[vfio-users] cpu usage in guest != cpu usage in host, even with exclusive pinning

Okky Hendriansyah okky.htf at gmail.com
Fri Apr 29 00:20:45 UTC 2016


On Tue, Apr 5, 2016 at 6:31 PM, Quentin Deldycke <quentindeldycke at gmail.com>
wrote:

> I tried a few with unigine valley and cinebench benchmark.
>
> Totally no difference on scores, no dpc latency difference also.
>
> But it is effective for turbostat when pc is in idle:
>
> at default value turbostat reports ~35w (cores of vm all time around
> 1.5ghz)
> at 0 turbostat report 20w (cores of vm around 300-400 mhz (6% busy)
>
> Did not try "real gaming" for the moment. Did this remotely...
>
> --
> Deldycke Quentin
>
>
> On 5 April 2016 at 10:53, Jonathan Scruggs <j.scruggs at gmail.com> wrote:
>
>> I don't know what halt_poll_ns does, but wouldn't setting it to 0
>> disable it and is disabling it bad?
>>
>> So, what does halt_poll_ns do anyways?
>>
>
Kernel 4.5.2 [1] addresses this issue and reduces the default value for
halt_poll_ns. I haven't compiled the kernel yet, but it should be the
safest value I suppose.

[1] https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.5.2

Best regards,
Okky Hendriansyah
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