Re: [PATCH] drm/virtio: fix vq wait_event condition
On 20 April 2018 at 17:22, Gerd Hoffmann wrote:
> On Tue, Apr 03, 2018 at 11:59:04AM +0200, Gerd Hoffmann wrote:
>> Wait until we have enough space in the virt queue to actually queue up
>> our request. Avoids the guest spinning in case we have a non-zero
>> amount of free entries but not enough for the request.
>
> Ping airlied, can you please either pick it up or review so I can commit
> myself?
Just in case it got lost from my phone,
Reviewed-by: Dave Airlie
>
> thanks,
> Gerd
>
>> Cc: sta...@vger.kernel.org
>> Reported-by: Alain Magloire
>> Signed-off-by: Gerd Hoffmann
>> ---
>> drivers/gpu/drm/virtio/virtgpu_vq.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c
>> b/drivers/gpu/drm/virtio/virtgpu_vq.c
>> index 48e4f1df6e..020070d483 100644
>> --- a/drivers/gpu/drm/virtio/virtgpu_vq.c
>> +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
>> @@ -293,7 +293,7 @@ static int virtio_gpu_queue_ctrl_buffer_locked(struct
>> virtio_gpu_device *vgdev,
>> ret = virtqueue_add_sgs(vq, sgs, outcnt, incnt, vbuf, GFP_ATOMIC);
>> if (ret == -ENOSPC) {
>> spin_unlock(&vgdev->ctrlq.qlock);
>> - wait_event(vgdev->ctrlq.ack_queue, vq->num_free);
>> + wait_event(vgdev->ctrlq.ack_queue, vq->num_free >= outcnt +
>> incnt);
>> spin_lock(&vgdev->ctrlq.qlock);
>> goto retry;
>> } else {
>> @@ -368,7 +368,7 @@ static int virtio_gpu_queue_cursor(struct
>> virtio_gpu_device *vgdev,
>> ret = virtqueue_add_sgs(vq, sgs, outcnt, 0, vbuf, GFP_ATOMIC);
>> if (ret == -ENOSPC) {
>> spin_unlock(&vgdev->cursorq.qlock);
>> - wait_event(vgdev->cursorq.ack_queue, vq->num_free);
>> + wait_event(vgdev->cursorq.ack_queue, vq->num_free >= outcnt);
>> spin_lock(&vgdev->cursorq.qlock);
>> goto retry;
>> } else {
>> --
>> 2.9.3
>>
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Re: [PATCH] drm/virtio: fix vq wait_event condition
Reviewed-by: Dave Airlie
On Fri., 20 Apr. 2018, 17:23 Gerd Hoffmann, wrote:
> On Tue, Apr 03, 2018 at 11:59:04AM +0200, Gerd Hoffmann wrote:
> > Wait until we have enough space in the virt queue to actually queue up
> > our request. Avoids the guest spinning in case we have a non-zero
> > amount of free entries but not enough for the request.
>
> Ping airlied, can you please either pick it up or review so I can commit
> myself?
>
> thanks,
> Gerd
>
> > Cc: sta...@vger.kernel.org
> > Reported-by: Alain Magloire
> > Signed-off-by: Gerd Hoffmann
> > ---
> > drivers/gpu/drm/virtio/virtgpu_vq.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c
> b/drivers/gpu/drm/virtio/virtgpu_vq.c
> > index 48e4f1df6e..020070d483 100644
> > --- a/drivers/gpu/drm/virtio/virtgpu_vq.c
> > +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
> > @@ -293,7 +293,7 @@ static int
> virtio_gpu_queue_ctrl_buffer_locked(struct virtio_gpu_device *vgdev,
> > ret = virtqueue_add_sgs(vq, sgs, outcnt, incnt, vbuf, GFP_ATOMIC);
> > if (ret == -ENOSPC) {
> > spin_unlock(&vgdev->ctrlq.qlock);
> > - wait_event(vgdev->ctrlq.ack_queue, vq->num_free);
> > + wait_event(vgdev->ctrlq.ack_queue, vq->num_free >= outcnt
> + incnt);
> > spin_lock(&vgdev->ctrlq.qlock);
> > goto retry;
> > } else {
> > @@ -368,7 +368,7 @@ static int virtio_gpu_queue_cursor(struct
> virtio_gpu_device *vgdev,
> > ret = virtqueue_add_sgs(vq, sgs, outcnt, 0, vbuf, GFP_ATOMIC);
> > if (ret == -ENOSPC) {
> > spin_unlock(&vgdev->cursorq.qlock);
> > - wait_event(vgdev->cursorq.ack_queue, vq->num_free);
> > + wait_event(vgdev->cursorq.ack_queue, vq->num_free >=
> outcnt);
> > spin_lock(&vgdev->cursorq.qlock);
> > goto retry;
> > } else {
> > --
> > 2.9.3
> >
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Re: [PATCH] drm/virtio: fix vq wait_event condition
On Tue, Apr 03, 2018 at 11:59:04AM +0200, Gerd Hoffmann wrote:
> Wait until we have enough space in the virt queue to actually queue up
> our request. Avoids the guest spinning in case we have a non-zero
> amount of free entries but not enough for the request.
Ping airlied, can you please either pick it up or review so I can commit
myself?
thanks,
Gerd
> Cc: sta...@vger.kernel.org
> Reported-by: Alain Magloire
> Signed-off-by: Gerd Hoffmann
> ---
> drivers/gpu/drm/virtio/virtgpu_vq.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c
> b/drivers/gpu/drm/virtio/virtgpu_vq.c
> index 48e4f1df6e..020070d483 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_vq.c
> +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
> @@ -293,7 +293,7 @@ static int virtio_gpu_queue_ctrl_buffer_locked(struct
> virtio_gpu_device *vgdev,
> ret = virtqueue_add_sgs(vq, sgs, outcnt, incnt, vbuf, GFP_ATOMIC);
> if (ret == -ENOSPC) {
> spin_unlock(&vgdev->ctrlq.qlock);
> - wait_event(vgdev->ctrlq.ack_queue, vq->num_free);
> + wait_event(vgdev->ctrlq.ack_queue, vq->num_free >= outcnt +
> incnt);
> spin_lock(&vgdev->ctrlq.qlock);
> goto retry;
> } else {
> @@ -368,7 +368,7 @@ static int virtio_gpu_queue_cursor(struct
> virtio_gpu_device *vgdev,
> ret = virtqueue_add_sgs(vq, sgs, outcnt, 0, vbuf, GFP_ATOMIC);
> if (ret == -ENOSPC) {
> spin_unlock(&vgdev->cursorq.qlock);
> - wait_event(vgdev->cursorq.ack_queue, vq->num_free);
> + wait_event(vgdev->cursorq.ack_queue, vq->num_free >= outcnt);
> spin_lock(&vgdev->cursorq.qlock);
> goto retry;
> } else {
> --
> 2.9.3
>
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