Re: I/O scheduler deadlocks on Xen virtual block devices

From: Jeff Moyer
Date: Thu Sep 02 2010 - 09:49:31 EST


Doug Neal <dneallkml@xxxxxxxxx> writes:

>>
>> Did you try these different I/O schedulers in the domU or on the dom0?
>> Does switching I/O schedulers in either place make the problem go away
>> when it happens?
>>
>
> In the domU, and the bug was present in all cases. The dom0 was using
> cfq. I'll run the tests again using each scheduler in the dom0 with
> domU set to noop and report back.

While I think this is an interesting test, you need only test one I/O
scheduler in the dom0. Also, I think you misunderstood the second
question. I'd like to know if switching I/O schedulers while the system
is in this bad state helps get I/O going again.

Cheers,
Jeff
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