[PATCH 1/3] cpufreq: schedutil: move cached_raw_freq to struct sugov_policy

From: Viresh Kumar
Date: Thu Mar 02 2017 - 04:33:50 EST


cached_raw_freq applies to the entire cpufreq policy and not individual
CPUs. Apart from wasting per-cpu memory, it is actually wrong to keep it
in struct sugov_cpu as we may end up comparing next_freq with a stale
cached_raw_freq of a random CPU.

Move cached_raw_freq to struct sugov_policy.

Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
---
kernel/sched/cpufreq_schedutil.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index 306d97e7b57c..721f4e011366 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -35,6 +35,7 @@ struct sugov_policy {
u64 last_freq_update_time;
s64 freq_update_delay_ns;
unsigned int next_freq;
+ unsigned int cached_raw_freq;

/* The next fields are only needed if fast switch cannot be used. */
struct irq_work irq_work;
@@ -51,7 +52,6 @@ struct sugov_cpu {
struct update_util_data update_util;
struct sugov_policy *sg_policy;

- unsigned int cached_raw_freq;
unsigned long iowait_boost;
unsigned long iowait_boost_max;
u64 last_update;
@@ -145,9 +145,9 @@ static unsigned int get_next_freq(struct sugov_cpu *sg_cpu, unsigned long util,

freq = (freq + (freq >> 2)) * util / max;

- if (freq == sg_cpu->cached_raw_freq && sg_policy->next_freq != UINT_MAX)
+ if (freq == sg_policy->cached_raw_freq && sg_policy->next_freq != UINT_MAX)
return sg_policy->next_freq;
- sg_cpu->cached_raw_freq = freq;
+ sg_policy->cached_raw_freq = freq;
return cpufreq_driver_resolve_freq(policy, freq);
}

@@ -579,6 +579,7 @@ static int sugov_start(struct cpufreq_policy *policy)
sg_policy->next_freq = UINT_MAX;
sg_policy->work_in_progress = false;
sg_policy->need_freq_update = false;
+ sg_policy->cached_raw_freq = 0;

for_each_cpu(cpu, policy->cpus) {
struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu);
@@ -589,7 +590,6 @@ static int sugov_start(struct cpufreq_policy *policy)
sg_cpu->max = 0;
sg_cpu->flags = SCHED_CPUFREQ_RT;
sg_cpu->last_update = 0;
- sg_cpu->cached_raw_freq = 0;
sg_cpu->iowait_boost = 0;
sg_cpu->iowait_boost_max = policy->cpuinfo.max_freq;
cpufreq_add_update_util_hook(cpu, &sg_cpu->update_util,
--
2.7.1.410.g6faf27b