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| author | Liao Chang <liaochang1@huawei.com> | 2023-09-12 08:10:57 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2023-10-06 22:01:26 +0200 |
| commit | 9ef0ad49cc860c0860026c01abea68878c6d72f7 (patch) | |
| tree | 9d12431d3cd6738ecfa220138d752055e51cb344 /drivers/cpufreq | |
| parent | cpufreq: userspace: Use fine-grained mutex in userspace governor (diff) | |
| download | linux-9ef0ad49cc860c0860026c01abea68878c6d72f7.tar.xz linux-9ef0ad49cc860c0860026c01abea68878c6d72f7.zip | |
cpufreq: userspace: Move is_managed indicator into per-policy structure
The userspace governor uses the 'cpu' field of cpufreq_policy structure
to track if it is allowed to set the speed of the policy.
However, there is a window where the 'cpu' field is equal to the value
of nr_cpus_id when all affected CPUs of policy are offline, which is an
illegal value to get the per-CPU variable.
To avoid this issue, modify the governor to use a per-policy indicator
to track if the policy is managed.
Signed-off-by: Liao Chang <liaochang1@huawei.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpufreq')
| -rw-r--r-- | drivers/cpufreq/cpufreq_userspace.c | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/drivers/cpufreq/cpufreq_userspace.c b/drivers/cpufreq/cpufreq_userspace.c index 442e31060d62..2c42fee76daa 100644 --- a/drivers/cpufreq/cpufreq_userspace.c +++ b/drivers/cpufreq/cpufreq_userspace.c @@ -15,9 +15,8 @@ #include <linux/mutex.h> #include <linux/slab.h> -static DEFINE_PER_CPU(unsigned int, cpu_is_managed); - struct userspace_policy { + unsigned int is_managed; unsigned int setspeed; struct mutex mutex; }; @@ -37,7 +36,7 @@ static int cpufreq_set(struct cpufreq_policy *policy, unsigned int freq) pr_debug("cpufreq_set for cpu %u, freq %u kHz\n", policy->cpu, freq); mutex_lock(&userspace->mutex); - if (!per_cpu(cpu_is_managed, policy->cpu)) + if (!userspace->is_managed) goto err; userspace->setspeed = freq; @@ -85,7 +84,7 @@ static int cpufreq_userspace_policy_start(struct cpufreq_policy *policy) pr_debug("started managing cpu %u\n", policy->cpu); mutex_lock(&userspace->mutex); - per_cpu(cpu_is_managed, policy->cpu) = 1; + userspace->is_managed = 1; userspace->setspeed = policy->cur; mutex_unlock(&userspace->mutex); return 0; @@ -98,7 +97,7 @@ static void cpufreq_userspace_policy_stop(struct cpufreq_policy *policy) pr_debug("managing cpu %u stopped\n", policy->cpu); mutex_lock(&userspace->mutex); - per_cpu(cpu_is_managed, policy->cpu) = 0; + userspace->is_managed = 0; userspace->setspeed = 0; mutex_unlock(&userspace->mutex); } |