On 12/07/2012 09:02 AM, Frederic Weisbecker wrote: > 2012/12/7 Alex Shi <alex....@intel.com>: >> On 12/07/2012 01:50 AM, Frederic Weisbecker wrote: >>> 2012/12/3 Alex Shi <alex....@intel.com>: >>>> It is impossible to miss a task allowed cpu in a eligible group. >>>> >>>> And since find_idlest_group only return a different group which >>>> excludes old cpu, it's also imporissible to find a new cpu same as old >>>> cpu. >>> >>> Is it possible for weighted_cpuload() to return ULONG_MAX? If so, >>> find_idlest_cpu() can return -1. >>> >> >> No, non of sched entity can has a ULONG_MAX weight. > > Ok. find_idlest_cpu() can still return -1 but select_task_rq_fair() is > the only caller. Presumably safe but code evolves. May be add some > comment to explain why what you're doing is safe. May be a > WARN_ON_ONCE() could be good to add? >
why you think it is possible to be -1? And there is a WARN_ON_ONCE for cpu = -1 in find_idlest_group when checking local_group. Thanks! -- 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/
