| Message ID | cover.1601884370.git.viresh.kumar@linaro.org |
|---|---|
| Headers | show |
| Series | cpufreq: Record stats with fast-switching | expand |
On Mon, Oct 5, 2020 at 9:56 AM Viresh Kumar <viresh.kumar@linaro.org> wrote: > > Hi, > > We disabled recording cpufreq stats when fast switching was introduced > to the cpufreq core as the cpufreq stats required to take a spinlock and > that can't be allowed (for performance reasons) on scheduler's hot path. > > Here is an attempt to get rid of the lock and bring back the support. > > V2->V3: > - Use READ/WRITE_ONCE() for reset-time as well. > - Use unlikely for few conditionals in the hot path. > - Better changelogs. > - Rebase changes. > > V1-V2: > - Use READ_ONCE/WRITE_ONCE instead of atomic in the first patch. > > -- > Viresh > > Viresh Kumar (5): > cpufreq: stats: Defer stats update to > cpufreq_stats_record_transition() > cpufreq: stats: Remove locking > cpufreq: stats: Mark few conditionals with unlikely() > cpufreq: stats: Enable stats for fast-switch as well > cpufreq: Move traces and update to policy->cur to cpufreq core > > drivers/cpufreq/cpufreq.c | 11 ++++ > drivers/cpufreq/cpufreq_stats.c | 89 ++++++++++++++++++++------------ > kernel/sched/cpufreq_schedutil.c | 12 +---- > 3 files changed, 69 insertions(+), 43 deletions(-) > > -- The entire series applied as 5.10 material with some minor changelog edits in patch [1/5], thanks!
Hi, We disabled recording cpufreq stats when fast switching was introduced to the cpufreq core as the cpufreq stats required to take a spinlock and that can't be allowed (for performance reasons) on scheduler's hot path. Here is an attempt to get rid of the lock and bring back the support. V2->V3: - Use READ/WRITE_ONCE() for reset-time as well. - Use unlikely for few conditionals in the hot path. - Better changelogs. - Rebase changes. V1-V2: - Use READ_ONCE/WRITE_ONCE instead of atomic in the first patch. -- Viresh Viresh Kumar (5): cpufreq: stats: Defer stats update to cpufreq_stats_record_transition() cpufreq: stats: Remove locking cpufreq: stats: Mark few conditionals with unlikely() cpufreq: stats: Enable stats for fast-switch as well cpufreq: Move traces and update to policy->cur to cpufreq core drivers/cpufreq/cpufreq.c | 11 ++++ drivers/cpufreq/cpufreq_stats.c | 89 ++++++++++++++++++++------------ kernel/sched/cpufreq_schedutil.c | 12 +---- 3 files changed, 69 insertions(+), 43 deletions(-)