[bpf-next PATCH v3 3/7] bpf: sockmap sample, use fork() for send and recv

John Fastabend
2018-01-12T05:07:05Z

Currently for SENDMSG tests first send completes then recv runs. This
does not work well for large data sizes and/or many iterations. So
fork the recv and send handler so that we run both send and recv. In
the future we can add a parameter to do more than a single fork of
tx/rx.

With this we can get many GBps of data which helps exercise the
sockmap code.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
---
samples/sockmap/sockmap_user.c | 58 +++++++++++++++++++++++++++++-----------
1 file changed, 42 insertions(+), 16 deletions(-)

diff --git a/samples/sockmap/sockmap_user.c b/samples/sockmap/sockmap_user.c
index 8ec7dbf..bbe9587 100644
--- a/samples/sockmap/sockmap_user.c
+++ b/samples/sockmap/sockmap_user.c
@@ -23,6 +23,7 @@
#include <stdbool.h>
#include <signal.h>
#include <fcntl.h>
+#include <sys/wait.h>

#include <sys/time.h>
#include <sys/types.h>
@@ -195,7 +196,7 @@ static int msg_loop(int fd, int iov_count, int iov_length, int cnt,
{
struct msghdr msg = {0};
struct iovec *iov;
- int i, flags = 0;
+ int i, flags = MSG_NOSIGNAL;

iov = calloc(iov_count, sizeof(struct iovec));
if (!iov)
@@ -274,25 +275,50 @@ static int msg_loop(int fd, int iov_count, int iov_length, int cnt,

static int sendmsg_test(int iov_count, int iov_buf, int cnt, int verbose)
{
+ int txpid, rxpid, err = 0;
struct msg_stats s = {0};
- int err;
-
- err = msg_loop(c1, iov_count, iov_buf, cnt, &s, true);
- if (err) {
- fprintf(stderr,
- "msg_loop_tx: iov_count %i iov_buf %i cnt %i err %i\n",
- iov_count, iov_buf, cnt, err);
- return err;
+ int status;
+
+ errno = 0;
+
+ rxpid = fork();
+ if (rxpid == 0) {
+ err = msg_loop(p2, iov_count, iov_buf, cnt, &s, false);
+ if (err)
+ fprintf(stderr,
+ "msg_loop_rx: iov_count %i iov_buf %i cnt %i err %i\n",
+ iov_count, iov_buf, cnt, err);
+ fprintf(stdout, "rx_sendmsg: TX_bytes %zu RX_bytes %zu\n",
+ s.bytes_sent, s.bytes_recvd);
+ shutdown(p2, SHUT_RDWR);
+ shutdown(p1, SHUT_RDWR);
+ exit(1);
+ } else if (rxpid == -1) {
+ perror("msg_loop_rx: ");
+ return errno;
}

- msg_loop(p2, iov_count, iov_buf, cnt, &s, false);
- if (err)
- fprintf(stderr,
- "msg_loop_rx: iov_count %i iov_buf %i cnt %i err %i\n",
- iov_count, iov_buf, cnt, err);
+ txpid = fork();
+ if (txpid == 0) {
+ err = msg_loop(c1, iov_count, iov_buf, cnt, &s, true);
+ if (err)
+ fprintf(stderr,
+ "msg_loop_tx: iov_count %i iov_buf %i cnt %i err %i\n",
+ iov_count, iov_buf, cnt, err);
+ fprintf(stdout, "tx_sendmsg: TX_bytes %zu RX_bytes %zu\n",
+ s.bytes_sent, s.bytes_recvd);
+ shutdown(c1, SHUT_RDWR);
+ exit(1);
+ } else if (txpid == -1) {
+ perror("msg_loop_tx: ");
+ return errno;
+ }

- fprintf(stdout, "sendmsg: TX_bytes %zu RX_bytes %zu\n",
- s.bytes_sent, s.bytes_recvd);
+ assert(waitpid(rxpid, &status, 0) == rxpid);
+ if (!txpid)
+ goto out;
+ assert(waitpid(txpid, &status, 0) == txpid);
+out:
return err;
}