[PATCH v12 5/7] sched: Consolidate pick_*_task to task_is_pushable helper

John Stultz
2024-08-13T23:57:52Z

From: Connor O'Brien <connoro@google.com>

This patch consolidates rt and deadline pick_*_task functions to
a task_is_pushable() helper

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@layalina.io>
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: Mel Gorman <mgorman@suse.de>
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: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: kernel-team@android.com
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Tested-by: Metin Kaya <metin.kaya@arm.com>
Reviewed-by: Metin Kaya <metin.kaya@arm.com>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Connor O'Brien <connoro@google.com>
[jstultz: split out from larger chain migration patch,
renamed helper function]
Signed-off-by: John Stultz <jstultz@google.com>
---
v7:
* Split from chain migration patch
* Renamed function
v11:
* Switched to bool (though later in the series it goes
to a tri-state return) for now to simplify review.
Will add tri-state handling later in the series when
its needed. Suggested by Metin and others.
---
kernel/sched/deadline.c | 10 +---------
kernel/sched/rt.c | 11 +----------
kernel/sched/sched.h | 10 ++++++++++
3 files changed, 12 insertions(+), 19 deletions(-)

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index ac60d2819bd1d..d3050f6c2958d 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -2183,14 +2183,6 @@ static void task_fork_dl(struct task_struct *p)
/* Only try algorithms three times */
#define DL_MAX_TRIES 3

-static int pick_dl_task(struct rq *rq, struct task_struct *p, int cpu)
-{
- if (!task_on_cpu(rq, p) &&
- cpumask_test_cpu(cpu, &p->cpus_mask))
- return 1;
- return 0;
-}
-
/*
* Return the earliest pushable rq's task, which is suitable to be executed
* on the CPU, NULL otherwise:
@@ -2209,7 +2201,7 @@ static struct task_struct *pick_earliest_pushable_dl_task(struct rq *rq, int cpu
if (next_node) {
p = __node_2_pdl(next_node);

- if (pick_dl_task(rq, p, cpu))
+ if (task_is_pushable(rq, p, cpu))
return p;

next_node = rb_next(next_node);
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 496d3e6ab57d2..9f07f09641f7a 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1790,15 +1790,6 @@ static void put_prev_task_rt(struct rq *rq, struct task_struct *p)
/* Only try algorithms three times */
#define RT_MAX_TRIES 3

-static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu)
-{
- if (!task_on_cpu(rq, p) &&
- cpumask_test_cpu(cpu, &p->cpus_mask))
- return 1;
-
- return 0;
-}
-
/*
* Return the highest pushable rq's task, which is suitable to be executed
* on the CPU, NULL otherwise
@@ -1812,7 +1803,7 @@ static struct task_struct *pick_highest_pushable_task(struct rq *rq, int cpu)
return NULL;

plist_for_each_entry(p, head, pushable_tasks) {
- if (pick_rt_task(rq, p, cpu))
+ if (task_is_pushable(rq, p, cpu))
return p;
}

diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index d2cc31c2457e5..10ef612c078f9 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -3586,6 +3586,16 @@ void move_queued_task_locked(struct rq *src_rq, struct rq *dst_rq, struct task_s
set_task_cpu(task, dst_rq->cpu);
activate_task(dst_rq, task, 0);
}
+
+static inline
+bool task_is_pushable(struct rq *rq, struct task_struct *p, int cpu)
+{
+ if (!task_on_cpu(rq, p) &&
+ cpumask_test_cpu(cpu, &p->cpus_mask))
+ return true;
+
+ return false;
+}
#endif

#ifdef CONFIG_RT_MUTEXES
--
2.46.0.76.ge559c4bf1a-goog