diff options
| author | Christian Loehle <christian.loehle@arm.com> | 2025-01-20 10:09:46 +0000 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2025-01-23 21:09:25 +0100 |
| commit | 93940fbdc46843cea58708bbe8dd225bd0f32e67 (patch) | |
| tree | 549e756a2a4fd97c673e0b9d6a49f93266b4f70b | |
| parent | 2b16c631832df6cf8782fb1fdc7df8a4f03f4f16 (diff) | |
cpufreq/schedutil: Only bind threads if needed
Remove the unconditional binding of sugov kthreads to the affected CPUs
if the cpufreq driver indicates that updates can happen from any CPU.
This allows userspace to set affinities to either save power (waking up
bigger CPUs on HMP can be expensive) or increasing performance (by
letting the utilized CPUs run without preemption of the sugov kthread).
Signed-off-by: Christian Loehle <christian.loehle@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Vincent Guittot <vincent.guittot@linaro.org>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://patch.msgid.link/5a8deed4-7764-4729-a9d4-9520c25fa7e8@arm.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | kernel/sched/cpufreq_schedutil.c | 6 | ||||
| -rw-r--r-- | kernel/sched/syscalls.c | 7 |
2 files changed, 12 insertions, 1 deletions
diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index a2a29e3fffca..1a19d69b91ed 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -666,7 +666,11 @@ static int sugov_kthread_create(struct sugov_policy *sg_policy) } sg_policy->thread = thread; - kthread_bind_mask(thread, policy->related_cpus); + if (policy->dvfs_possible_from_any_cpu) + set_cpus_allowed_ptr(thread, policy->related_cpus); + else + kthread_bind_mask(thread, policy->related_cpus); + init_irq_work(&sg_policy->irq_work, sugov_irq_work); mutex_init(&sg_policy->work_lock); diff --git a/kernel/sched/syscalls.c b/kernel/sched/syscalls.c index 149e2c8036d3..456d339be98f 100644 --- a/kernel/sched/syscalls.c +++ b/kernel/sched/syscalls.c @@ -1130,6 +1130,13 @@ int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask) return 0; /* + * The special/sugov task isn't part of regular bandwidth/admission + * control so let userspace change affinities. + */ + if (dl_entity_is_special(&p->dl)) + return 0; + + /* * Since bandwidth control happens on root_domain basis, * if admission test is enabled, we only admit -deadline * tasks allowed to run on all the CPUs in the task's |