9e0bc36ab0
When cpufreq's policy is 'single', there is a scenario that will cause sg_policy's next_freq to be unable to update. When the CPU's util is always max, the cpufreq will be max, and then if we change the policy's scaling_max_freq to be a lower freq, indeed, the sg_policy's next_freq need change to be the lower freq, however, because the cpu_is_busy, the next_freq would keep the max_freq. For example: The cpu7 is a single CPU: unisoc:/sys/devices/system/cpu/cpufreq/policy7 # while true;do done& [1] 4737 unisoc:/sys/devices/system/cpu/cpufreq/policy7 # taskset -p 80 4737 pid 4737's current affinity mask: ff pid 4737's new affinity mask: 80 unisoc:/sys/devices/system/cpu/cpufreq/policy7 # cat scaling_max_freq 2301000 unisoc:/sys/devices/system/cpu/cpufreq/policy7 # cat scaling_cur_freq 2301000 unisoc:/sys/devices/system/cpu/cpufreq/policy7 # echo 2171000 > scaling_max_freq unisoc:/sys/devices/system/cpu/cpufreq/policy7 # cat scaling_max_freq 2171000 At this time, the sg_policy's next_freq would stay at 2301000, which is wrong. To fix this, add a check for the ->need_freq_update flag. [ mingo: Clarified the changelog. ] Co-developed-by: Guohua Yan <guohua.yan@unisoc.com> Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com> Signed-off-by: Guohua Yan <guohua.yan@unisoc.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230719130527.8074-1-xuewen.yan@unisoc.com |
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| .. | ||
| autogroup.c | ||
| autogroup.h | ||
| build_policy.c | ||
| build_utility.c | ||
| clock.c | ||
| completion.c | ||
| core_sched.c | ||
| core.c | ||
| cpuacct.c | ||
| cpudeadline.c | ||
| cpudeadline.h | ||
| cpufreq_schedutil.c | ||
| cpufreq.c | ||
| cpupri.c | ||
| cpupri.h | ||
| cputime.c | ||
| deadline.c | ||
| debug.c | ||
| fair.c | ||
| features.h | ||
| idle.c | ||
| isolation.c | ||
| loadavg.c | ||
| Makefile | ||
| membarrier.c | ||
| pelt.c | ||
| pelt.h | ||
| psi.c | ||
| rt.c | ||
| sched-pelt.h | ||
| sched.h | ||
| smp.h | ||
| stats.c | ||
| stats.h | ||
| stop_task.c | ||
| swait.c | ||
| topology.c | ||
| wait_bit.c | ||
| wait.c | ||