On 2016/07/11 at 16:22, Xunlei Pang wrote: > On 2016/07/11 at 15:25, Wanpeng Li wrote: >> 2016-06-16 20:57 GMT+08:00 Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>: >>> Hierarchy could be already throttled at this point. Throttled next >>> buddy could trigger null pointer dereference in pick_next_task_fair(). >> There is cfs_rq->next check in pick_next_entity(), so how can null >> pointer dereference happen? > I guess it's the following code leading to a NULL se returned: s/NULL/empty-entity cfs_rq se/ > pick_next_entity(): > if (cfs_rq->next && wakeup_preempt_entity(cfs_rq->next, left) < 1) > se = cfs_rq->next; > > Regards, > Xunlei > >> Regards, >> Wanpeng Li -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html