Please, don't take directly, conflicts with io_uring. To have per request buffer notifications each zerocopy io_uring send request allocates a new ubuf_info. However, as an skb can carry only one uarg, it may force the stack to create many small skbs hurting performance in many ways. The patchset implements notification, i.e. an io_uring's ubuf_info extension, stacking. It attempts to link ubuf_info's into a list, allowing to have multiple of them per skb. liburing/examples/send-zerocopy shows up 6 times performance improvement for TCP with 4KB bytes per send, and levels it with MSG_ZEROCOPY. Without the patchset it requires much larger sends to utilise all potential. bytes | before | after (Kqps) 1200 | 195 | 1023 4000 | 193 | 1386 8000 | 154 | 1058 The patches are on top of net-next + io_uring-next: https://github.com/isilence/linux.git iou-sendzc/notif-stacking-v2 First two patches based on net-next: https://github.com/isilence/linux.git iou-sendzc/notif-stacking-v2-netonly v2: convert xen-netback to ubuf_info_ops (patch 1) drop two separately merged io_uring patches Pavel Begunkov (4): net: extend ubuf_info callback to ops structure net: add callback for setting a ubuf_info to skb io_uring/notif: simplify io_notif_flush() io_uring/notif: implement notification stacking drivers/net/tap.c | 2 +- drivers/net/tun.c | 2 +- drivers/net/xen-netback/common.h | 5 +- drivers/net/xen-netback/interface.c | 2 +- drivers/net/xen-netback/netback.c | 11 ++-- drivers/vhost/net.c | 8 ++- include/linux/skbuff.h | 21 +++++--- io_uring/notif.c | 83 +++++++++++++++++++++++++---- io_uring/notif.h | 12 ++--- net/core/skbuff.c | 36 ++++++++----- 10 files changed, 134 insertions(+), 48 deletions(-) -- 2.44.0
