[PATCH 0/2] sched/cpufreq: Fix schedutil's boost frequency handling

[Sibi Sankar]

capacity_freq_ref, exposed to schedutil via get_capacity_ref_freq(),
was introduced by commit 9942cb22ea45 ("sched/topology: Add a new
arch_scale_freq_ref() method") as a fixed anchor that does not move at
runtime. However, schedutil uses that same fixed anchor as the reference
plugged into map_util_freq() which saturates exactly at capacity_freq_ref.
As a result, a system with cpufreq boost enabled effectively never runs at
boost frequencies under schedutil-governed load.

This series fixes this by plugging in policy-max into the map_util_freq
equation and allowing cpuinfo max to fallback to a non-boost value when
disabled.

Drivers that rely on the current behaviour (upward bump only) may be
affected; We should handle such cases in the driver side without
breaking core behaviour.

Logs:

# cd /sys/devices/system/cpu/cpufreq/
# ls
boost  policy0  policy12  policy6
# cat boost
0
# cat policy6/scaling_max_freq
4454400
# echo 1 > boost
# cat policy6/scaling_max_freq
4723200
# echo 0 > boost
# cat policy6/scaling_max_freq
4723200

# echo 1 > boost
# cat policy6/stats/time_in_state
355200 36958
4454400 650
4588800 0
4723200 0
#

Logs: With this series

# cd /sys/devices/system/cpu/cpufreq/
# ls
boost  policy0  policy12  policy6
# cat boost
0
# cat policy6/scaling_max_freq
4454400
# echo 1 > boost
# cat policy6/scaling_max_freq
4723200
# echo 0 > policy6/boost
# cat policy6/scaling_max_freq
4454400

# cat policy6/boost
0

# cat policy6/stats/time_in_state
355200 40147
4454400 79
4588800 0
4723200 0

# echo 1 > policy6/boost

# cat policy6/stats/time_in_state
355200 44834
4454400 93
4588800 25
4723200 569

Ananthu C V (1):
  cpufreq: allow cpuinfo max to decrease when boost is disabled

Sibi Sankar (1):
  sched/cpufreq: Update schedutil's DVFS request to reach the boost
    frequencies

 drivers/cpufreq/freq_table.c     |  7 +------
 kernel/sched/cpufreq_schedutil.c | 13 ++++++++++---
 2 files changed, 11 insertions(+), 9 deletions(-)


base-commit: 0f6da28aab51b16762ed82e8fdeaa5042da45b08
-- 
2.34.1