On 27 March 2013 09:46, Peter Zijlstra <pet...@infradead.org> wrote: > On Tue, 2013-03-26 at 08:29 -0700, Arjan van de Ven wrote: >> > Isn't this basically related to picking the NO_HZ cpu; if the system >> > isn't fully symmetric with its power gates you want the NO_HZ cpu to be >> > the 'special' cpu. If it is symmetric we really don't care which core >> > is left 'running' and we can even select a new pack cpu from the idle >> > cores once the old one is fully utilized. >> >> you don't really care much sure, but there's some advantages for sorting >> "all the way left", >> e.g. to linux cpu 0. >> Some tasks only run there, and interrupts tend to be favored to that cpu as >> well on x86. > > Right, and I suspect all the big-little nonsense will have the little > cores on low numbers as well (is this architected or can a creative > licensee screw us over?)
It's not mandatory to have little cores on low numbers even if it's advised > > So find_new_ilb() already does cpumask_first(), so it has a strong > leftmost preference. We just need to make sure it indeed does the right > thing and doesn't have some unintended side effect. > -- 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/
