4.15-stable review patch. If anyone has any objections, please let me know.
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From: Jason Wang jasowang@redhat.com
[ 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 christoffer.dall@linaro.org Fixes: 761876c857cb ("tap: XDP support") Signed-off-by: Jason Wang jasowang@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/tun.c | 1 + 1 file changed, 1 insertion(+)
--- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1490,6 +1490,7 @@ static struct sk_buff *tun_build_skb(str 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();