similar to: [PATCH 1/4] virtio_net: use DECLARE_EWMA

On Thu, Mar 01, 2018 at 11:19:04AM +0800, Jason Wang wrote: > XDP_REDIRECT support for mergeable buffer was removed since commit > 7324f5399b06 ("virtio_net: disable XDP_REDIRECT in receive_mergeable() > case"). This is because we don't reserve enough tailroom for struct > skb_shared_info which breaks XDP assumption. Other complaints are, the > complex linearize logic

XDP_REDIRECT support for mergeable buffer was removed since commit 7324f5399b06 ("virtio_net: disable XDP_REDIRECT in receive_mergeable() case"). This is because we don't reserve enough tailroom for struct skb_shared_info which breaks XDP assumption. Other complaints are, the complex linearize logic and EWMA estimation may increase the possibility of linearizing. Signed-off-by:

On Fri, Mar 02, 2018 at 05:29:14PM +0800, Jason Wang wrote: > XDP_REDIRECT support for mergeable buffer was removed since commit > 7324f5399b06 ("virtio_net: disable XDP_REDIRECT in receive_mergeable() > case"). This is because we don't reserve enough tailroom for struct > skb_shared_info which breaks XDP assumption. So this patch fixes this > by reserving enough

XDP_REDIRECT support for mergeable buffer was removed since commit 7324f5399b06 ("virtio_net: disable XDP_REDIRECT in receive_mergeable() case"). This is because we don't reserve enough tailroom for struct skb_shared_info which breaks XDP assumption. So this patch fixes this by reserving enough tailroom and using fixed size of rx buffer. Signed-off-by: Jason Wang <jasowang at

XDP_REDIRECT support for mergeable buffer was removed since commit 7324f5399b06 ("virtio_net: disable XDP_REDIRECT in receive_mergeable() case"). This is because we don't reserve enough tailroom for struct skb_shared_info which breaks XDP assumption. So this patch fixes this by reserving enough tailroom and using fixed size of rx buffer. Signed-off-by: Jason Wang <jasowang at

Add initial support for per-rx queue sysfs attributes to virtio-net. If mergeable packet buffers are enabled, adds a read-only mergeable packet buffer size sysfs attribute for each RX queue. Signed-off-by: Michael Dalton <mwdalton at google.com> --- drivers/net/virtio_net.c | 66 +++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 62 insertions(+), 4 deletions(-) diff --git

When ring size is small (<32 entries) making buffers smaller means a full ring might not be able to hold enough buffers to fit a single large packet. Make sure a ring full of buffers is large enough to allow at least one packet of max size. Fixes: 2613af0ed18a ("virtio_net: migrate mergeable rx buffers to page frag allocators") Signed-off-by: Michael S. Tsirkin <mst at

When ring size is small (<32 entries) making buffers smaller means a full ring might not be able to hold enough buffers to fit a single large packet. Make sure a ring full of buffers is large enough to allow at least one packet of max size. Fixes: 2613af0ed18a ("virtio_net: migrate mergeable rx buffers to page frag allocators") Signed-off-by: Michael S. Tsirkin <mst at

When ring size is small (<32 entries) making buffers smaller means a full ring might not be able to hold enough buffers to fit a single large packet. Make sure a ring full of buffers is large enough to allow at least one packet of max size. Fixes: 2613af0ed18a ("virtio_net: migrate mergeable rx buffers to page frag allocators") Signed-off-by: Michael S. Tsirkin <mst at

When ring size is small (<32 entries) making buffers smaller means a full ring might not be able to hold enough buffers to fit a single large packet. Make sure a ring full of buffers is large enough to allow at least one packet of max size. Fixes: 2613af0ed18a ("virtio_net: migrate mergeable rx buffers to page frag allocators") Signed-off-by: Michael S. Tsirkin <mst at

On Thu, Jan 16, 2014 at 01:38:46AM -0800, Michael Dalton wrote: > Add initial support for per-rx queue sysfs attributes to virtio-net. If > mergeable packet buffers are enabled, adds a read-only mergeable packet > buffer size sysfs attribute for each RX queue. > > Signed-off-by: Michael Dalton <mwdalton at google.com> > --- > drivers/net/virtio_net.c | 66

On Thu, Jan 16, 2014 at 01:38:46AM -0800, Michael Dalton wrote: > Add initial support for per-rx queue sysfs attributes to virtio-net. If > mergeable packet buffers are enabled, adds a read-only mergeable packet > buffer size sysfs attribute for each RX queue. > > Signed-off-by: Michael Dalton <mwdalton at google.com> > --- > drivers/net/virtio_net.c | 66

XDP_REDIRECT support for mergeable buffer was removed since commit 7324f5399b06 ("virtio_net: disable XDP_REDIRECT in receive_mergeable() case"). This is because we don't reserve enough tailroom for struct skb_shared_info which breaks XDP assumption. So this patch fixes this by reserving enough tailroom and using fixed size of rx buffer. Signed-off-by: Jason Wang <jasowang at

XDP_REDIRECT support for mergeable buffer was removed since commit 7324f5399b06 ("virtio_net: disable XDP_REDIRECT in receive_mergeable() case"). This is because we don't reserve enough tailroom for struct skb_shared_info which breaks XDP assumption. So this patch fixes this by reserving enough tailroom and using fixed size of rx buffer. Signed-off-by: Jason Wang <jasowang at

Add initial support for per-rx queue sysfs attributes to virtio-net. If mergeable packet buffers are enabled, adds a read-only mergeable packet buffer size sysfs attribute for each RX queue. Suggested-by: Michael S. Tsirkin <mst at redhat.com> Signed-off-by: Michael Dalton <mwdalton at google.com> --- v3->v4: Remove seqcount due to EWMA changes in patch 5. Add missing

Add initial support for debugfs to virtio-net. Each virtio-net network device will have a directory under /virtio-net in debugfs. The per-network device directory will contain one sub-directory per active, enabled receive queue. If mergeable receive buffers are enabled, each receive queue directory will contain a read-only file that returns the current packet buffer size for the receive queue.

We don't need to align length to any particular value anymore. Aligning to L1 cache size probably sill makes sense to reduce false sharing. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/net/virtio_net.c | 13 +------------ 1 file changed, 1 insertion(+), 12 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 94f94f3..824dd95 100644

We don't need to align length to any particular value anymore. Aligning to L1 cache size probably sill makes sense to reduce false sharing. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/net/virtio_net.c | 13 +------------ 1 file changed, 1 insertion(+), 12 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 94f94f3..824dd95 100644

From: Johannes Berg <johannes.berg at intel.com> Declaring the factor is counter-intuitive, and people are prone to using small(-ish) values even when that makes no sense. Change the DECLARE_EWMA() macro to take the fractional precision, in bits, rather than a factor, and update all users. While at it, add some more documentation. Signed-off-by: Johannes Berg <johannes.berg at

From: Johannes Berg <johannes.berg at intel.com> Declaring the factor is counter-intuitive, and people are prone to using small(-ish) values even when that makes no sense. Change the DECLARE_EWMA() macro to take the fractional precision, in bits, rather than a factor, and update all users. While at it, add some more documentation. Signed-off-by: Johannes Berg <johannes.berg at