Messages in this thread | ![/](/images/icornerl.gif) | | Date | Tue, 20 Dec 2011 11:09:46 -0800 | From | Tejun Heo <> | Subject | Re: [PATCH RFC] virtio_net: fix refill related races |
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Hello, Michael.
On Tue, Dec 20, 2011 at 09:09:08PM +0200, Michael S. Tsirkin wrote: > Another question, wanted to make sure: > virtnet_poll does schedule_delayed_work(&vi->refill, 0); > separately refill work itself also does > schedule_delayed_work(&vi->refill, HZ/2); > If two such events happen twice, on different CPUs, we are still guaranteed > the work will only run once, right?
No, it's not. Normal workqueues only guarantee non-reentrance on local CPU. If you want to guarantee that only one instance of a given item is executing across all CPUs, you need to use the nrt workqueue.
Thanks.
-- tejun
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