* Mike Galbraith <umgwanakikb...@gmail.com> wrote: > On Mon, 2015-08-24 at 09:41 +0200, Ingo Molnar wrote: > > * Mike Galbraith <umgwanakikb...@gmail.com> wrote: > > > > > On Mon, 2015-08-24 at 08:44 +0200, Ingo Molnar wrote: > > > > > > > the 'housekeeping CPU' is essentially the boot CPU. Yet we dedicate a > > > > full mask to > > > > it (housekeeping_mask - a variable mask to begin with) and recover the > > > > housekeeping CPU via: > > > > > > > > + return cpumask_any_and(housekeeping_mask, cpu_online_mask); > > > > > > There can be, and had better be if box is big, multiple housekeepers. > > > > Yes - but that does not seem to be possible via the code right now AFAICS, > > so > > at minimum it's incomplete. > > In master housekeepers are set up in tick_nohz_init(). Everybody who's not a > nohz_full CPU is a housekeeper.
Ah, indeed, I missed the nohz_full= boot option: static int __init tick_nohz_full_setup(char *str) { alloc_bootmem_cpumask_var(&tick_nohz_full_mask); if (cpulist_parse(str, tick_nohz_full_mask) < 0) { Ok, first question is resolved - but the second one, behavior on boot CPU unplug still holds. Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/