Messages in this thread | | | Date | Thu, 20 Jan 2011 13:32:12 +0800 | Subject | Re: Bug in scheduler when using rt_mutex | From | Yong Zhang <> |
| |
On Thu, Jan 20, 2011 at 12:27 PM, Yong Zhang <yong.zhang0@gmail.com> wrote: > on Thu, Jan 20, 2011 at 12:18 PM, Yong Zhang <yong.zhang0@gmail.com> wrote: >> On Wed, Jan 19, 2011 at 9:30 PM, Peter Zijlstra <peterz@infradead.org> wrote: >>> +static void switched_from_fair(struct rq *rq, struct task_struct *p) >>> +{ >>> + struct sched_entity *se = &p->se; >>> + struct cfs_rq *cfs_rq = cfs_rq_of(se); >>> + >>> + /* >>> + * Ensure the task's vruntime is normalized, so that when its >>> + * switched back to the fair class the enqueue_entity(.flags=0) will >>> + * do the right thing. >>> + * >>> + * If it was on_rq, then the dequeue_entity(.flags=0) will already >>> + * have normalized the vruntime, if it was !on_rq, then only when >>> + * the task is sleeping will it still have non-normalized vruntime. >>> + */ >>> + if (!se->on_rq && p->state != TASK_RUNNING) >>> + se->vruntime -= cfs_rq->min_vruntime; >> >> Here it's possible that se->vruntime is little than cfs_rq->min_vruntime. > > Maybe we can: > place_entity(cfs_rq, se, 0); > se->vruntime -= cfs_rq->min_vruntime;
Hmmm, this doesn't make sense since we don't know how long the task will sleep after we do this. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |