From: Lukasz Luba lukasz.luba@arm.com
stable inclusion from stable-5.10.50 commit f2b240047644ddc62d0652d65b84e9dc42e90a9a bugzilla: 174522 https://gitee.com/openeuler/kernel/issues/I4DNFY
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit 2ad8ccc17d1e4270cf65a3f2a07a7534aa23e3fb ]
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 Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Chen Jun chenjun102@huawei.com Acked-by: Weilong Chen chenweilong@huawei.com Signed-off-by: Chen Jun chenjun102@huawei.com --- drivers/thermal/cpufreq_cooling.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/thermal/cpufreq_cooling.c b/drivers/thermal/cpufreq_cooling.c index 3f6a69ccc173..6e1d6a31ee4f 100644 --- a/drivers/thermal/cpufreq_cooling.c +++ b/drivers/thermal/cpufreq_cooling.c @@ -443,7 +443,7 @@ static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev, ret = freq_qos_update_request(&cpufreq_cdev->qos_req, frequency); if (ret >= 0) { cpufreq_cdev->cpufreq_state = state; - cpus = cpufreq_cdev->policy->cpus; + cpus = cpufreq_cdev->policy->related_cpus; max_capacity = arch_scale_cpu_capacity(cpumask_first(cpus)); capacity = frequency * max_capacity; capacity /= cpufreq_cdev->policy->cpuinfo.max_freq;