[V2,0/4] cpufreq: Record stats with fast-switching

Message

Viresh Kumar Sept. 16, 2020, 6:45 a.m. UTC

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.

V1-V2:
- Use READ_ONCE/WRITE_ONCE instead of atomic in the first patch.

--
Viresh

Viresh Kumar (4):
  cpufreq: stats: Defer stats update to
    cpufreq_stats_record_transition()
  cpufreq: stats: Remove locking
  cpufreq: stats: Enable stats for fast-switch as well
  cpufreq: Move traces and update to policy->cur to cpufreq core

 drivers/cpufreq/cpufreq.c        | 16 +++++-
 drivers/cpufreq/cpufreq_stats.c  | 87 ++++++++++++++++++++------------
 kernel/sched/cpufreq_schedutil.c | 12 +----
 3 files changed, 72 insertions(+), 43 deletions(-)


base-commit: 856deb866d16e29bd65952e0289066f6078af773