This is a note to let you know that I've just added the patch titled
sched/uclamp: Make select_idle_capacity() use util_fits_cpu()
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-uclamp-make-select_idle_capacity-use-util_fits.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 5b1e6b7aa375c043c63e61516d23e77c0a68155b
Author: Qais Yousef <qais.yousef@xxxxxxx>
Date: Thu Aug 4 15:36:04 2022 +0100
sched/uclamp: Make select_idle_capacity() use util_fits_cpu()
[ Upstream commit b759caa1d9f667b94727b2ad12589cbc4ce13a82 ]
Use the new util_fits_cpu() to ensure migration margin and capacity
pressure are taken into account correctly when uclamp is being used
otherwise we will fail to consider CPUs as fitting in scenarios where
they should.
Fixes: b4c9c9f15649 ("sched/fair: Prefer prev cpu in asymmetric wakeup path")
Signed-off-by: Qais Yousef <qais.yousef@xxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220804143609.515789-5-qais.yousef@xxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index c8eb5ff81084..c877bbfe5deb 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6779,21 +6779,23 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool
static int
select_idle_capacity(struct task_struct *p, struct sched_domain *sd, int target)
{
- unsigned long task_util, best_cap = 0;
+ unsigned long task_util, util_min, util_max, best_cap = 0;
int cpu, best_cpu = -1;
struct cpumask *cpus;
cpus = this_cpu_cpumask_var_ptr(select_rq_mask);
cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr);
- task_util = uclamp_task_util(p);
+ task_util = task_util_est(p);
+ util_min = uclamp_eff_value(p, UCLAMP_MIN);
+ util_max = uclamp_eff_value(p, UCLAMP_MAX);
for_each_cpu_wrap(cpu, cpus, target) {
unsigned long cpu_cap = capacity_of(cpu);
if (!available_idle_cpu(cpu) && !sched_idle_cpu(cpu))
continue;
- if (fits_capacity(task_util, cpu_cap))
+ if (util_fits_cpu(task_util, util_min, util_max, cpu))
return cpu;
if (cpu_cap > best_cap) {
