Commit 0706a78f authored Dec 17, 2021 by Magnus Karlsson Committed by Daniel Borkmann Dec 17, 2021

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



This reverts commit bd0687c1.

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: bd0687c1 ("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

parent 8ca4090f

net/xdp/xsk.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -677,6 +677,8 @@ 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;

		@@ -688,8 +690,6 @@ 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))