| Message ID | d367fc6fda0f167678a83e1d70e0cfd240a32cbc.1372759022.git.viresh.kumar@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Tuesday, July 02, 2013 04:36:28 PM Viresh Kumar wrote: > Commit 7c30ed ("cpufreq: make sure frequency transitions are serialized") > interacts poorly with systems that have a single core freqency for all > cores. On such systems we have a single policy for all cores with > several CPUs. When we do a frequency transition the governor calls the > pre and post change notifiers which causes cpufreq_notify_transition() > per CPU. Since the policy is the same for all of them all CPUs after > the first and the warnings added are generated by checking a per-policy > flag the warnings will be triggered for all cores after the first. > > Fix this by allowing notifier to be called for n times. Where n is the number of > cpus in policy->cpus. > > Reported-and-Tested-by: Mark Brown <broonie@linaro.org> > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> > --- > Hi Rafael, > > This is a fix for 3.11. Queued up for 3.11. Thanks, Rafael > drivers/cpufreq/cpufreq.c | 7 ++++--- > include/linux/cpufreq.h | 2 +- > 2 files changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > index b557503..b7bda8d 100644 > --- a/drivers/cpufreq/cpufreq.c > +++ b/drivers/cpufreq/cpufreq.c > @@ -312,11 +312,12 @@ static void __cpufreq_notify_transition(struct cpufreq_policy *policy, > switch (state) { > > case CPUFREQ_PRECHANGE: > - if (WARN(policy->transition_ongoing, > + if (WARN(policy->transition_ongoing == > + cpumask_weight(policy->cpus), > "In middle of another frequency transition\n")) > return; > > - policy->transition_ongoing = true; > + policy->transition_ongoing++; > > /* detect if the driver reported a value as "old frequency" > * which is not equal to what the cpufreq core thinks is > @@ -341,7 +342,7 @@ static void __cpufreq_notify_transition(struct cpufreq_policy *policy, > "No frequency transition in progress\n")) > return; > > - policy->transition_ongoing = false; > + policy->transition_ongoing--; > > adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); > pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, > diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h > index 4d7390b..90d5a15 100644 > --- a/include/linux/cpufreq.h > +++ b/include/linux/cpufreq.h > @@ -119,7 +119,7 @@ struct cpufreq_policy { > > struct kobject kobj; > struct completion kobj_unregister; > - bool transition_ongoing; /* Tracks transition status */ > + int transition_ongoing; /* Tracks transition status */ > }; > > #define CPUFREQ_ADJUST (0) >
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index b557503..b7bda8d 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -312,11 +312,12 @@ static void __cpufreq_notify_transition(struct cpufreq_policy *policy, switch (state) { case CPUFREQ_PRECHANGE: - if (WARN(policy->transition_ongoing, + if (WARN(policy->transition_ongoing == + cpumask_weight(policy->cpus), "In middle of another frequency transition\n")) return; - policy->transition_ongoing = true; + policy->transition_ongoing++; /* detect if the driver reported a value as "old frequency" * which is not equal to what the cpufreq core thinks is @@ -341,7 +342,7 @@ static void __cpufreq_notify_transition(struct cpufreq_policy *policy, "No frequency transition in progress\n")) return; - policy->transition_ongoing = false; + policy->transition_ongoing--; adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 4d7390b..90d5a15 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -119,7 +119,7 @@ struct cpufreq_policy { struct kobject kobj; struct completion kobj_unregister; - bool transition_ongoing; /* Tracks transition status */ + int transition_ongoing; /* Tracks transition status */ }; #define CPUFREQ_ADJUST (0)
Commit 7c30ed ("cpufreq: make sure frequency transitions are serialized") interacts poorly with systems that have a single core freqency for all cores. On such systems we have a single policy for all cores with several CPUs. When we do a frequency transition the governor calls the pre and post change notifiers which causes cpufreq_notify_transition() per CPU. Since the policy is the same for all of them all CPUs after the first and the warnings added are generated by checking a per-policy flag the warnings will be triggered for all cores after the first. Fix this by allowing notifier to be called for n times. Where n is the number of cpus in policy->cpus. Reported-and-Tested-by: Mark Brown <broonie@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- Hi Rafael, This is a fix for 3.11. drivers/cpufreq/cpufreq.c | 7 ++++--- include/linux/cpufreq.h | 2 +- 2 files changed, 5 insertions(+), 4 deletions(-)