similar to: [PATCH net-next] vhost_net: batch used ring update in rx

After commit e2b3b35eb989 ("vhost_net: batch used ring update in rx"), we tend to batch updating used heads. But it doesn't flush batched heads before trying to do busy polling, this will cause vhost to wait for guest TX which waits for the used RX. Fixing by flush batched heads before busy loop. 1 byte TCP_RR performance recovers from 13107.83 to 50402.65. Fixes: e2b3b35eb989

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 2020/6/2 ??9:06, Michael S. Tsirkin wrote: > Convert vhost net to use the new format-agnostic API. > In particular, don't poke at vq internals such as the > heads array. > > Signed-off-by: Michael S. Tsirkin <mst at redhat.com> > --- > drivers/vhost/net.c | 153 +++++++++++++++++++++++--------------------- > 1 file changed, 81 insertions(+), 72 deletions(-)

Move get_rx_bufs() to vhost.c and rename it to vhost_get_rx_bufs(). This helps to hide vring internal layout from specific device implementation. Packed ring implementation will benefit from this. Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/vhost/net.c | 83 ++------------------------------------------------- drivers/vhost/vhost.c | 78

On Mon, Apr 23, 2018 at 01:34:53PM +0800, Jason Wang wrote: > Move get_rx_bufs() to vhost.c and rename it to > vhost_get_rx_bufs(). This helps to hide vring internal layout from A small typo. Based on the code change in this patch, it seems that this function is renamed to vhost_get_bufs(). Thanks > specific device implementation. Packed ring implementation will > benefit from

This patch adds mergeable receive buffer support to vhost_net. Signed-off-by: David L Stevens <dlstevens at us.ibm.com> diff -ruNp net-next-v0/drivers/vhost/net.c net-next-v7/drivers/vhost/net.c --- net-next-v0/drivers/vhost/net.c 2010-04-24 21:36:54.000000000 -0700 +++ net-next-v7/drivers/vhost/net.c 2010-04-28 12:26:18.000000000 -0700 @@ -74,6 +74,23 @@ static int move_iovec_hdr(struct

This patch adds mergeable receive buffer support to vhost_net. Signed-off-by: David L Stevens <dlstevens at us.ibm.com> diff -ruNp net-next-v0/drivers/vhost/net.c net-next-v7/drivers/vhost/net.c --- net-next-v0/drivers/vhost/net.c 2010-04-24 21:36:54.000000000 -0700 +++ net-next-v7/drivers/vhost/net.c 2010-04-28 12:26:18.000000000 -0700 @@ -74,6 +74,23 @@ static int move_iovec_hdr(struct

Hi Jason, I love your patch! Yet something to improve: [auto build test ERROR on net-next/master] url: https://github.com/0day-ci/linux/commits/Jason-Wang/Packed-virtqueue-for-vhost/20180703-154751 config: x86_64-randconfig-s0-07032254 (attached as .config) compiler: gcc-6 (Debian 6.4.0-9) 6.4.0 20171026 reproduce: # save the attached .config to linux build tree make

When the rx buffer is too small for a packet, we will discard the vq descriptor and retry it for the next packet: while ((sock_len = vhost_net_rx_peek_head_len(net, sock->sk, &busyloop_intr))) { ... /* On overrun, truncate and discard */ if (unlikely(headcount > UIO_MAXIOV)) { iov_iter_init(&msg.msg_iter, READ, vq->iov, 1, 1); err = sock->ops->recvmsg(sock,

When the rx buffer is too small for a packet, we will discard the vq descriptor and retry it for the next packet: while ((sock_len = vhost_net_rx_peek_head_len(net, sock->sk, &busyloop_intr))) { ... /* On overrun, truncate and discard */ if (unlikely(headcount > UIO_MAXIOV)) { iov_iter_init(&msg.msg_iter, READ, vq->iov, 1, 1); err = sock->ops->recvmsg(sock,

On 2019/4/26 ??1:52, Michael S. Tsirkin wrote: > On Thu, Apr 25, 2019 at 03:33:19AM -0400, Jason Wang wrote: >> When the rx buffer is too small for a packet, we will discard the vq >> descriptor and retry it for the next packet: >> >> while ((sock_len = vhost_net_rx_peek_head_len(net, sock->sk, >> &busyloop_intr))) { >> ... >> /* On

On 2019/4/26 ??1:52, Michael S. Tsirkin wrote: > On Thu, Apr 25, 2019 at 03:33:19AM -0400, Jason Wang wrote: >> When the rx buffer is too small for a packet, we will discard the vq >> descriptor and retry it for the next packet: >> >> while ((sock_len = vhost_net_rx_peek_head_len(net, sock->sk, >> &busyloop_intr))) { >> ... >> /* On

Hi all: This series implements packed virtqueues which were described at [1]. In this version we try to address the performance regression saw by V2. The root cause is packed virtqueue need more times of userspace memory accesssing which turns out to be very expensive. Thanks to the help of 7f466032dc9e ("vhost: access vq metadata through kernel virtual address"), such overhead cold be

Hi all: This series implements packed virtqueues which were described at [1]. In this version we try to address the performance regression saw by V2. The root cause is packed virtqueue need more times of userspace memory accesssing which turns out to be very expensive. Thanks to the help of 7f466032dc9e ("vhost: access vq metadata through kernel virtual address"), such overhead cold be

On Sun, May 05, 2019 at 12:20:24PM +0800, Jason Wang wrote: > > On 2019/4/26 ??3:35, Jason Wang wrote: > > > > On 2019/4/26 ??1:52, Michael S. Tsirkin wrote: > > > On Thu, Apr 25, 2019 at 03:33:19AM -0400, Jason Wang wrote: > > > > When the rx buffer is too small for a packet, we will discard the vq > > > > descriptor and retry it for the next

On Sun, May 05, 2019 at 12:20:24PM +0800, Jason Wang wrote: > > On 2019/4/26 ??3:35, Jason Wang wrote: > > > > On 2019/4/26 ??1:52, Michael S. Tsirkin wrote: > > > On Thu, Apr 25, 2019 at 03:33:19AM -0400, Jason Wang wrote: > > > > When the rx buffer is too small for a packet, we will discard the vq > > > > descriptor and retry it for the next

No need to check the support of mergeable buffer inside the recevie loop as the whole handle_rx()_xx is in the read critical region. So this patch move it ahead of the receiving loop. Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/vhost/net.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index

No need to check the support of mergeable buffer inside the recevie loop as the whole handle_rx()_xx is in the read critical region. So this patch move it ahead of the receiving loop. Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/vhost/net.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index

Hi all: This RFC implement packed ring layout. The code were tested with Tiwei's RFC V2 a thttps://lkml.org/lkml/2018/4/1/48. Some fixups and tweaks were needed on top of Tiwei's code to make it run. TCP stream and pktgen does not show obvious difference compared with split ring. Changes from V2: - do not use & in checking desc_event_flags - off should be most significant bit -

Hi all: This RFC implement packed ring layout. The code were tested with Tiwei's RFC V2 a thttps://lkml.org/lkml/2018/4/1/48. Some fixups and tweaks were needed on top of Tiwei's code to make it run. TCP stream and pktgen does not show obvious difference compared with split ring. Changes from V2: - do not use & in checking desc_event_flags - off should be most significant bit -