Revert "xsk: Do not sleep in poll() when need_wakeup set"

commit 0706a78f31 upstream.

This reverts commit bd0687c18e.

This patch causes a Tx only workload to go to sleep even when it does
not have to, leading to misserable performance in skb mode. It fixed
one rare problem but created a much worse one, so this need to be
reverted while I try to craft a proper solution to the original
problem.

Fixes: bd0687c18e ("xsk: Do not sleep in poll() when need_wakeup set")
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211217145646.26449-1-magnus.karlsson@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Magnus Karlsson 2021-12-17 15:56:46 +01:00 committed by Greg Kroah-Hartman
parent 581b097951
commit ffbd663eba

View file

@ -692,6 +692,8 @@ static __poll_t xsk_poll(struct file *file, struct socket *sock,
struct xdp_sock *xs = xdp_sk(sk);
struct xsk_buff_pool *pool;
sock_poll_wait(file, sock, wait);
if (unlikely(!xsk_is_bound(xs)))
return mask;
@ -703,8 +705,6 @@ static __poll_t xsk_poll(struct file *file, struct socket *sock,
else
/* Poll needs to drive Tx also in copy mode */
__xsk_sendmsg(sk);
} else {
sock_poll_wait(file, sock, wait);
}
if (xs->rx && !xskq_prod_is_empty(xs->rx))