diff mbox series

[net-next] selftests/net: report rcv_mss in tcp_mmap

Message ID 20230731180846.1560539-1-willemdebruijn.kernel@gmail.com (mailing list archive)
State Accepted
Commit bd60438eeb1ebe9415b157398083b4910c7f0aa3
Delegated to: Netdev Maintainers
Headers show
Series [net-next] selftests/net: report rcv_mss in tcp_mmap | expand

Checks

Context Check Description
netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 9 this patch: 9
netdev/cc_maintainers warning 2 maintainers not CCed: shuah@kernel.org linux-kselftest@vger.kernel.org
netdev/build_clang success Errors and warnings before: 9 this patch: 9
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 9 this patch: 9
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 36 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Willem de Bruijn July 31, 2023, 6:08 p.m. UTC 
From: Willem de Bruijn <willemb@google.com>

tcp_mmap tests TCP_ZEROCOPY_RECEIVE. If 0% of data is received using
mmap, this may be due to mss. Report rcv_mss to identify this cause.

Output of a run failed due to too small mss:

    received 32768 MB (0 % mmap'ed) in 8.40458 s, 32.7057 Gbit
      cpu usage user:0.027922 sys:8.21126, 251.44 usec per MB, 3252 c-switches, rcv_mss 1428

Output on a successful run:

    received 32768 MB (99.9507 % mmap'ed) in 4.69023 s, 58.6064 Gbit
      cpu usage user:0.029172 sys:2.56105, 79.0473 usec per MB, 57591 c-switches, rcv_mss 4096

Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
---
 tools/testing/selftests/net/tcp_mmap.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

Comments

patchwork-bot+netdevbpf@kernel.org Aug. 2, 2023, 10:50 a.m. UTC | #1 
Hello:

This patch was applied to netdev/net-next.git (main)
by David S. Miller <davem@davemloft.net>:

On Mon, 31 Jul 2023 14:08:09 -0400 you wrote:
> From: Willem de Bruijn <willemb@google.com>
> 
> tcp_mmap tests TCP_ZEROCOPY_RECEIVE. If 0% of data is received using
> mmap, this may be due to mss. Report rcv_mss to identify this cause.
> 
> Output of a run failed due to too small mss:
> 
> [...]

Here is the summary with links:
  - [net-next] selftests/net: report rcv_mss in tcp_mmap
    https://git.kernel.org/netdev/net-next/c/bd60438eeb1e

You are awesome, thank you!
diff mbox series

Patch

diff --git a/tools/testing/selftests/net/tcp_mmap.c b/tools/testing/selftests/net/tcp_mmap.c
index 6e59b1461dcc..4fcce5150850 100644
--- a/tools/testing/selftests/net/tcp_mmap.c
+++ b/tools/testing/selftests/net/tcp_mmap.c
@@ -153,6 +153,19 @@  static void *mmap_large_buffer(size_t need, size_t *allocated)
 	return buffer;
 }
 
+static uint32_t tcp_info_get_rcv_mss(int fd)
+{
+	socklen_t sz = sizeof(struct tcp_info);
+	struct tcp_info info;
+
+	if (getsockopt(fd, IPPROTO_TCP, TCP_INFO, &info, &sz)) {
+		fprintf(stderr, "Error fetching TCP_INFO\n");
+		return 0;
+	}
+
+	return info.tcpi_rcv_mss;
+}
+
 void *child_thread(void *arg)
 {
 	unsigned char digest[SHA256_DIGEST_LENGTH];
@@ -288,7 +301,7 @@  void *child_thread(void *arg)
 		total_usec = 1000000*ru.ru_utime.tv_sec + ru.ru_utime.tv_usec +
 			     1000000*ru.ru_stime.tv_sec + ru.ru_stime.tv_usec;
 		printf("received %lg MB (%lg %% mmap'ed) in %lg s, %lg Gbit\n"
-		       "  cpu usage user:%lg sys:%lg, %lg usec per MB, %lu c-switches\n",
+		       "  cpu usage user:%lg sys:%lg, %lg usec per MB, %lu c-switches, rcv_mss %u\n",
 				total / (1024.0 * 1024.0),
 				100.0*total_mmap/total,
 				(double)delta_usec / 1000000.0,
@@ -296,7 +309,8 @@  void *child_thread(void *arg)
 				(double)ru.ru_utime.tv_sec + (double)ru.ru_utime.tv_usec / 1000000.0,
 				(double)ru.ru_stime.tv_sec + (double)ru.ru_stime.tv_usec / 1000000.0,
 				(double)total_usec/mb,
-				ru.ru_nvcsw);
+				ru.ru_nvcsw,
+				tcp_info_get_rcv_mss(fd));
 	}
 error:
 	munmap(buffer, buffer_sz);