diff options
| author | Chris Redpath <chris.redpath@arm.com> | 2017-05-25 15:22:59 +0100 |
|---|---|---|
| committer | Andres Oportus <andresoportus@google.com> | 2017-07-18 18:18:40 +0000 |
| commit | a8a200d83b1ff334a6c607b8fda848551648689b (patch) | |
| tree | c0b88feb76a1c64385de0300c97dcfaa8c13f62a /kernel/sched/cpufreq_schedutil.c | |
| parent | 7378c38a80fc434f8d6cf61167d843ca388468b5 (diff) | |
UPSTREAM: cpufreq: schedutil: Refactor sugov_next_freq_shared()
The loop in sugov_next_freq_shared() contains an if block to skip the
loop for the current CPU. This turns out to be an unnecessary
conditional in the scheduler's hot-path for every CPU in the policy.
It would be better to drop the conditional and make the loop treat all
the CPUs in the same way. That would eliminate the need of calling
sugov_iowait_boost() at the top of the routine.
To keep the code optimized to return early if the current CPU has RT/DL
flags set, move the flags check to sugov_update_shared() instead in
order to avoid the function call entirely.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
(cherry picked from commit cba1dfb57b94c234728b689d9b00d4267fa1a879)
(modified for SCHED_CPUFREQ_DL vs SCHED_CPUFREQ_RT)
Signed-off-by: Chris Redpath <chris.redpath@arm.com>
Change-Id: Ie046fdc8eda46821356750edd0fb6f7d077af363
Diffstat (limited to 'kernel/sched/cpufreq_schedutil.c')
| -rw-r--r-- | kernel/sched/cpufreq_schedutil.c | 25 |
1 files changed, 9 insertions, 16 deletions
diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 3a9283640f84..e1a2ed98991f 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -272,30 +272,19 @@ static void sugov_update_single(struct update_util_data *hook, u64 time, sugov_update_commit(sg_policy, time, next_f); } -static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, - unsigned long util, unsigned long max, - unsigned int flags) +static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu) { struct sugov_policy *sg_policy = sg_cpu->sg_policy; struct cpufreq_policy *policy = sg_policy->policy; - unsigned int max_f = policy->cpuinfo.max_freq; u64 last_freq_update_time = sg_policy->last_freq_update_time; + unsigned long util = 0, max = 1; unsigned int j; - if (flags & SCHED_CPUFREQ_DL) - return max_f; - - sugov_iowait_boost(sg_cpu, &util, &max); - for_each_cpu(j, policy->cpus) { - struct sugov_cpu *j_sg_cpu; + struct sugov_cpu *j_sg_cpu = &per_cpu(sugov_cpu, j); unsigned long j_util, j_max; s64 delta_ns; - if (j == smp_processor_id()) - continue; - - j_sg_cpu = &per_cpu(sugov_cpu, j); /* * If the CPU utilization was last updated before the previous * frequency update and the time elapsed between the last update @@ -309,7 +298,7 @@ static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, continue; } if (j_sg_cpu->flags & SCHED_CPUFREQ_DL) - return max_f; + return policy->cpuinfo.max_freq; j_util = j_sg_cpu->util; j_max = j_sg_cpu->max; @@ -344,7 +333,11 @@ static void sugov_update_shared(struct update_util_data *hook, u64 time, sg_cpu->last_update = time; if (sugov_should_update_freq(sg_policy, time)) { - next_f = sugov_next_freq_shared(sg_cpu, util, max, flags); + if (flags & SCHED_CPUFREQ_DL) + next_f = sg_policy->policy->cpuinfo.max_freq; + else + next_f = sugov_next_freq_shared(sg_cpu); + sugov_update_commit(sg_policy, time, next_f); } |