Re: Poor windows VFIO performance, GPU stalls (bisected)

From: Chris Wilson
Date: Sun Jul 26 2020 - 10:16:07 EST


Quoting Alex Williamson (2020-07-26 14:30:52)
> On Sun, 26 Jul 2020 17:49:07 +1000
> Geoffrey McRae <geoff@xxxxxxxxxxxxxxx> wrote:
>
> > Hi All,
> >
> > The commit 22540ca3d00d2990a4148a13b92209c3dc5422db causes a Windows KVM
> > guest running under QEMU with a VFIO passthrough GPU to randomly stall
> > when using the GPU leading to the guest assuming that the driver has
> > hung. Reverting this commit resolves the problem.
>
> Please double check this commit ID, I can't find it in mainline or
> linux-next. Thanks,

See commit aa202f1f5696 ("workqueue: don't use wq_select_unbound_cpu()
for bound works"). 22540ca3 is the cherry-pick into v5.4.26
-Chris