On Fri, Oct 16, 2020 at 6:36 PM Wei Wang <[email protected]> wrote: > > 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.
IMV you need to be more specific about why this helps. > This is adapted from https://android-review.googlesource.com/1352810/ > > Signed-off-by: Wei Wang <[email protected]> > --- > 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 >
