Messages in this thread | | | Date | Fri, 20 Jan 2012 21:56:08 -0800 | Subject | Re: x86, mce, Use user return notifier in mce | From | Tejun Heo <> |
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Hello,
On Fri, Jan 20, 2012 at 6:44 PM, Huang Ying <ying.huang@intel.com> wrote: > It appears that WQ_HIGHPRI only provides priority between work queue, > not between the work queue backing kthread and other tasks. Is there > any mechanism for that?
No, it doesn't.
> If my understanding was correct, WQ_MEM_RECLAIM has some side-effect for > that. Because hardware errors occurs seldom, the reserved kthread for > WQ_MEME_RECLAIM just sleeps most of the time. When first hardware error > occurs and the work item is queued, the reserved kthread is waked up. > Because the reserved kthread sleeps for long time, it is highly possible > for it to be scheduled at the next schedule point.
But rescuer is used only under memory pressure. It doesn't help latency at all.
> Because hardware error usually has no locality, WQ_UNBOUND can be used > for it so that the work item can be put on relative low-load CPU. From > the document, it is said WQ_UNBOUND work items will be executed ASAP > too. Compared with WQ_HIGHPRI, how about the priority of WQ_UNBOUND?
Maybe, maybe not. I suggest just using WQ_HIGHPRI for now and worrying about it later if the scheduling latency actually turns out to matter.
Thanks.
-- tejun -- 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/
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