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| author |   Linus Torvalds <torvalds@linux-foundation.org> | 2019-12-19 08:09:43 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-12-19 08:09:43 -0800 |
| commit | 5f096c0ecd53263a94124bdfa516a29f154e44ed (patch) | |
| tree | 8969018030a180083bee488d9cfbaf658fab2822 /kernel | |
| parent | Merge tag 'tpmdd-next-20191219' of git://git.infradead.org/users/jjs/linux-tpmdd (diff) | |
| parent | Merge branch 'pm-cpufreq' (diff) | |
| download | linux-dev-5f096c0ecd53263a94124bdfa516a29f154e44ed.tar.xz linux-dev-5f096c0ecd53263a94124bdfa516a29f154e44ed.zip | |
Merge tag 'pm-5.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fix from Rafael Wysocki:
"Fix a problem related to CPU offline/online and cpufreq governors that
in some system configurations may lead to a system-wide deadlock
during CPU online"
* tag 'pm-5.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpufreq: Avoid leaving stale IRQ work items during CPU offline
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/cpufreq.c | 18 | ||||
| -rw-r--r-- | kernel/sched/cpufreq_schedutil.c | 8 |
2 files changed, 21 insertions, 5 deletions
diff --git a/kernel/sched/cpufreq.c b/kernel/sched/cpufreq.c index b5dcd1d83c7f..7c2fe50fd76d 100644 --- a/kernel/sched/cpufreq.c +++ b/kernel/sched/cpufreq.c @@ -5,6 +5,8 @@ * Copyright (C) 2016, Intel Corporation * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com> */ +#include <linux/cpufreq.h> + #include "sched.h" DEFINE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data); @@ -57,3 +59,19 @@ void cpufreq_remove_update_util_hook(int cpu) rcu_assign_pointer(per_cpu(cpufreq_update_util_data, cpu), NULL); } EXPORT_SYMBOL_GPL(cpufreq_remove_update_util_hook); + +/** + * cpufreq_this_cpu_can_update - Check if cpufreq policy can be updated. + * @policy: cpufreq policy to check. + * + * Return 'true' if: + * - the local and remote CPUs share @policy, + * - dvfs_possible_from_any_cpu is set in @policy and the local CPU is not going + * offline (in which case it is not expected to run cpufreq updates any more). + */ +bool cpufreq_this_cpu_can_update(struct cpufreq_policy *policy) +{ + return cpumask_test_cpu(smp_processor_id(), policy->cpus) || + (policy->dvfs_possible_from_any_cpu && + rcu_dereference_sched(*this_cpu_ptr(&cpufreq_update_util_data))); +} diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 322ca8860f54..9b8916fd00a2 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -82,12 +82,10 @@ static bool sugov_should_update_freq(struct sugov_policy *sg_policy, u64 time) * by the hardware, as calculating the frequency is pointless if * we cannot in fact act on it. * - * For the slow switching platforms, the kthread is always scheduled on - * the right set of CPUs and any CPU can find the next frequency and - * schedule the kthread. + * This is needed on the slow switching platforms too to prevent CPUs + * going offline from leaving stale IRQ work items behind. */ - if (sg_policy->policy->fast_switch_enabled && - !cpufreq_this_cpu_can_update(sg_policy->policy)) + if (!cpufreq_this_cpu_can_update(sg_policy->policy)) return false; if (unlikely(sg_policy->limits_changed)) { |