandes <joelaf@google.com>
Cc: Qais Yousef <qyousef@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Zimuzo Ezeozue <zezeozue@google.com>
Cc: Youssef Esmat <youssefesmat@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Metin Kaya <Metin.Kaya@arm.com>
Cc: Xuewen Yan <xuewen.yan94@gmail.com>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-team@android.com
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Connor O'Brien <connoro@google.com>
[jstultz: split out from larger chain migration patch]
Signed-off-by: John Stultz <jstultz@google.com>
---
v8:
* Renamed from push_task_chain to do_push_task so it makes
more sense without proxy-execution
---
kernel/sched/core.c | 4 +---
kernel/sched/deadline.c | 8 ++------
kernel/sched/rt.c | 8 ++------
kernel/sched/sched.h | 9 +++++++++
4 files changed, 14 insertions(+), 15 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 7019a40457a6..586a3f8186bd 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2712,9 +2712,7 @@ int push_cpu_stop(void *arg)
// XXX validate p is still the highest prio task
if (task_rq(p) == rq) {
- deactivate_task(rq, p, 0);
- set_task_cpu(p, lowest_rq->cpu);
- activate_task(lowest_rq, p, 0);
+ do_push_task(rq, lowest_rq, p);
resched_curr(lowest_rq);
}
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index a04a436af8cc..e68d88963e89 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -2443,9 +2443,7 @@ static int push_dl_task(struct rq *rq)
goto retry;
}
- deactivate_task(rq, next_task, 0);
- set_task_cpu(next_task, later_rq->cpu);
- activate_task(later_rq, next_task, 0);
+ do_push_task(rq, later_rq, next_task);
ret = 1;
resched_curr(later_rq);
@@ -2531,9 +2529,7 @@ static void pull_dl_task(struct rq *this_rq)
if (is_migration_disabled(p)) {
push_task = get_push_task(src_rq);
} else {
- deactivate_task(src_rq, p, 0);
- set_task_cpu(p, this_cpu);
- activate_task(this_rq, p, 0);
+ do_push_task(src_rq, this_rq, p);
dmin = p->dl.deadline;
resched = true;
}
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 3261b067b67e..dd072d11cc02 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -2106,9 +2106,7 @@ static int push_rt_task(struct rq *rq, bool pull)
goto retry;
}
- deactivate_task(rq, next_task, 0);
- set_task_cpu(next_task, lowest_rq->cpu);
- activate_task(lowest_rq, next_task, 0);
+ do_push_task(rq, lowest_rq, next_task);
resched_curr(lowest_rq);
ret = 1;
@@ -2379,9 +2377,7 @@ static void pull_rt_task(struct rq *this_rq)
if (is_migration_disabled(p)) {
push_task = get_push_task(src_rq);
} else {
- deactivate_task(src_rq, p, 0);
- set_task_cpu(p, this_cpu);
- activate_task(this_rq, p, 0);
+ do_push_task(src_rq, this_rq, p);
resched = true;
}
/*
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index d2242679239e..16057de24ecd 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -3472,5 +3472,14 @@ static inline void init_sched_mm_cid(struct task_struct *t) { }
extern u64 avg_vruntime(struct cfs_rq *cfs_rq);
extern int entity_eligible(struct cfs_rq *cfs_rq, struct sched_entity *se);
+#ifdef CONFIG_SMP
+static inline
+void do_push_task(struct rq *rq, struct rq *dst_rq, struct task_struct *task)
+{
+ deactivate_task(rq, task, 0);
+ set_task_cpu(task, dst_rq->cpu);
+ activate_task(dst_rq, task, 0);
+}
+#endif
#endif /* _KERNEL_SCHED_SCHED_H */
--
2.44.0.478.gd926399ef9-googOn 01/04/24 16:44, John Stultz wrote:
> From: Connor O'Brien <connoro@google.com>
>
> Switch logic that deactivates, sets the task cpu,
> and reactivates a task on a different rq to use a
> helper that will be later extended to push entire
> blocked task chains.
>
> This patch was broken out from a larger chain migration
> patch originally by Connor O'Brien.
>
> Cc: Joel Fernandes <joelaf@google.com>
> Cc: Qais Yousef <qyousef@google.com>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Juri Lelli <juri.lelli@redhat.com>
> Cc: Vincent Guittot <vincent.guittot@linaro.org>
> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
> Cc: Valentin Schneider <vschneid@redhat.com>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: Ben Segall <bsegall@google.com>
> Cc: Zimuzo Ezeozue <zezeozue@google.com>
> Cc: Youssef Esmat <youssefesmat@google.com>
> Cc: Mel Gorman <mgorman@suse.de>
> Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: Waiman Long <longman@redhat.com>
> Cc: Boqun Feng <boqun.feng@gmail.com>
> Cc: "Paul E. McKenney" <paulmck@kernel.org>
> Cc: Metin Kaya <Metin.Kaya@arm.com>
> Cc: Xuewen Yan <xuewen.yan94@gmail.com>
> Cc: K Prateek Nayak <kprateek.nayak@amd.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: kernel-team@android.com
> Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Naming nit below notwithstanding:
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
> Signed-off-by: Connor O'Brien <connoro@google.com>
> [jstultz: split out from larger chain migration patch]
> Signed-off-by: John Stultz <jstultz@google.com>
> diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
> index d2242679239e..16057de24ecd 100644
> --- a/kernel/sched/sched.h
> +++ b/kernel/sched/sched.h
> @@ -3472,5 +3472,14 @@ static inline void init_sched_mm_cid(struct task_struct *t) { }
>
> extern u64 avg_vruntime(struct cfs_rq *cfs_rq);
> extern int entity_eligible(struct cfs_rq *cfs_rq, struct sched_entity *se);
> +#ifdef CONFIG_SMP
> +static inline
> +void do_push_task(struct rq *rq, struct rq *dst_rq, struct task_struct *task)
The naming IMO unfortunately clashes with the hotplug push_task /
balance_push() stuff.
AFAICT this is move_queued_task() but in a double rq lock
context. How about move_queued_task_locked()?
Interestingly, all the patched call sites end up with a resched_curr(), but
move_queued_task() has wakeup_preempt() instead.
> +{
> + deactivate_task(rq, task, 0);
> + set_task_cpu(task, dst_rq->cpu);
> + activate_task(dst_rq, task, 0);
> +}
> +#endif
>
> #endif /* _KERNEL_SCHED_SCHED_H */
> --
> 2.44.0.478.gd926399ef9-goog
On Tue, Apr 9, 2024 at 9:30 AM Valentin Schneider <vschneid@redhat.com> wrote: > Naming nit below notwithstanding: > > Reviewed-by: Valentin Schneider <vschneid@redhat.com> Hey! Thanks so much for taking a look and providing this feedback! I really appreciate it! > > +static inline > > +void do_push_task(struct rq *rq, struct rq *dst_rq, struct task_struct *task) > > The naming IMO unfortunately clashes with the hotplug push_task / > balance_push() stuff. > > AFAICT this is move_queued_task() but in a double rq lock > context. How about move_queued_task_locked()? Sounds good to me! Changed in my pre-v10 tree. > Interestingly, all the patched call sites end up with a resched_curr(), but > move_queued_task() has wakeup_preempt() instead. Yeah. I'll look a bit more to see if I can find a way to fold the resched in as well, and try to make sure I understand the subtle difference in move_queued_task() - I don't want the name similarity to confuse if the behavior is different. Again, thanks so much for the feedback and review! -john
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