From: Shrikanth Hegde <sshegde@linux.ibm.com>
To: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com,
vincent.guittot@linaro.org, tglx@linutronix.de,
yury.norov@gmail.com, maddy@linux.ibm.com
Cc: sshegde@linux.ibm.com, vschneid@redhat.com,
dietmar.eggemann@arm.com, rostedt@goodmis.org,
kprateek.nayak@amd.com, huschle@linux.ibm.com,
srikar@linux.ibm.com, linux-kernel@vger.kernel.org,
christophe.leroy@csgroup.eu, linuxppc-dev@lists.ozlabs.org,
gregkh@linuxfoundation.org
Subject: [RFC v2 5/9] sched/rt: Don't select CPU marked as avoid for wakeup and push/pull rt task
Date: Thu, 26 Jun 2025 00:41:04 +0530 [thread overview]
Message-ID: <20250625191108.1646208-6-sshegde@linux.ibm.com> (raw)
In-Reply-To: <20250625191108.1646208-1-sshegde@linux.ibm.com>
- While wakeup don't select the CPU if it marked as avoid.
- Don't pull a task if CPU is marked as avoid.
- Don't push a task to a CPU marked as Avoid.
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
---
kernel/sched/rt.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 15d5855c542c..fd9df6f46135 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1549,6 +1549,8 @@ select_task_rq_rt(struct task_struct *p, int cpu, int flags)
if (!test && target != -1 && !rt_task_fits_capacity(p, target))
goto out_unlock;
+ if (cpu_avoid(target))
+ goto out_unlock;
/*
* Don't bother moving it if the destination CPU is
* not running a lower priority task.
@@ -1871,7 +1873,7 @@ static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq)
for (tries = 0; tries < RT_MAX_TRIES; tries++) {
cpu = find_lowest_rq(task);
- if ((cpu == -1) || (cpu == rq->cpu))
+ if ((cpu == -1) || (cpu == rq->cpu) || cpu_avoid(cpu))
break;
lowest_rq = cpu_rq(cpu);
@@ -1969,7 +1971,7 @@ static int push_rt_task(struct rq *rq, bool pull)
return 0;
cpu = find_lowest_rq(rq->curr);
- if (cpu == -1 || cpu == rq->cpu)
+ if (cpu == -1 || cpu == rq->cpu || cpu_avoid(cpu))
return 0;
/*
@@ -2232,6 +2234,9 @@ static void pull_rt_task(struct rq *this_rq)
if (likely(!rt_overload_count))
return;
+ if (cpu_avoid(this_rq->cpu))
+ return;
+
/*
* Match the barrier from rt_set_overloaded; this guarantees that if we
* see overloaded we must also see the rto_mask bit.
--
2.43.0
next prev parent reply other threads:[~2025-06-25 19:12 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-25 19:10 [RFC v2 0/9] cpu avoid state and push task mechanism Shrikanth Hegde
2025-06-25 19:11 ` [RFC v2 1/9] sched/docs: Document avoid_cpu_mask and avoid CPU concept Shrikanth Hegde
2025-06-26 6:27 ` Hillf Danton
2025-06-26 14:46 ` Shrikanth Hegde
2025-06-27 0:27 ` Hillf Danton
2025-06-27 4:37 ` Shrikanth Hegde
2025-06-28 22:02 ` Hillf Danton
2025-06-25 19:11 ` [RFC v2 2/9] cpumask: Introduce cpu_avoid_mask Shrikanth Hegde
2025-06-25 19:11 ` [RFC v2 3/9] sched/core: Dont allow to use CPU marked as avoid Shrikanth Hegde
2025-06-25 19:11 ` [RFC v2 4/9] sched/fair: Don't use CPU marked as avoid for wakeup and load balance Shrikanth Hegde
2025-06-26 0:02 ` Yury Norov
2025-06-26 13:42 ` Shrikanth Hegde
2025-06-25 19:11 ` Shrikanth Hegde [this message]
2025-06-25 19:11 ` [RFC v2 6/9] sched/core: Push current task out if CPU is marked as avoid Shrikanth Hegde
2025-08-12 18:40 ` Shrikanth Hegde
2025-06-25 19:11 ` [RFC v2 7/9] sched: Add static key check for cpu_avoid Shrikanth Hegde
2025-06-26 0:12 ` Yury Norov
2025-06-25 19:11 ` [RFC v2 8/9] sysfs: Add cpu_avoid file Shrikanth Hegde
2025-07-01 9:35 ` Greg KH
2025-07-02 6:05 ` Shrikanth Hegde
2025-06-25 19:11 ` [RFC v2 9/9] [DEBUG] powerpc: add debug file for set/unset cpu avoid Shrikanth Hegde
2025-06-25 22:53 ` Yury Norov
2025-06-26 13:39 ` Shrikanth Hegde
2025-06-25 21:55 ` [RFC v2 0/9] cpu avoid state and push task mechanism Yury Norov
2025-06-26 14:33 ` Shrikanth Hegde
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