diff mbox series

[bpf-next,v3,08/10] samples/bpf: use recvfrom() in xdpsock/l2fwd

Message ID 20201119083024.119566-9-bjorn.topel@gmail.com (mailing list archive)
State New, archived
Delegated to: BPF
Headers show
Series Introduce preferred busy-polling | expand

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netdev/source_inline warning Was 1 now: 1
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netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch warning WARNING: line length of 102 exceeds 80 columns WARNING: line length of 94 exceeds 80 columns
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/header_inline success Link
netdev/stable success Stable not CCed

Commit Message

Björn Töpel Nov. 19, 2020, 8:30 a.m. UTC 
From: Björn Töpel <bjorn.topel@intel.com>

Start using recvfrom() the l2fwd scenario, instead of poll() which is
more expensive and need additional knobs for busy-polling.

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
---
 samples/bpf/xdpsock_user.c | 25 +++++++++++--------------
 1 file changed, 11 insertions(+), 14 deletions(-)

Comments

Magnus Karlsson Nov. 25, 2020, 8 a.m. UTC | #1 
On Thu, Nov 19, 2020 at 9:33 AM Björn Töpel <bjorn.topel@gmail.com> wrote:
>
> From: Björn Töpel <bjorn.topel@intel.com>
>
> Start using recvfrom() the l2fwd scenario, instead of poll() which is
> more expensive and need additional knobs for busy-polling.
>
> Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
> ---
>  samples/bpf/xdpsock_user.c | 25 +++++++++++--------------
>  1 file changed, 11 insertions(+), 14 deletions(-)

Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>

> diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c
> index f90111b95b2e..24aa7511c4c8 100644
> --- a/samples/bpf/xdpsock_user.c
> +++ b/samples/bpf/xdpsock_user.c
> @@ -1098,8 +1098,7 @@ static void kick_tx(struct xsk_socket_info *xsk)
>         exit_with_error(errno);
>  }
>
> -static inline void complete_tx_l2fwd(struct xsk_socket_info *xsk,
> -                                    struct pollfd *fds)
> +static inline void complete_tx_l2fwd(struct xsk_socket_info *xsk)
>  {
>         struct xsk_umem_info *umem = xsk->umem;
>         u32 idx_cq = 0, idx_fq = 0;
> @@ -1134,7 +1133,7 @@ static inline void complete_tx_l2fwd(struct xsk_socket_info *xsk,
>                                 exit_with_error(-ret);
>                         if (xsk_ring_prod__needs_wakeup(&umem->fq)) {
>                                 xsk->app_stats.fill_fail_polls++;
> -                               ret = poll(fds, num_socks, opt_timeout);
> +                               recvfrom(xsk_socket__fd(xsk->xsk), NULL, 0, MSG_DONTWAIT, NULL, NULL);
>                         }
>                         ret = xsk_ring_prod__reserve(&umem->fq, rcvd, &idx_fq);
>                 }
> @@ -1331,19 +1330,19 @@ static void tx_only_all(void)
>                 complete_tx_only_all();
>  }
>
> -static void l2fwd(struct xsk_socket_info *xsk, struct pollfd *fds)
> +static void l2fwd(struct xsk_socket_info *xsk)
>  {
>         unsigned int rcvd, i;
>         u32 idx_rx = 0, idx_tx = 0;
>         int ret;
>
> -       complete_tx_l2fwd(xsk, fds);
> +       complete_tx_l2fwd(xsk);
>
>         rcvd = xsk_ring_cons__peek(&xsk->rx, opt_batch_size, &idx_rx);
>         if (!rcvd) {
>                 if (xsk_ring_prod__needs_wakeup(&xsk->umem->fq)) {
>                         xsk->app_stats.rx_empty_polls++;
> -                       ret = poll(fds, num_socks, opt_timeout);
> +                       recvfrom(xsk_socket__fd(xsk->xsk), NULL, 0, MSG_DONTWAIT, NULL, NULL);
>                 }
>                 return;
>         }
> @@ -1353,7 +1352,7 @@ static void l2fwd(struct xsk_socket_info *xsk, struct pollfd *fds)
>         while (ret != rcvd) {
>                 if (ret < 0)
>                         exit_with_error(-ret);
> -               complete_tx_l2fwd(xsk, fds);
> +               complete_tx_l2fwd(xsk);
>                 if (xsk_ring_prod__needs_wakeup(&xsk->tx)) {
>                         xsk->app_stats.tx_wakeup_sendtos++;
>                         kick_tx(xsk);
> @@ -1388,22 +1387,20 @@ static void l2fwd_all(void)
>         struct pollfd fds[MAX_SOCKS] = {};
>         int i, ret;
>
> -       for (i = 0; i < num_socks; i++) {
> -               fds[i].fd = xsk_socket__fd(xsks[i]->xsk);
> -               fds[i].events = POLLOUT | POLLIN;
> -       }
> -
>         for (;;) {
>                 if (opt_poll) {
> -                       for (i = 0; i < num_socks; i++)
> +                       for (i = 0; i < num_socks; i++) {
> +                               fds[i].fd = xsk_socket__fd(xsks[i]->xsk);
> +                               fds[i].events = POLLOUT | POLLIN;
>                                 xsks[i]->app_stats.opt_polls++;
> +                       }
>                         ret = poll(fds, num_socks, opt_timeout);
>                         if (ret <= 0)
>                                 continue;
>                 }
>
>                 for (i = 0; i < num_socks; i++)
> -                       l2fwd(xsks[i], fds);
> +                       l2fwd(xsks[i]);
>
>                 if (benchmark_done)
>                         break;
> --
> 2.27.0
>
diff mbox series

Patch

diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c
index f90111b95b2e..24aa7511c4c8 100644
--- a/samples/bpf/xdpsock_user.c
+++ b/samples/bpf/xdpsock_user.c
@@ -1098,8 +1098,7 @@  static void kick_tx(struct xsk_socket_info *xsk)
 	exit_with_error(errno);
 }
 
-static inline void complete_tx_l2fwd(struct xsk_socket_info *xsk,
-				     struct pollfd *fds)
+static inline void complete_tx_l2fwd(struct xsk_socket_info *xsk)
 {
 	struct xsk_umem_info *umem = xsk->umem;
 	u32 idx_cq = 0, idx_fq = 0;
@@ -1134,7 +1133,7 @@  static inline void complete_tx_l2fwd(struct xsk_socket_info *xsk,
 				exit_with_error(-ret);
 			if (xsk_ring_prod__needs_wakeup(&umem->fq)) {
 				xsk->app_stats.fill_fail_polls++;
-				ret = poll(fds, num_socks, opt_timeout);
+				recvfrom(xsk_socket__fd(xsk->xsk), NULL, 0, MSG_DONTWAIT, NULL, NULL);
 			}
 			ret = xsk_ring_prod__reserve(&umem->fq, rcvd, &idx_fq);
 		}
@@ -1331,19 +1330,19 @@  static void tx_only_all(void)
 		complete_tx_only_all();
 }
 
-static void l2fwd(struct xsk_socket_info *xsk, struct pollfd *fds)
+static void l2fwd(struct xsk_socket_info *xsk)
 {
 	unsigned int rcvd, i;
 	u32 idx_rx = 0, idx_tx = 0;
 	int ret;
 
-	complete_tx_l2fwd(xsk, fds);
+	complete_tx_l2fwd(xsk);
 
 	rcvd = xsk_ring_cons__peek(&xsk->rx, opt_batch_size, &idx_rx);
 	if (!rcvd) {
 		if (xsk_ring_prod__needs_wakeup(&xsk->umem->fq)) {
 			xsk->app_stats.rx_empty_polls++;
-			ret = poll(fds, num_socks, opt_timeout);
+			recvfrom(xsk_socket__fd(xsk->xsk), NULL, 0, MSG_DONTWAIT, NULL, NULL);
 		}
 		return;
 	}
@@ -1353,7 +1352,7 @@  static void l2fwd(struct xsk_socket_info *xsk, struct pollfd *fds)
 	while (ret != rcvd) {
 		if (ret < 0)
 			exit_with_error(-ret);
-		complete_tx_l2fwd(xsk, fds);
+		complete_tx_l2fwd(xsk);
 		if (xsk_ring_prod__needs_wakeup(&xsk->tx)) {
 			xsk->app_stats.tx_wakeup_sendtos++;
 			kick_tx(xsk);
@@ -1388,22 +1387,20 @@  static void l2fwd_all(void)
 	struct pollfd fds[MAX_SOCKS] = {};
 	int i, ret;
 
-	for (i = 0; i < num_socks; i++) {
-		fds[i].fd = xsk_socket__fd(xsks[i]->xsk);
-		fds[i].events = POLLOUT | POLLIN;
-	}
-
 	for (;;) {
 		if (opt_poll) {
-			for (i = 0; i < num_socks; i++)
+			for (i = 0; i < num_socks; i++) {
+				fds[i].fd = xsk_socket__fd(xsks[i]->xsk);
+				fds[i].events = POLLOUT | POLLIN;
 				xsks[i]->app_stats.opt_polls++;
+			}
 			ret = poll(fds, num_socks, opt_timeout);
 			if (ret <= 0)
 				continue;
 		}
 
 		for (i = 0; i < num_socks; i++)
-			l2fwd(xsks[i], fds);
+			l2fwd(xsks[i]);
 
 		if (benchmark_done)
 			break;