search for: virtqueue_enable_cb_delay

On 10/15/2014 05:34 PM, Michael S. Tsirkin wrote: > On Wed, Oct 15, 2014 at 03:25:25PM +0800, Jason Wang wrote: >> This patch checks the new event idx to make sure used event idx never >> goes back. This is used to synchronize the calls between >> virtqueue_enable_cb_delayed() and virtqueue_enable_cb(). >> >> Cc: Rusty Russell <rusty at rustcorp.com.au> >> Cc: Michael S. Tsirkin <mst at redhat.com> >> Signed-off-by: Jason Wang <jasowang at redhat.com> > the implication being that moving event idx back might cause some race...

On 10/15/2014 05:34 PM, Michael S. Tsirkin wrote: > On Wed, Oct 15, 2014 at 03:25:25PM +0800, Jason Wang wrote: >> This patch checks the new event idx to make sure used event idx never >> goes back. This is used to synchronize the calls between >> virtqueue_enable_cb_delayed() and virtqueue_enable_cb(). >> >> Cc: Rusty Russell <rusty at rustcorp.com.au> >> Cc: Michael S. Tsirkin <mst at redhat.com> >> Signed-off-by: Jason Wang <jasowang at redhat.com> > the implication being that moving event idx back might cause some race...

...n 10/15/2014 05:34 PM, Michael S. Tsirkin wrote: >>> On Wed, Oct 15, 2014 at 03:25:25PM +0800, Jason Wang wrote: >>>> This patch checks the new event idx to make sure used event idx never >>>> goes back. This is used to synchronize the calls between >>>> virtqueue_enable_cb_delayed() and virtqueue_enable_cb(). >>>> >>>> Cc: Rusty Russell <rusty at rustcorp.com.au> >>>> Cc: Michael S. Tsirkin <mst at redhat.com> >>>> Signed-off-by: Jason Wang <jasowang at redhat.com> >>> the implication being that mov...

...n 10/15/2014 05:34 PM, Michael S. Tsirkin wrote: >>> On Wed, Oct 15, 2014 at 03:25:25PM +0800, Jason Wang wrote: >>>> This patch checks the new event idx to make sure used event idx never >>>> goes back. This is used to synchronize the calls between >>>> virtqueue_enable_cb_delayed() and virtqueue_enable_cb(). >>>> >>>> Cc: Rusty Russell <rusty at rustcorp.com.au> >>>> Cc: Michael S. Tsirkin <mst at redhat.com> >>>> Signed-off-by: Jason Wang <jasowang at redhat.com> >>> the implication being that mov...

...rote: > On 10/15/2014 05:34 PM, Michael S. Tsirkin wrote: > > On Wed, Oct 15, 2014 at 03:25:25PM +0800, Jason Wang wrote: > >> This patch checks the new event idx to make sure used event idx never > >> goes back. This is used to synchronize the calls between > >> virtqueue_enable_cb_delayed() and virtqueue_enable_cb(). > >> > >> Cc: Rusty Russell <rusty at rustcorp.com.au> > >> Cc: Michael S. Tsirkin <mst at redhat.com> > >> Signed-off-by: Jason Wang <jasowang at redhat.com> > > the implication being that moving event idx b...

...not one. I mildly prefer to avoid the branch, by changing the calculation like so: /* Set bufs >= 1, even if there's only one pending buffer */ bufs = (bufs + 1) * 3 / 4; But it's not clear to me how much this happens. I'm happy with the patch though, as currently virtqueue_enable_cb_delayed() is the same as virtqueue_enable_cb() if there's only been one buffer added. Cheers, Rusty. > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/virtio/virtio_ring.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/driver...

...not one. I mildly prefer to avoid the branch, by changing the calculation like so: /* Set bufs >= 1, even if there's only one pending buffer */ bufs = (bufs + 1) * 3 / 4; But it's not clear to me how much this happens. I'm happy with the patch though, as currently virtqueue_enable_cb_delayed() is the same as virtqueue_enable_cb() if there's only been one buffer added. Cheers, Rusty. > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/virtio/virtio_ring.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/driver...

This patch checks the new event idx to make sure used event idx never goes back. This is used to synchronize the calls between virtqueue_enable_cb_delayed() and virtqueue_enable_cb(). Cc: Rusty Russell <rusty at rustcorp.com.au> Cc: Michael S. Tsirkin <mst at redhat.com> Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/virtio/virtio_ring.c | 7 +++++-- 1 files changed, 5 insertions(+), 2 deletions(-) diff --git...

This patch checks the new event idx to make sure used event idx never goes back. This is used to synchronize the calls between virtqueue_enable_cb_delayed() and virtqueue_enable_cb(). Cc: Rusty Russell <rusty at rustcorp.com.au> Cc: Michael S. Tsirkin <mst at redhat.com> Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/virtio/virtio_ring.c | 7 +++++-- 1 files changed, 5 insertions(+), 2 deletions(-) diff --git...

...M, Michael S. Tsirkin wrote: > >>> On Wed, Oct 15, 2014 at 03:25:25PM +0800, Jason Wang wrote: > >>>> This patch checks the new event idx to make sure used event idx never > >>>> goes back. This is used to synchronize the calls between > >>>> virtqueue_enable_cb_delayed() and virtqueue_enable_cb(). > >>>> > >>>> Cc: Rusty Russell <rusty at rustcorp.com.au> > >>>> Cc: Michael S. Tsirkin <mst at redhat.com> > >>>> Signed-off-by: Jason Wang <jasowang at redhat.com> > >>> the i...

...> * >> >> * This re-enables callbacks but hints to the other side to >> delay >> * interrupts all of the available buffers have been processed; > > So this is like virtqueue_enable_cb_delayed but even more > aggressive? > I think it's too agressive: it's better to wake up guest > after you are through most of buffers, but not all, > so guest and host can work in parallel. Note that: - it was only used when there are still few of free slots (which is greater than...

...> * >> >> * This re-enables callbacks but hints to the other side to >> delay >> * interrupts all of the available buffers have been processed; > > So this is like virtqueue_enable_cb_delayed but even more > aggressive? > I think it's too agressive: it's better to wake up guest > after you are through most of buffers, but not all, > so guest and host can work in parallel. Note that: - it was only used when there are still few of free slots (which is greater than...

...capacity = 10; //########## test code : force to call netif_stop_queue > > if (capacity < 2+MAX_SKB_FRAGS) { > netif_stop_queue(dev); So you changed code to make it think we are out of capacity, now it stops the queue. > > if (unlikely(!virtqueue_enable_cb_delayed(vi->svq))) { > /* More just got used, free them then recheck. */ > capacity += free_old_xmit_skbs(vi); > dev_warn(&dev->dev, "free_old_xmit_skbs capacity =%d MAX_SKB_FRAGS=%d", capacity, MAX_SKB_F...

...capacity = 10; //########## test code : force to call netif_stop_queue > > if (capacity < 2+MAX_SKB_FRAGS) { > netif_stop_queue(dev); So you changed code to make it think we are out of capacity, now it stops the queue. > > if (unlikely(!virtqueue_enable_cb_delayed(vi->svq))) { > /* More just got used, free them then recheck. */ > capacity += free_old_xmit_skbs(vi); > dev_warn(&dev->dev, "free_old_xmit_skbs capacity =%d MAX_SKB_FRAGS=%d", capacity, MAX_SKB_F...

...nsigned int bytes = skb->len; > + bool kick; > > /* Free up any pending old buffers before queueing new ones. */ > - free_old_xmit_skbs(sq); > + free_old_xmit_skbs(sq, txq, use_napi); > > - if (use_napi && kick) > + if (use_napi && !more) > virtqueue_enable_cb_delayed(sq->vq); > > /* timestamp packet in software */ > @@ -1552,7 +1558,7 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) > if (!use_napi && > unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { > /* More just got used,...

...nsigned int bytes = skb->len; > + bool kick; > > /* Free up any pending old buffers before queueing new ones. */ > - free_old_xmit_skbs(sq); > + free_old_xmit_skbs(sq, txq, use_napi); > > - if (use_napi && kick) > + if (use_napi && !more) > virtqueue_enable_cb_delayed(sq->vq); > > /* timestamp packet in software */ > @@ -1552,7 +1558,7 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) > if (!use_napi && > unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { > /* More just got used,...

Fix some signed/assigned mistakes in virtqueue_enable_cb_delayed by using u16 math all over. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- I'll put this on my v1 branch as well @@ -398,7 +397,7 @@ EXPORT_SYMBOL_GPL(virtqueue_enable_cb); bool virtqueue_enable_cb_delayed(struct virtqueue *_vq) { struct vring_virtqueue *vq = to_vvq(_...

Fix some signed/assigned mistakes in virtqueue_enable_cb_delayed by using u16 math all over. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- I'll put this on my v1 branch as well @@ -398,7 +397,7 @@ EXPORT_SYMBOL_GPL(virtqueue_enable_cb); bool virtqueue_enable_cb_delayed(struct virtqueue *_vq) { struct vring_virtqueue *vq = to_vvq(_...

...static int virtnet_poll_tx(struct napi_struct *napi, int budget) again: __netif_tx_lock(txq, smp_processor_id()); virtqueue_disable_cb(sq->vq); - sent += free_old_xmit_skbs(sq, budget - sent); + sent += free_old_xmit_skbs(txq, sq, budget - sent); if (sent < budget) { enable_done = virtqueue_enable_cb_delayed(sq->vq); @@ -962,12 +967,13 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum); bool kick = !skb->xmit_more; bool stopped; + unsigned int bytes = skb->len; virtqueue_disable_cb(sq->vq);...

...virtqueue_enable_cb(struct virtqueue *vq); >> >> unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq); >> >> +bool virtqueue_enable_cb_avail(struct virtqueue *vq); >> + >> bool virtqueue_poll(struct virtqueue *vq, unsigned); >> >> bool virtqueue_enable_cb_delayed(struct virtqueue *vq); >> -- >> 1.7.1 > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo at vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read...