android/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

sched/fair: Fixes for capacity inversion detection

Browse Source 
commit da07d2f9c153e457e845d4dcfdd13568d71d18a4 upstream.

Traversing the Perf Domains requires rcu_read_lock() to be held and is
conditional on sched_energy_enabled(). Ensure right protections applied.

Also skip capacity inversion detection for our own pd; which was an
error.

Fixes: 44c7b80bffc3 ("sched/fair: Detect capacity inversion")
Reported-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Qais Yousef (Google) <qyousef@layalina.io>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20230112122708.330667-3-qyousef@layalina.io
(cherry picked from commit da07d2f9c153e457e845d4dcfdd13568d71d18a4)
Signed-off-by: Qais Yousef (Google) <qyousef@layalina.io>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Qais Yousef 2023-04-18 15:09:43 +01:00 committed by Greg Kroah-Hartman
parent 89ad8a672f
commit 4735b6f74f
1 changed files with 11 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
kernel/sched/fair.c
View File

@ -8407,16 +8407,23 @@ static void update_cpu_capacity(struct sched_domain *sd, int cpu)
* * Thermal pressure will impact all cpus in this perf domain
* equally.
*/
if (static_branch_unlikely(&sched_asym_cpucapacity)) {
if (sched_energy_enabled()) {
unsigned long inv_cap = capacity_orig - thermal_load_avg(rq);
struct perf_domain *pd = rcu_dereference(rq->rd->pd);
struct perf_domain *pd;
rcu_read_lock();
pd = rcu_dereference(rq->rd->pd);
rq->cpu_capacity_inverted = 0;
for (; pd; pd = pd->next) {
struct cpumask *pd_span = perf_domain_span(pd);
unsigned long pd_cap_orig, pd_cap;
/* We can't be inverted against our own pd */
if (cpumask_test_cpu(cpu_of(rq), pd_span))
continue;
cpu = cpumask_any(pd_span);
pd_cap_orig = arch_scale_cpu_capacity(cpu);
@ -8441,6 +8448,8 @@ static void update_cpu_capacity(struct sched_domain *sd, int cpu)
break;
}
}
rcu_read_unlock();
}
trace_sched_cpu_capacity_tp(rq);