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 <[email protected]> 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? > > On 4 April 2016 at 19:17, Okky Hendriansyah <[email protected]> wrote: > >> On Mon, Apr 4, 2016 at 8:20 AM, Jayme Howard <[email protected]> wrote: >> >>> Okay wow, Alex. That made a huge difference immediately. That dropped >>> me from 90% to 33% on the main thread, and all the children are below 10%. >>> >> >>> On Sun, Apr 3, 2016 at 8:07 PM, Alex Williamson < >>> [email protected]> wrote: >>> >>>> If this is the issue I think it is, the unraid folks bisected this and >>>> found the culprit as: >>>> >>>> aca6ff2 KVM: dynamic halt-polling >>>> >>>> ( >>>> https://github.com/torvalds/linux/commit/aca6ff29c4063a8d467cdee241e6b3bf7dc4a171 >>>> ) >>>> >>>> It seems to be a poor interaction of the halt polling interval vs the >>>> timer ticks on win10. You can pick a different polling interval with the >>>> kvm module option halt_poll_ns. The default is 500000. It seemed that >>>> setting this to 400000 or lower resolves the issue. You can do this via a >>>> modprobe entry, 'options kvm halt_poll_ns=400000' or on the kernel command >>>> line with kvm.halt_poll_ns=400000. You can also change it dynamically via >>>> 'echo 400000 > /sys/module/kvm/parameters/halt_poll_ns' >>>> >>> >> I can also confirm that tuning the halt_poll_ns kvm module parameter on >> kernel 4.4.5 drops the host CPU usage! Haven't done any game benchmark but >> from listening to music the CPU load is as low as it is on 4.1.20. Although >> reducing the value to what Alex (400000) had suggested is probably >> sufficient, I'm currently trying out the value of 0 for it just like what >> Unraid 6.20 beta 20 changelog had it set on default [1]. Thanks for the >> info, Alex. >> >> [1] >> http://dnld.lime-technology.com/beta/unRAIDServer-6.2.0-beta20-x86_64.txt >> >> >> Best regards, >> Okky Hendriansyah >> >> _______________________________________________ >> vfio-users mailing list >> [email protected] >> https://www.redhat.com/mailman/listinfo/vfio-users >> >> > > _______________________________________________ > vfio-users mailing list > [email protected] > https://www.redhat.com/mailman/listinfo/vfio-users > >
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