cpufreq: interactive: Implement cluster-based min_sample_time

min_sample_time needs to be cluster-based to match
above_hispeed_delay. If each CPU keeps making local decisions, it's
possible min_sample_time is not correctly enforced at cluster level,
which results in undesired frequency drops.

Change-Id: Ia2ec2ad9b7a8d715d4408c924d6762b7e532e4b4
Reviewed-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Junjie Wu <junjiew@codeaurora.org>

diff --git a/drivers/cpufreq/cpufreq_interactive.c b/drivers/cpufreq/cpufreq_interactive.c
index 3f9d8f43fc48d7e1a6cf8feff76ffecd4a746171..52c551d584770118423e85dd0fe9a4cd5a56edf1 100644 (file)
--- a/drivers/cpufreq/cpufreq_interactive.c
+++ b/drivers/cpufreq/cpufreq_interactive.c
@@ -48,7 +48,8 @@ struct cpufreq_interactive_cpuinfo {
        unsigned int target_freq;
        unsigned int floor_freq;
        unsigned int max_freq;
-       u64 floor_validate_time;
+       u64 pol_floor_val_time; /* policy floor_validate_time */
+       u64 loc_floor_val_time; /* per-cpu floor_validate_time */
        u64 pol_hispeed_val_time; /* policy hispeed_validate_time */
        u64 loc_hispeed_val_time; /* per-cpu hispeed_validate_time */
        struct rw_semaphore enable_sem;
@@ -346,6 +347,7 @@ static void cpufreq_interactive_timer(unsigned long data)
        unsigned int loadadjfreq;
        unsigned int index;
        unsigned long flags;
+       u64 max_fvtime;
 
        if (!down_read_trylock(&pcpu->enable_sem))
                return;
@@ -409,9 +411,10 @@ static void cpufreq_interactive_timer(unsigned long data)
         * Do not scale below floor_freq unless we have been at or above the
         * floor frequency for the minimum sample time since last validated.
         */
-       if (new_freq < pcpu->floor_freq) {
-               if (now - pcpu->floor_validate_time <
-                               tunables->min_sample_time) {
+       max_fvtime = max(pcpu->pol_floor_val_time, pcpu->loc_floor_val_time);
+       if (new_freq < pcpu->floor_freq &&
+           pcpu->target_freq >= pcpu->policy->cur) {
+               if (now - max_fvtime < tunables->min_sample_time) {
                        trace_cpufreq_interactive_notyet(
                                data, cpu_load, pcpu->target_freq,
                                pcpu->policy->cur, new_freq);
@@ -430,7 +433,9 @@ static void cpufreq_interactive_timer(unsigned long data)
 
        if (!tunables->boosted || new_freq > tunables->hispeed_freq) {
                pcpu->floor_freq = new_freq;
-               pcpu->floor_validate_time = now;
+               if (pcpu->target_freq >= pcpu->policy->cur ||
+                   new_freq >= pcpu->policy->cur)
+                       pcpu->loc_floor_val_time = now;
        }
 
        if (pcpu->target_freq == new_freq &&
@@ -555,7 +560,7 @@ static int cpufreq_interactive_speedchange_task(void *data)
                        unsigned int j;
                        unsigned int max_freq = 0;
                        struct cpufreq_interactive_cpuinfo *pjcpu;
-                       u64 hvt = ~0ULL;
+                       u64 hvt = ~0ULL, fvt = 0;
 
                        pcpu = &per_cpu(cpuinfo, cpu);
                        if (!down_read_trylock(&pcpu->enable_sem))
@@ -568,6 +573,7 @@ static int cpufreq_interactive_speedchange_task(void *data)
                        for_each_cpu(j, pcpu->policy->cpus) {
                                pjcpu = &per_cpu(cpuinfo, j);
 
+                               fvt = max(fvt, pjcpu->loc_floor_val_time);
                                if (pjcpu->target_freq > max_freq) {
                                        max_freq = pjcpu->target_freq;
                                        hvt = pjcpu->loc_hispeed_val_time;
@@ -575,6 +581,10 @@ static int cpufreq_interactive_speedchange_task(void *data)
                                        hvt = min(hvt, pjcpu->loc_hispeed_val_time);
                                }
                        }
+                       for_each_cpu(j, pcpu->policy->cpus) {
+                               pjcpu = &per_cpu(cpuinfo, j);
+                               pjcpu->pol_floor_val_time = fvt;
+                       }
 
                        if (max_freq != pcpu->policy->cur) {
                                __cpufreq_driver_target(pcpu->policy,
@@ -1243,11 +1253,11 @@ static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
                        pcpu->target_freq = policy->cur;
                        pcpu->freq_table = freq_table;
                        pcpu->floor_freq = pcpu->target_freq;
-                       pcpu->floor_validate_time =
+                       pcpu->pol_floor_val_time =
                                ktime_to_us(ktime_get());
-                       pcpu->pol_hispeed_val_time =
-                               pcpu->floor_validate_time;
-                       pcpu->loc_hispeed_val_time = pcpu->floor_validate_time;
+                       pcpu->loc_floor_val_time = pcpu->pol_floor_val_time;
+                       pcpu->pol_hispeed_val_time = pcpu->pol_floor_val_time;
+                       pcpu->loc_hispeed_val_time = pcpu->pol_floor_val_time;
                        pcpu->max_freq = policy->max;
                        down_write(&pcpu->enable_sem);
                        del_timer_sync(&pcpu->cpu_timer);