Hi Rafael, On 2018.12.03 04:32 Rafael J. Wysocki wrote: > Add two new metrics for CPU idle states, "high" and "low", to count > the number of times the given state had been asked for (or entered > from the kernel's perspective), but the observed idle duration turned > out to be too high or too low for it (respectively). I wonder about the "high" "low" terminology here. > These mertics help to estimat the quality of the CPU idle governor > in use. Yes, very useful. Thanks. Here the terms are mixed with "deep" and "shallow" > + unsigned long long high; /* Number of times it's been too deep */ > + unsigned long long low; /* Number of times it's been too shallow */ > +``high`` > + Total number of times this idle state had been asked for, but the > + observed idle duration was too short to match its target residency. > + O.K. To avoid ambiguity, how about naming them "too_short" and "too_long"? > +``low`` > + Total number of times this idle state had been asked for, but a deeper > + idle state would have been a better match for the observed idle duration. Even though I read the patch, by the time I actually looked at the numbers I had forgotten the meaning. I had look at idle state 0 and 4 (the deepest for my computer) to figure it out: doug@s15:~/c$ cat /sys/devices/system/cpu/cpu0/cpuidle/state0/low 259871 doug@s15:~/c$ cat /sys/devices/system/cpu/cpu0/cpuidle/state0/high 0 doug@s15:~/c$ cat /sys/devices/system/cpu/cpu0/cpuidle/state4/low 0 doug@s15:~/c$ cat /sys/devices/system/cpu/cpu0/cpuidle/state4/high 5584 Because state 0 can not be too short and state 4 can not be too long. ... Doug
