[vfio-users] Stutter in games

[Okky Hendriansyah]

On Mon, Jan 23, 2017 at 11:48 PM, Tiit Talts <itvend at gmail.com> wrote:

> QEMU 2.8+
> Kernel 4.8 @ Debian 8
>
> Guest OS: Windows 10
>
> H/W: CPU: AMD FX-8300, MB: GA-990XA-UD3, GPU: GTX 1080
>
> FPS in games are great 150+/- @ normal details, but i have periodic fps
> drops from 150 to 30-20fps when i move in game. i noticed that when i stand
> still in Battlefield 4 no fps drops everything is fine but if is start
> moving i get fps drops.
>
> Other info:
>
>
> perf kvm --host stat live
> When gaming most VM-Exits are msr and interrupt
>
>
> GRUB:
>
> BOOT_IMAGE=/vmlinuz-4.8.0-0.bpo.2-amd64 root=/dev/mapper/debian--vg-root
> ro iommu=pt amd_iommu=on
>
> /etc/modprobe.d/kvm.conf
>
> options kvm              ignore_msrs=1
> options kvm_amd          npt=0
>
> /etc/modules
>
> kvm
> kvm_amd
> vfio
> vfio_iommu_type1
> vfio_pci
> vfio_virqfd
>
> Any advice, quit VM or burn down AMD platform ?
>
>
Hi Tiit,

Any chance that your kernel flags for your clock resolution is not high
enough? What about your pre-emption scheduling? I found my clock resolution
set to 1000 Hz and voluntary pre-emption scheduling fully eliminates
stutters in Witcher 3.

Best regards,
Okky
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/vfio-users/attachments/20170124/06868484/attachment.htm>