From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Jason Wang To: netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: mst@redhat.com, sergei.shtylyov@cogentembedded.com, christoffer.dall@linaro.org, brouer@redhat.com, Jason Wang Subject: [PATCH V4 net 3/3] tuntap: correctly add the missing XDP flush Date: Sat, 24 Feb 2018 11:32:26 +0800 Message-Id: <1519443146-9089-3-git-send-email-jasowang@redhat.com> In-Reply-To: <1519443146-9089-1-git-send-email-jasowang@redhat.com> References: <1519443146-9089-1-git-send-email-jasowang@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 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 --- drivers/net/tun.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 63d39fe6..7433bb2 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1663,6 +1663,7 @@ 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(); -- 2.7.4