On Thursday, May 24, 2018 10:47:54 AM CEST Daniel Lezcano wrote: > On 24/05/2018 10:28, Rafael J. Wysocki wrote: > > On Thursday, May 24, 2018 10:14:31 AM CEST Daniel Lezcano wrote: > >> > >> Hi all, > > > > Hi, > > > >> would it be interesting to add debugfs metrics for cpuidle in order > >> to read some statistics from there and investigate the behavior ? > > > > What exactly would you like to see in there? > > It could be interesting to have statistics on a per cpu and global basis > for: > > - prediction accuracy: > > /sys/kernel/debug/cpuidle/prediction/[good|over|under] > /sys/kernel/debug/cpuidle/cpu*/state*/prediction/[good|over|under] > > - exit latency > > In addition, it is often the case the idle states values are dropped > randomly, it is interesting to see the average exit latency for the > states. That could give also an indication the cluster idle state success. > > /sys/kernel/debug/cpuidle/state*/latency/[min|max|avg|stddev] > /sys/kernel/debug/cpuidle/cpu*/state*/prediction/[min|max|avg|stddev] > > And perhaps more information like the tick stopped stat ?
Fair enough, but that must be minimum overhead.
