Re: Poor windows VFIO performance, GPU stalls (bisected)
Quoting Alex Williamson (2020-07-26 14:30:52)
> On Sun, 26 Jul 2020 17:49:07 +1000
> Geoffrey McRae 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
Re: Poor windows VFIO performance, GPU stalls (bisected)
On 2020-07-26 23:32, Geoffrey McRae wrote: On 2020-07-26 23:30, Alex Williamson wrote: On Sun, 26 Jul 2020 17:49:07 +1000 Geoffrey McRae 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, Alex Confirmed: https://github.com/torvalds/linux/commit/22540ca3d00d2990a4148a13b92209c3dc5422db Sorry, I just noticed my error, it should be: aa202f1f56960c60e7befaa0f49c72b8fa11b0a8 The host system is configured with the following kernel arguments which may be related: isolcpus=0-5,24-29,6-11,30-35 rcu_nocbs=0-5,24-29,6-11,30-35 The system is an AMD Threadripper 2970WX on a Gigabyte x399 AORUS Gaming 7 board. It has two GPUs each being passed through to two separate KVM guests, one is an AMD Radeon 7 in a Linux guest, the other is a GeForce 1080Ti in a Windows guest. The cores used for these two guests are isolated from the host for performance reasons. Any insight as to why this is occurring would be appreciated. If you need any more information or would like to test patches please let me know. Kind Regards, Geoffrey McRae HostFission https://hostfission.com
Re: Poor windows VFIO performance, GPU stalls (bisected)
On 2020-07-26 23:30, Alex Williamson wrote: On Sun, 26 Jul 2020 17:49:07 +1000 Geoffrey McRae 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, Alex Confirmed: https://github.com/torvalds/linux/commit/22540ca3d00d2990a4148a13b92209c3dc5422db The host system is configured with the following kernel arguments which may be related: isolcpus=0-5,24-29,6-11,30-35 rcu_nocbs=0-5,24-29,6-11,30-35 The system is an AMD Threadripper 2970WX on a Gigabyte x399 AORUS Gaming 7 board. It has two GPUs each being passed through to two separate KVM guests, one is an AMD Radeon 7 in a Linux guest, the other is a GeForce 1080Ti in a Windows guest. The cores used for these two guests are isolated from the host for performance reasons. Any insight as to why this is occurring would be appreciated. If you need any more information or would like to test patches please let me know. Kind Regards, Geoffrey McRae HostFission https://hostfission.com
Re: Poor windows VFIO performance, GPU stalls (bisected)
On Sun, 26 Jul 2020 17:49:07 +1000 Geoffrey McRae 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, Alex > The host system is configured with the following kernel arguments which > may be related: >isolcpus=0-5,24-29,6-11,30-35 rcu_nocbs=0-5,24-29,6-11,30-35 > > The system is an AMD Threadripper 2970WX on a Gigabyte x399 AORUS Gaming > 7 board. > It has two GPUs each being passed through to two separate KVM guests, > one is an AMD Radeon 7 in a Linux guest, the other is a GeForce 1080Ti > in a Windows guest. > The cores used for these two guests are isolated from the host for > performance reasons. > > Any insight as to why this is occurring would be appreciated. If you > need any more information or would like to test patches please let me > know. > > Kind Regards, > Geoffrey McRae > HostFission > > https://hostfission.com >
Poor windows VFIO performance, GPU stalls (bisected)
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. The host system is configured with the following kernel arguments which may be related: isolcpus=0-5,24-29,6-11,30-35 rcu_nocbs=0-5,24-29,6-11,30-35 The system is an AMD Threadripper 2970WX on a Gigabyte x399 AORUS Gaming 7 board. It has two GPUs each being passed through to two separate KVM guests, one is an AMD Radeon 7 in a Linux guest, the other is a GeForce 1080Ti in a Windows guest. The cores used for these two guests are isolated from the host for performance reasons. Any insight as to why this is occurring would be appreciated. If you need any more information or would like to test patches please let me know. Kind Regards, Geoffrey McRae HostFission https://hostfission.com
