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(-)
--
2.25.0.rc1.19.g042ed3e048af
