From 1903344b6320e18b82cb9f49c0e9b8fd0f80b695 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Sat, 24 Feb 2018 11:32:26 +0800 Subject: [PATCH] tuntap: correctly add the missing XDP flush [ Upstream commit 1bb4f2e868a2891ab8bc668b8173d6ccb8c4ce6f ] We don't flush batched XDP packets through xdp_do_flush_map(), this will cause packets stall at TX queue. Consider we don't do XDP on NAPI poll(), the only possible fix is to call xdp_do_flush_map() immediately after xdp_do_redirect(). Note, this in fact won't try to batch packets through devmap, we could address in the future. Reported-by: Christoffer Dall Fixes: 761876c857cb ("tap: XDP support") Signed-off-by: Jason Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/tun.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index fa51b7b0e9ea..ca55f808b7a9 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1333,6 +1333,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, get_page(alloc_frag->page); alloc_frag->offset += buflen; err = xdp_do_redirect(tun->dev, &xdp, xdp_prog); + xdp_do_flush_map(); if (err) goto err_redirect; rcu_read_unlock(); -- 2.20.1