This is a note to let you know that I've just added the patch titled
sched/fair: Take the scheduling domain into account in select_idle_core()
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
sched-fair-take-the-scheduling-domain-into-account-i.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit cd95ee4a01095d18f5989af39f5351ec95a9ebdb
Author: Keisuke Nishimura <keisuke.nishimura@xxxxxxxx>
Date: Wed Jan 10 14:17:07 2024 +0100
sched/fair: Take the scheduling domain into account in select_idle_core()
[ Upstream commit 23d04d8c6b8ec339057264659b7834027f3e6a63 ]
When picking a CPU on task wakeup, select_idle_core() has to take
into account the scheduling domain where the function looks for the CPU.
This is because the "isolcpus" kernel command line option can remove CPUs
from the domain to isolate them from other SMT siblings.
This change replaces the set of CPUs allowed to run the task from
p->cpus_ptr by the intersection of p->cpus_ptr and sched_domain_span(sd)
which is stored in the 'cpus' argument provided by select_idle_cpu().
Fixes: 9fe1f127b913 ("sched/fair: Merge select_idle_core/cpu()")
Signed-off-by: Keisuke Nishimura <keisuke.nishimura@xxxxxxxx>
Signed-off-by: Julia Lawall <julia.lawall@xxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240110131707.437301-2-keisuke.nishimura@xxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 1c4e54fffb8b6..91c101ecfef9f 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6656,7 +6656,7 @@ static int select_idle_core(struct task_struct *p, int core, struct cpumask *cpu
if (!available_idle_cpu(cpu)) {
idle = false;
if (*idle_cpu == -1) {
- if (sched_idle_cpu(cpu) && cpumask_test_cpu(cpu, p->cpus_ptr)) {
+ if (sched_idle_cpu(cpu) && cpumask_test_cpu(cpu, cpus)) {
*idle_cpu = cpu;
break;
}
@@ -6664,7 +6664,7 @@ static int select_idle_core(struct task_struct *p, int core, struct cpumask *cpu
}
break;
}
- if (*idle_cpu == -1 && cpumask_test_cpu(cpu, p->cpus_ptr))
+ if (*idle_cpu == -1 && cpumask_test_cpu(cpu, cpus))
*idle_cpu = cpu;
}
