On 2017/10/14 8:59, Rafael J. Wysocki wrote: > On Saturday, September 30, 2017 9:20:32 AM CEST Aubrey Li wrote: >> Add a knob to make fast idle threshold tunable >> >> Signed-off-by: Aubrey Li <aubrey...@linux.intel.com> > > I first of all am not sure about the need to add a tunable for this at all > in the first place.
Actually I think a fixed value(10) might be good enough but not quite sure if there is a requirement to tune it for different scenario, for example even if the predicted idle interval is 100x overhead, I still want a fast path for a better benchmark score? >> @@ -1229,6 +1230,17 @@ static struct ctl_table kern_table[] = { >> .extra2 = &one, >> }, >> #endif >> +#ifdef CONFIG_CPU_IDLE >> + { >> + .procname = "fast_idle_ratio", >> + .data = &sysctl_fast_idle_ratio, >> + .maxlen = sizeof(int), >> + .mode = 0644, >> + .proc_handler = proc_dointvec_minmax, >> + .extra1 = &one, >> + .extra2 = &one_hundred, >> + }, >> +#endif >> { } >> }; >> > > And if there is a good enough reason to add it, shouldn't the tunable be > there in the cpuidle framework? > sure, if it makes sense, I'll move it into cpuidle/sysfs.c Thanks, -Aubrey