On 09/10/23 11:30, Shrikanth Hegde wrote: > sysctl sched_energy_aware is available for the admin to disable/enable > energy aware scheduling(EAS). EAS is enabled only if few conditions are > met by the platform. They are, asymmetric CPU capacity, no SMT, > schedutil CPUfreq governor, frequency invariant load tracking etc. > A platform may boot without EAS capability, but could gain such > capability at runtime. For example, changing/registering the CPUfreq > governor to schedutil. > > At present, though platform doesn't support EAS, this sysctl returns 1 > and it ends up calling build_perf_domains on write to 1 and > NOP when writing to 0. That is confusing and un-necessary. > > Desired behavior would be to have this sysctl to enable/disable the EAS > on supported platform. On non-supported platform write to the sysctl > would return not supported error and read of the sysctl would return > empty. So > sched_energy_aware returns empty - EAS is not possible at this moment > This will include EAS capable platforms which have at least one EAS > condition false during startup, e.g. not using the schedutil CPUfreq governor > sched_energy_aware returns 0 - EAS is supported but disabled by admin. > sched_energy_aware returns 1 - EAS is supported and enabled. > > User can find out the reason why EAS is not possible by checking > info messages. sched_is_eas_possible returns true if the platform > can do EAS at this moment. > > Tested-by: Pierre Gondois <pierre.gondois@xxxxxxx> > Signed-off-by: Shrikanth Hegde <sshegde@xxxxxxxxxxxxxxxxxx> Reviewed-by: Valentin Schneider <vschneid@xxxxxxxxxx>
