From 0706a78f31c4217ca144f630063ec9561a21548d Mon Sep 17 00:00:00 2001
From: Magnus Karlsson <magnus.karlsson@intel.com>
Date: Fri, 17 Dec 2021 15:56:46 +0100
Subject: [PATCH] Revert "xsk: Do not sleep in poll() when need_wakeup set"
This reverts commit bd0687c18e635b63233dc87f38058cd728802ab4.
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: bd0687c18e63 ("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
---
net/xdp/xsk.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index 7a466ea962c57..f16074eb53c72 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -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))
--
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