From: John Fastabend <john.fastabend@gmail.com>
Date: Wed, 13 May 2020 12:14:25 -0700
Subject: bpf: Selftests, improve test_sockmap total bytes counter
Patch-mainline: v5.8-rc1
Git-commit: 18d4e900a4500c54af56b9ad39f4d3b378eb0661
References: bsc#1177028

The recv thread in test_sockmap waits to receive all bytes from sender but
in the case we use pop data it may wait for more bytes then actually being
sent. This stalls the test harness for multiple seconds. Because this
happens in multiple tests it slows time to run the selftest.

Fix by doing a better job of accounting for total bytes when pop helpers
are used.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/158939726542.15176.5964532245173539540.stgit@john-Precision-5820-Tower
Acked-by: Gary Lin <glin@suse.com>
---
 tools/testing/selftests/bpf/test_sockmap.c |   11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

--- a/tools/testing/selftests/bpf/test_sockmap.c
+++ b/tools/testing/selftests/bpf/test_sockmap.c
@@ -502,9 +502,10 @@ static int msg_loop(int fd, int iov_coun
 		 * paths.
 		 */
 		total_bytes = (float)iov_count * (float)iov_length * (float)cnt;
-		txmsg_pop_total = txmsg_pop;
 		if (txmsg_apply)
-			txmsg_pop_total *= (total_bytes / txmsg_apply);
+			txmsg_pop_total = txmsg_pop * (total_bytes / txmsg_apply);
+		else
+			txmsg_pop_total = txmsg_pop * cnt;
 		total_bytes -= txmsg_pop_total;
 		err = clock_gettime(CLOCK_MONOTONIC, &s->start);
 		if (err < 0)
@@ -638,8 +639,12 @@ static int sendmsg_test(struct sockmap_o
 
 	rxpid = fork();
 	if (rxpid == 0) {
+		iov_buf -= (txmsg_pop - txmsg_start_pop + 1);
 		if (opt->drop_expected)
-			exit(0);
+			_exit(0);
+
+		if (!iov_buf) /* zero bytes sent case */
+			_exit(0);
 
 		if (opt->sendpage)
 			iov_count = 1;