On Wed, 09 Jan 2013 16:34:39 +0800, Alex Shi wrote: > On 01/09/2013 03:54 PM, Namhyung Kim wrote: >> Hi Alex, >> >> On Wed, 09 Jan 2013 15:33:40 +0800, Alex Shi wrote: >>> On 01/09/2013 02:50 PM, Namhyung Kim wrote: >>>> From: Namhyung Kim <namhyung....@lge.com> >>>> >>>> AFAICS @target cpu of select_idle_sibling() is always either prev_cpu >>>> or this_cpu. So no need to check it again and the conditionals can be >>>> consolidated. >> [snip] >>> Uh, we don't know if the target is this_cpu or previous cpu, If we just >>> check the target idle status, we may miss another idle cpu. So this >>> patch change the logical in this function. >> >> select_idle_sibling() is called only in select_task_rq_fair() if it >> found a suitable affine_sd. The default target is the 'prev_cpu' of the >> task but if wake_affine() returns true it'd be (this) 'cpu'. >> >> I cannot see where the prev_cpu or the cpu is set to another one before >> calling select_idle_sibling. > > The old logical will return directly whenever prev_cpu or this cpu idle, > but your new logical just has one chance.
Sorry, I can't get your point. Could you elaborate on it a bit more? Thanks, Namhyung -- 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/
