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author | Viresh Kumar <viresh.kumar@linaro.org> | 2018-05-10 15:00:29 +0530 |
---|---|---|
committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2018-05-13 11:09:00 +0200 |
commit | 20b5324d8353d66e68e8c40031e438c247cf2d65 (patch) | |
tree | cc8c984b34862a8435e5ae92c471986be503d1b9 /drivers/cpufreq | |
parent | 130fccd09f0230aad5582a41f771b3b44149d32c (diff) | |
download | linux-20b5324d8353d66e68e8c40031e438c247cf2d65.tar.bz2 |
cpufreq: optimize cpufreq_notify_transition()
cpufreq_notify_transition() calls __cpufreq_notify_transition() for each
CPU of a policy. There is a lot of code in __cpufreq_notify_transition()
though which isn't required to be executed for each CPU, like checking
about disabled cpufreq or irqs, adjusting jiffies, updating cpufreq
stats and some debug print messages.
This commit merges __cpufreq_notify_transition() into
cpufreq_notify_transition() and modifies cpufreq_notify_transition() to
execute minimum amount of code for each CPU.
Also fix the kerneldoc for cpufreq_notify_transition() while at it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r-- | drivers/cpufreq/cpufreq.c | 63 |
1 files changed, 32 insertions, 31 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 075d18f6ba7a..b79c5324767c 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -300,8 +300,19 @@ static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) #endif } -static void __cpufreq_notify_transition(struct cpufreq_policy *policy, - struct cpufreq_freqs *freqs, unsigned int state) +/** + * cpufreq_notify_transition - Notify frequency transition and adjust_jiffies. + * @policy: cpufreq policy to enable fast frequency switching for. + * @freqs: contain details of the frequency update. + * @state: set to CPUFREQ_PRECHANGE or CPUFREQ_POSTCHANGE. + * + * This function calls the transition notifiers and the "adjust_jiffies" + * function. It is called twice on all CPU frequency changes that have + * external effects. + */ +static void cpufreq_notify_transition(struct cpufreq_policy *policy, + struct cpufreq_freqs *freqs, + unsigned int state) { BUG_ON(irqs_disabled()); @@ -313,54 +324,44 @@ static void __cpufreq_notify_transition(struct cpufreq_policy *policy, state, freqs->new); switch (state) { - case CPUFREQ_PRECHANGE: - /* detect if the driver reported a value as "old frequency" + /* + * Detect if the driver reported a value as "old frequency" * which is not equal to what the cpufreq core thinks is * "old frequency". */ if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { - if ((policy) && (policy->cpu == freqs->cpu) && - (policy->cur) && (policy->cur != freqs->old)) { + if (policy->cur && (policy->cur != freqs->old)) { pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n", freqs->old, policy->cur); freqs->old = policy->cur; } } - srcu_notifier_call_chain(&cpufreq_transition_notifier_list, - CPUFREQ_PRECHANGE, freqs); + + for_each_cpu(freqs->cpu, policy->cpus) { + srcu_notifier_call_chain(&cpufreq_transition_notifier_list, + CPUFREQ_PRECHANGE, freqs); + } + adjust_jiffies(CPUFREQ_PRECHANGE, freqs); break; case CPUFREQ_POSTCHANGE: adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); - pr_debug("FREQ: %lu - CPU: %lu\n", - (unsigned long)freqs->new, (unsigned long)freqs->cpu); - trace_cpu_frequency(freqs->new, freqs->cpu); + pr_debug("FREQ: %u - CPUs: %*pbl\n", freqs->new, + cpumask_pr_args(policy->cpus)); + + for_each_cpu(freqs->cpu, policy->cpus) { + trace_cpu_frequency(freqs->new, freqs->cpu); + srcu_notifier_call_chain(&cpufreq_transition_notifier_list, + CPUFREQ_POSTCHANGE, freqs); + } + cpufreq_stats_record_transition(policy, freqs->new); - srcu_notifier_call_chain(&cpufreq_transition_notifier_list, - CPUFREQ_POSTCHANGE, freqs); - if (likely(policy) && likely(policy->cpu == freqs->cpu)) - policy->cur = freqs->new; - break; + policy->cur = freqs->new; } } -/** - * cpufreq_notify_transition - call notifier chain and adjust_jiffies - * on frequency transition. - * - * This function calls the transition notifiers and the "adjust_jiffies" - * function. It is called twice on all CPU frequency changes that have - * external effects. - */ -static void cpufreq_notify_transition(struct cpufreq_policy *policy, - struct cpufreq_freqs *freqs, unsigned int state) -{ - for_each_cpu(freqs->cpu, policy->cpus) - __cpufreq_notify_transition(policy, freqs, state); -} - /* Do post notifications when there are chances that transition has failed */ static void cpufreq_notify_post_transition(struct cpufreq_policy *policy, struct cpufreq_freqs *freqs, int transition_failed) |