similar to: [PATCH net-next V2 00/11] vhost_net TX batching

Hi all: This series tries to batch submitting packets to underlayer socket through msg_control during sendmsg(). This is done by: 1) Doing userspace copy inside vhost_net 2) Build XDP buff 3) Batch at most 64 (VHOST_NET_BATCH) XDP buffs and submit them once through msg_control during sendmsg(). 4) Underlayer sockets can use XDP buffs directly when XDP is enalbed, or build skb based on XDP

Hi all: We do not support XDP batching for TUN since it can only receive one packet a time from vhost_net. This series tries to remove this limitation by: - introduce a TUN specific msg_control that can hold a pointer to an array of XDP buffs - try copy and build XDP buff in vhost_net - store XDP buffs in an array and submit them once for every N packets from vhost_net - since TUN can only

On Thu, Sep 06, 2018 at 12:05:21PM +0800, Jason Wang wrote: > This patch split out XDP logic into a single function. This make it to > be reused by XDP batching path in the following patch. > > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/net/tun.c | 84 ++++++++++++++++++++++++++++------------------- > 1 file changed, 51 insertions(+), 33

On Thu, Sep 06, 2018 at 12:05:21PM +0800, Jason Wang wrote: > This patch split out XDP logic into a single function. This make it to > be reused by XDP batching path in the following patch. > > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/net/tun.c | 84 ++++++++++++++++++++++++++++------------------- > 1 file changed, 51 insertions(+), 33

On Thu, Sep 06, 2018 at 12:05:19PM +0800, Jason Wang wrote: > There's no need to duplicate page get logic in each action. So this > patch tries to get page and calculate the offset before processing XDP > actions, and undo them when meet errors (we don't care the performance > on errors). This will be used for factoring out XDP logic. > > Signed-off-by: Jason Wang

On Thu, Sep 06, 2018 at 12:05:19PM +0800, Jason Wang wrote: > There's no need to duplicate page get logic in each action. So this > patch tries to get page and calculate the offset before processing XDP > actions, and undo them when meet errors (we don't care the performance > on errors). This will be used for factoring out XDP logic. > > Signed-off-by: Jason Wang

We do a get_page() which involves a atomic operation. This patch tries to mitigate a per packet atomic operation by maintaining a reference bias which is initially USHRT_MAX. Each time a page is got, instead of calling get_page() we decrease the bias and when we find it's time to use a new page we will decrease the bias at one time through __page_cache_drain_cache(). Testpmd(virtio_user +

On Thu, Sep 06, 2018 at 12:05:20PM +0800, Jason Wang wrote: > If we're sure not to go native XDP, there's no need for several things > like bh and rcu stuffs. > > Signed-off-by: Jason Wang <jasowang at redhat.com> True... > --- > drivers/net/tun.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/drivers/net/tun.c

Hi: This series tries to re-enable XDP_REDIRECT for mergeable buffer which was removed since commit 7324f5399b06 ("virtio_net: disable XDP_REDIRECT in receive_mergeable() case"). Main concerns are: - not enough tailroom was reserved which breaks cpumap - complex logic like EWMA and linearizing during XDP processing Fix those by: - reserve enough tailroom during refill - disable EWMA

Hi: This series tries to re-enable XDP_REDIRECT for mergeable buffer which was removed since commit 7324f5399b06 ("virtio_net: disable XDP_REDIRECT in receive_mergeable() case"). Main concerns are: - not enough tailroom was reserved which breaks cpumap - complex logic like EWMA and linearizing during XDP processing Fix those by: - reserve enough tailroom during refill - disable EWMA

On Thu, Sep 06, 2018 at 12:05:26PM +0800, Jason Wang wrote: > This patch implements XDP batching for vhost_net. The idea is first to > try to do userspace copy and build XDP buff directly in vhost. Instead > of submitting the packet immediately, vhost_net will batch them in an > array and submit every 64 (VHOST_NET_BATCH) packets to the under layer > sockets through msg_control of

On Thu, Sep 06, 2018 at 12:05:26PM +0800, Jason Wang wrote: > This patch implements XDP batching for vhost_net. The idea is first to > try to do userspace copy and build XDP buff directly in vhost. Instead > of submitting the packet immediately, vhost_net will batch them in an > array and submit every 64 (VHOST_NET_BATCH) packets to the under layer > sockets through msg_control of

On Mon, 21 May 2018 17:04:31 +0800 Jason wrote: > This patch implement build XDP buffers in vhost_net. The idea is do > userspace copy in vhost_net and build XDP buff based on the > page. Vhost_net can then submit one or an array of XDP buffs to > underlayer socket (e.g TUN). TUN can choose to do XDP or call > build_skb() to build skb. To support build skb, vnet header were also

On Thu, Sep 06, 2018 at 12:05:22PM +0800, Jason Wang wrote: > This will allow adding batch flushing on top. > > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/net/tun.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/tun.c b/drivers/net/tun.c > index 21b125020b3b..ff1cbf3ebd50 100644 > ---

On Thu, Sep 06, 2018 at 12:05:23PM +0800, Jason Wang wrote: > This patch introduces to a new tun/tap specific msg_control: > > #define TUN_MSG_UBUF 1 > #define TUN_MSG_PTR 2 > struct tun_msg_ctl { > int type; > void *ptr; > }; > > This allows us to pass different kinds of msg_control through > sendmsg(). The first supported type is ubuf

Hi: This series brings two optimizations for virtio-net XDP: - avoid reset during XDP set - turn off offloads on demand Please review. Thanks Jason Wang (5): virtio_ring: allow to store zero as the ctx virtio-net: pack headroom into ctx for mergeable buffer virtio-net: switch to use new ctx API for small buffer virtio-net: do not reset during XDP set virtio-net: switch off offloads

Hi: This series brings two optimizations for virtio-net XDP: - avoid reset during XDP set - turn off offloads on demand Please review. Thanks Jason Wang (5): virtio_ring: allow to store zero as the ctx virtio-net: pack headroom into ctx for mergeable buffer virtio-net: switch to use new ctx API for small buffer virtio-net: do not reset during XDP set virtio-net: switch off offloads

Hi: This series brings two optimizations for virtio-net XDP: - avoid reset during XDP set - turn off offloads on demand Changes from V1: - Various tweaks on commit logs and comments - Use virtnet_napi_enable() when enabling NAPI on XDP set - Copy the small buffer packet only if xdp_headroom is smaller than required Please review. Thanks Jason Wang (5): virtio_ring: allow to store zero as

Hi: This series brings two optimizations for virtio-net XDP: - avoid reset during XDP set - turn off offloads on demand Changes from V1: - Various tweaks on commit logs and comments - Use virtnet_napi_enable() when enabling NAPI on XDP set - Copy the small buffer packet only if xdp_headroom is smaller than required Please review. Thanks Jason Wang (5): virtio_ring: allow to store zero as

On Thu, Sep 06, 2018 at 12:05:17PM +0800, Jason Wang wrote: > Signed-off-by: Jason Wang <jasowang at redhat.com> Acked-by: Michael S. Tsirkin <mst at redhat.com> any idea why didn't we do this straight away? > --- > drivers/net/tun.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/net/tun.c b/drivers/net/tun.c > index