Currently, raw cache will be reset when next_f is changed after get_next_freq for correctness. However, it may introduce more cycles. This patch changes it to maintain the cached value instead of dropping it.
This is adapted from https://android-review.googlesource.com/1352810/ Signed-off-by: Wei Wang <w...@google.com> --- kernel/sched/cpufreq_schedutil.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 5ae7b4e6e8d6..ae3ae7fcd027 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -31,6 +31,7 @@ struct sugov_policy { s64 freq_update_delay_ns; unsigned int next_freq; unsigned int cached_raw_freq; + unsigned int prev_cached_raw_freq; /* The next fields are only needed if fast switch cannot be used: */ struct irq_work irq_work; @@ -165,6 +166,7 @@ static unsigned int get_next_freq(struct sugov_policy *sg_policy, return sg_policy->next_freq; sg_policy->need_freq_update = false; + sg_policy->prev_cached_raw_freq = sg_policy->cached_raw_freq; sg_policy->cached_raw_freq = freq; return cpufreq_driver_resolve_freq(policy, freq); } @@ -464,8 +466,8 @@ static void sugov_update_single(struct update_util_data *hook, u64 time, if (busy && next_f < sg_policy->next_freq) { next_f = sg_policy->next_freq; - /* Reset cached freq as next_freq has changed */ - sg_policy->cached_raw_freq = 0; + /* Restore cached freq as next_freq has changed */ + sg_policy->cached_raw_freq = sg_policy->prev_cached_raw_freq; } /* @@ -828,6 +830,7 @@ static int sugov_start(struct cpufreq_policy *policy) sg_policy->limits_changed = false; sg_policy->need_freq_update = false; sg_policy->cached_raw_freq = 0; + sg_policy->prev_cached_raw_freq = 0; for_each_cpu(cpu, policy->cpus) { struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu); -- 2.29.0.rc1.297.gfa9743e501-goog
