similar to: [net-next v2] virtio_net: replace netdev_alloc_skb_ip_align() with napi_alloc_skb()

This gives small but noticeable rx performance improvement (2-3%) and will allow exploiting future napi improvement. Signed-off-by: Paolo Abeni <pabeni at redhat.com> --- drivers/net/virtio_net.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index fb0eae4..49d84e5 100644 --- a/drivers/net/virtio_net.c +++

This gives small but noticeable rx performance improvement (2-3%) and will allow exploiting future napi improvement. Signed-off-by: Paolo Abeni <pabeni at redhat.com> --- drivers/net/virtio_net.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index fb0eae4..49d84e5 100644 --- a/drivers/net/virtio_net.c +++

On Thu, Mar 17, 2016 at 7:44 AM, Paolo Abeni <pabeni at redhat.com> wrote: > > This gives small but noticeable rx performance improvement (2-3%) > and will allow exploiting future napi improvement. > > Signed-off-by: Paolo Abeni <pabeni at redhat.com> > --- Worked in my tests, though the performance win was in the noise (+0.6% - +1% bandwidth). What tests did you see

Similar to commit a2ac99905f1e ("vhost-net: set packet weight of tx polling to 2 * vq size"), we need a packet-based limit for handler_rx, too - elsewhere, under rx flood with small packets, tx can be delayed for a very long time, even without busypolling. The pkt limit applied to handle_rx must be the same applied by handle_tx, or we will get unfair scheduling between rx and tx. Tying

The following series applies to net-next. The following series changes the low memory paths in virtio_net to allow the driver to contribute to reclaim when memory is tight. It attempts to rectify some performance problems we've seen where the network performance drops significantly when memory is low. The working theory is that while the driver contributes to memory pressure when throughput

The following series applies to net-next. The following series changes the low memory paths in virtio_net to allow the driver to contribute to reclaim when memory is tight. It attempts to rectify some performance problems we've seen where the network performance drops significantly when memory is low. The working theory is that while the driver contributes to memory pressure when throughput

The virtio_net driver's mergeable receive buffer allocator uses 4KB packet buffers. For MTU-sized traffic, SKB truesize is > 4KB but only ~1500 bytes of the buffer is used to store packet data, reducing the effective TCP window size substantially. This patch addresses the performance concerns with mergeable receive buffers by allocating MTU-sized packet buffers using page frag allocators.

The virtio_net driver's mergeable receive buffer allocator uses 4KB packet buffers. For MTU-sized traffic, SKB truesize is > 4KB but only ~1500 bytes of the buffer is used to store packet data, reducing the effective TCP window size substantially. This patch addresses the performance concerns with mergeable receive buffers by allocating MTU-sized packet buffers using page frag allocators.

On Thu, 30 Mar 2023 12:48:22 +0200, Paolo Abeni <pabeni at redhat.com> wrote: > On Tue, 2023-03-28 at 20:04 +0800, Xuan Zhuo wrote: > > @@ -949,15 +1042,11 @@ static struct sk_buff *receive_small(struct net_device *dev, > > { > > struct sk_buff *skb; > > struct bpf_prog *xdp_prog; > > - unsigned int xdp_headroom = (unsigned long)ctx; > > - unsigned

Hi, On Tue, 2023-03-07 at 09:49 +0800, Xuan Zhuo wrote: > On Mon, 6 Mar 2023 12:58:22 -0500, "Michael S. Tsirkin" <mst at redhat.com> wrote: > > On Mon, Mar 06, 2023 at 12:15:33PM +0800, Xuan Zhuo wrote: > > > If the queue of xdp xmit is not an independent queue, then when the xdp > > > xmit used all the desc, the xmit from the __dev_queue_xmit() may

Commit 2613af0ed18a ("virtio_net: migrate mergeable rx buffers to page frag allocators") changed the mergeable receive buffer size from PAGE_SIZE to MTU-size. However, the merge buffer size does not take into account the size of the virtio-net header. Consequently, packets that are MTU-size will take two buffers intead of one (to store the virtio-net header), substantially decreasing the

Commit 2613af0ed18a ("virtio_net: migrate mergeable rx buffers to page frag allocators") changed the mergeable receive buffer size from PAGE_SIZE to MTU-size. However, the merge buffer size does not take into account the size of the virtio-net header. Consequently, packets that are MTU-size will take two buffers intead of one (to store the virtio-net header), substantially decreasing the

On Tue, 2023-07-25 at 16:07 +0300, Gavin Li wrote: > Add interrupt_coalesce config in send_queue and receive_queue to cache user > config. > > Send per virtqueue interrupt moderation config to underlying device in > order to have more efficient interrupt moderation and cpu utilization of > guest VM. > > Additionally, address all the VQs when updating the global

----- ???? ----- > On Wed, Nov 20, 2013 at 05:07:25PM +0800, Jason Wang wrote: > > When mergeable buffer were used, we only put the first page buf leave the > > rest > > of buffers in the virt queue. This will cause the driver could not get the > > correct head buffer any more. Fix this by dropping the rest of buffers for > > this > > packet. > > >

----- ???? ----- > On Wed, Nov 20, 2013 at 05:07:25PM +0800, Jason Wang wrote: > > When mergeable buffer were used, we only put the first page buf leave the > > rest > > of buffers in the virt queue. This will cause the driver could not get the > > correct head buffer any more. Fix this by dropping the rest of buffers for > > this > > packet. > > >

Too many places poke at [rs]q->vq->vdev->priv just to get the the vi structure. Let's just pass the pointer around: seems cleaner, and might even be faster. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/net/virtio_net.c | 36 +++++++++++++++++++----------------- 1 file changed, 19 insertions(+), 17 deletions(-) diff --git a/drivers/net/virtio_net.c

Too many places poke at [rs]q->vq->vdev->priv just to get the the vi structure. Let's just pass the pointer around: seems cleaner, and might even be faster. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/net/virtio_net.c | 36 +++++++++++++++++++----------------- 1 file changed, 19 insertions(+), 17 deletions(-) diff --git a/drivers/net/virtio_net.c

On Thu, 2016-03-10 at 09:28 -0500, Aaron Conole wrote: > This patch checks the feature bit for the VIRTIO_NET_F_MTU feature. If it > exists, read the advised MTU and use it. > > No proper error handling is provided for the case where a user changes the > negotiated MTU. A future commit will add proper error handling. Instead, a > warning is emitted if the guest changes the

On Thu, 2016-03-10 at 09:28 -0500, Aaron Conole wrote: > This patch checks the feature bit for the VIRTIO_NET_F_MTU feature. If it > exists, read the advised MTU and use it. > > No proper error handling is provided for the case where a user changes the > negotiated MTU. A future commit will add proper error handling. Instead, a > warning is emitted if the guest changes the

The following changes since commit e1f33be9186363da7955bcb5f0b03e6685544c50: vhost: fix error path in vhost_init_used() (2016-03-02 17:01:49 +0200) are available in the git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git tags/for_linus for you to fetch changes up to c67f5db82027ba6d2ea4ac9176bc45996a03ae6a: virtio_net: replace netdev_alloc_skb_ip_align() with