thermal/cpufreq_cooling: Update offline CPUs per-cpu thermal_pressure
authorLukasz Luba <lukasz.luba@arm.com>
Mon, 14 Jun 2021 19:10:30 +0000 (20:10 +0100)
committerPeter Zijlstra <peterz@infradead.org>
Thu, 17 Jun 2021 12:11:43 +0000 (14:11 +0200)
commit2ad8ccc17d1e4270cf65a3f2a07a7534aa23e3fb
tree3bf363a327cd94889d6cc8c6b16be5ec8d6516b8
parent83c5e9d573e1f0757f324d01adb6ee77b49c3f0e
thermal/cpufreq_cooling: Update offline CPUs per-cpu thermal_pressure

The thermal pressure signal gives information to the scheduler about
reduced CPU capacity due to thermal. It is based on a value stored in
a per-cpu 'thermal_pressure' variable. The online CPUs will get the
new value there, while the offline won't. Unfortunately, when the CPU
is back online, the value read from per-cpu variable might be wrong
(stale data).  This might affect the scheduler decisions, since it
sees the CPU capacity differently than what is actually available.

Fix it by making sure that all online+offline CPUs would get the
proper value in their per-cpu variable when thermal framework sets
capping.

Fixes: f12e4f66ab6a3 ("thermal/cpu-cooling: Update thermal pressure in case of a maximum frequency capping")
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/r/20210614191030.22241-1-lukasz.luba@arm.com
drivers/thermal/cpufreq_cooling.c