On 03/21/2013 02:57 PM, Alex Shi wrote: > On 03/21/2013 04:41 PM, Preeti U Murthy wrote: >>>> >> Yes, I did find this behaviour on a 2 socket, 8 core machine very >> consistently. >> >> rq->util cannot go to 0, after it has begun accumulating load right? >> >> Say a load was running on a runqueue which had its rq->util to be at >> 100%. After the load finishes, the runqueue goes idle. For every >> scheduler tick, its utilisation decays. But can never become 0. >> >> rq->util = rq->avg.runnable_avg_sum/rq->avg.runnable_avg_period > > > did you close all of background system services? > In theory the rq->avg.runnable_avg_sum should be zero if there is no > task a bit long, otherwise there are some bugs in kernel.
Could you explain why rq->avg.runnable_avg_sum should be zero? What if some kernel thread ran on this run queue and is now finished? Its utilisation would be say x.How would that ever drop to 0,even if nothing ran on it later? Regards Preeti U Murthy Could you > check the value under /proc/sched_debug? > > -- 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/
