From 90da4b3208d32bdb5489ca08b91af16ed4a68d00 Mon Sep 17 00:00:00 2001 From: Magnus Karlsson Date: Mon, 16 Nov 2020 12:12:43 +0100 Subject: samples/bpf: Increment Tx stats at sending Increment the statistics over how many Tx packets have been sent at the time of sending instead of at the time of completion. This as a completion event means that the buffer has been sent AND returned to user space. The packet always gets sent shortly after sendto() is called. The kernel might, for performance reasons, decide to not return every single buffer to user space immediately after sending, for example, only after a batch of packets have been transmitted. Incrementing the number of packets sent at completion, will in that case be confusing as if you send a single packet, the counter might show zero for a while even though the packet has been transmitted. Signed-off-by: Magnus Karlsson Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/1605525167-14450-2-git-send-email-magnus.karlsson@gmail.com --- samples/bpf/xdpsock_user.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'samples') diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c index 1149e94ca32f..2567f0db5aca 100644 --- a/samples/bpf/xdpsock_user.c +++ b/samples/bpf/xdpsock_user.c @@ -1146,7 +1146,6 @@ static inline void complete_tx_l2fwd(struct xsk_socket_info *xsk, xsk_ring_prod__submit(&xsk->umem->fq, rcvd); xsk_ring_cons__release(&xsk->umem->cq, rcvd); xsk->outstanding_tx -= rcvd; - xsk->ring_stats.tx_npkts += rcvd; } } @@ -1168,7 +1167,6 @@ static inline void complete_tx_only(struct xsk_socket_info *xsk, if (rcvd > 0) { xsk_ring_cons__release(&xsk->umem->cq, rcvd); xsk->outstanding_tx -= rcvd; - xsk->ring_stats.tx_npkts += rcvd; } } @@ -1260,6 +1258,7 @@ static void tx_only(struct xsk_socket_info *xsk, u32 *frame_nb, int batch_size) } xsk_ring_prod__submit(&xsk->tx, batch_size); + xsk->ring_stats.tx_npkts += batch_size; xsk->outstanding_tx += batch_size; *frame_nb += batch_size; *frame_nb %= NUM_FRAMES; @@ -1348,6 +1347,7 @@ static void l2fwd(struct xsk_socket_info *xsk, struct pollfd *fds) } return; } + xsk->ring_stats.rx_npkts += rcvd; ret = xsk_ring_prod__reserve(&xsk->tx, rcvd, &idx_tx); while (ret != rcvd) { @@ -1379,7 +1379,7 @@ static void l2fwd(struct xsk_socket_info *xsk, struct pollfd *fds) xsk_ring_prod__submit(&xsk->tx, rcvd); xsk_ring_cons__release(&xsk->rx, rcvd); - xsk->ring_stats.rx_npkts += rcvd; + xsk->ring_stats.tx_npkts += rcvd; xsk->outstanding_tx += rcvd; } -- cgit v1.2.3-59-g8ed1b