vsock: report pending receive data to io_uring

Browse source

AF_VSOCK stream receives never fill msghdr.msg_inq, so io_uring cannot set
IORING_CQE_F_SOCK_NONEMPTY and retries a multishot receive even after the
queue has been drained.

Fill the hint at the common receive exit using the transport callback that
SIOCINQ already uses, and report 1 once the connection is finished so the
caller performs the receive which observes EOF, as TCP does after a FIN.

A vsock loopback ping-pong with io_uring multishot receive drops entries
into __vsock_connectible_recvmsg from 1.97 to 1.00 per delivered message,
and receiver CPU time by about 3% (25 runs of 50000 messages, p=0.006).

Signed-off-by: David Carlier <devnexen@gmail.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://patch.msgid.link/20260923184008.153541-2-devnexen@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

...

This commit is contained in:

David Carlier 2026-09-23 19:40:07 +01:00 • committed by Jakub Kicinski

parent df2d695617

commit 608e7f8496

1 changed files with 35 additions and 0 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

35

net/vmw_vsock/af_vsock.c

View file