On Mon, Dec 19, 2016 at 3:29 PM, Samuel Thibault <[email protected]> wrote: > Paul Turner, on Mon 19 Dec 2016 15:26:19 -0800, wrote: >> >> > - if (shares < MIN_SHARES) >> >> > - shares = MIN_SHARES; >> > ... >> >> > return shares; >> > >> > This will only make sure that the returned shares is 2, not 2048. >> >> This is intentional. The MIN_SHARES you are seeing here is overloaded. >> Every "1" unit of share is "SCHED_LOAD_RESOLUTION" bits internally. > > I'm not talking about the SCHED_LOAD_RESOLUTION scaling, but about the > SCHED_FIXEDPOINT_SHIFT scaling, which is what > 2159197d6677 ("sched/core: Enable increased load resolution on 64-bit > kernels") > modified on 64bit platforms.
.... From that commit: """ -#if 0 /* BITS_PER_LONG > 32 -- currently broken: it increases power usage under light load */ +#ifdef CONFIG_64BIT # define SCHED_LOAD_RESOLUTION 10 # define scale_load(w) ((w) << SCHED_LOAD_RESOLUTION) # define scale_load_down(w) ((w) >> SCHED_LOAD_RESOLUTION) """ Please take a deeper look at the scale_load() interactions.
