cpufreq: Call transition notifier only once for each policy

Currently, the notifiers are called once for each CPU of the policy->cpus
cpumask. It would be more optimal if the notifier can be called only
once and all the relevant information be provided to it. Out of the 23
drivers that register for the transition notifiers today, only 4 of them
do per-cpu updates and the callback for the rest can be called only once
for the policy without any impact.

This would also avoid multiple function calls to the notifier callbacks
and reduce multiple iterations of notifier core's code (which does
locking as well).

This patch adds pointer to the cpufreq policy to the struct
cpufreq_freqs, so the notifier callback has all the information
available to it with a single call. The five drivers which perform
per-cpu updates are updated to use the cpufreq policy. The freqs->cpu
field is redundant now and is removed.

Acked-by: David S. Miller <davem@davemloft.net> (sparc)
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 7 insertions, 7 deletions

diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 684caf067003..d01a74fbc4db 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -42,13 +42,6 @@ enum cpufreq_table_sorting {
 	CPUFREQ_TABLE_SORTED_DESCENDING
 };
 
-struct cpufreq_freqs {
-	unsigned int cpu;	/* cpu nr */
-	unsigned int old;
-	unsigned int new;
-	u8 flags;		/* flags of cpufreq_driver, see below. */
-};
-
 struct cpufreq_cpuinfo {
 	unsigned int		max_freq;
 	unsigned int		min_freq;
@@ -156,6 +149,13 @@ struct cpufreq_policy {
 	struct thermal_cooling_device *cdev;
 };
 
+struct cpufreq_freqs {
+	struct cpufreq_policy *policy;
+	unsigned int old;
+	unsigned int new;
+	u8 flags;		/* flags of cpufreq_driver, see below. */
+};
+
 /* Only for ACPI */
 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
 #define CPUFREQ_SHARED_TYPE_HW	 (1) /* HW does needed coordination */