Re: [Qemu-devel] virtio-scsi-pci iothread spins at 100%

2017-02-09 Thread Fam Zheng
On Thu, 02/09 05:52, Ed Swierk wrote: > On Thu, Feb 9, 2017 at 2:12 AM, Fam Zheng wrote: > > This should fix it: > > > > https://lists.gnu.org/archive/html/qemu-devel/2017-02/msg01874.html > > I tested this patch and found it fixes the problem. Thanks for the > speedy response!

Re: [Qemu-devel] virtio-scsi-pci iothread spins at 100%

2017-02-09 Thread Ed Swierk
On Thu, Feb 9, 2017 at 2:12 AM, Fam Zheng wrote: > This should fix it: > > https://lists.gnu.org/archive/html/qemu-devel/2017-02/msg01874.html I tested this patch and found it fixes the problem. Thanks for the speedy response! --Ed

Re: [Qemu-devel] virtio-scsi-pci iothread spins at 100%

2017-02-09 Thread Fam Zheng
On Wed, 02/08 19:44, Ed Swierk wrote: > On Wed, Feb 8, 2017 at 6:52 PM, Fam Zheng wrote: > > This means virtio-scsi event vq handler is returning true but actually no > > progress is made. Can you try the following patch to see if it's because a > > stalled cache of VQ index? > >

Re: [Qemu-devel] virtio-scsi-pci iothread spins at 100%

2017-02-08 Thread Fam Zheng
On Thu, 02/09 13:39, Fam Zheng wrote: > On Wed, 02/08 19:44, Ed Swierk wrote: > > On Wed, Feb 8, 2017 at 6:52 PM, Fam Zheng wrote: > > > This means virtio-scsi event vq handler is returning true but actually no > > > progress is made. Can you try the following patch to see if

Re: [Qemu-devel] virtio-scsi-pci iothread spins at 100%

2017-02-08 Thread Fam Zheng
On Wed, 02/08 19:44, Ed Swierk wrote: > On Wed, Feb 8, 2017 at 6:52 PM, Fam Zheng wrote: > > This means virtio-scsi event vq handler is returning true but actually no > > progress is made. Can you try the following patch to see if it's because a > > stalled cache of VQ index? > >

Re: [Qemu-devel] virtio-scsi-pci iothread spins at 100%

2017-02-08 Thread Ed Swierk
On Wed, Feb 8, 2017 at 6:52 PM, Fam Zheng wrote: > This means virtio-scsi event vq handler is returning true but actually no > progress is made. Can you try the following patch to see if it's because a > stalled cache of VQ index? > > diff --git a/hw/virtio/virtio.c

Re: [Qemu-devel] virtio-scsi-pci iothread spins at 100%

2017-02-08 Thread Fam Zheng
On Wed, 02/08 18:11, Ed Swierk wrote: > On Wed, Feb 8, 2017 at 5:47 PM, Fam Zheng wrote: > > No, something is wrong. The polling shouldn't keep running when there is no > > I/O > > activity. > > > > Can you try "perf top" to see what poll handlers are spinning? > > Samples:

Re: [Qemu-devel] virtio-scsi-pci iothread spins at 100%

2017-02-08 Thread Ed Swierk
On Wed, Feb 8, 2017 at 5:47 PM, Fam Zheng wrote: > No, something is wrong. The polling shouldn't keep running when there is no > I/O > activity. > > Can you try "perf top" to see what poll handlers are spinning? Samples: 288K of event 'cycles', Event count (approx.):

Re: [Qemu-devel] virtio-scsi-pci iothread spins at 100%

2017-02-08 Thread Fam Zheng
On Wed, 02/08 08:33, Ed Swierk wrote: > Recently I noticed that when I configure a virtio-scsi-pci device > using an iothread, as soon as the guest virtio-scsi driver loads, the > iothread spins at 100%: > > -object iothread,id=iothread1 -device virtio-scsi-pci,iothread=iothread1 > > This

Re: [Qemu-devel] virtio-scsi-pci iothread spins at 100%

2017-02-08 Thread Ed Swierk
On Wed, Feb 8, 2017 at 8:33 AM, Ed Swierk wrote: > Recently I noticed that when I configure a virtio-scsi-pci device > using an iothread, as soon as the guest virtio-scsi driver loads, the > iothread spins at 100%: > > -object iothread,id=iothread1 -device