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From: Jakub Kicinski <kuba@kernel.org>
To: davem@davemloft.net
Cc: netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com,
	Jakub Kicinski <kuba@kernel.org>,
	shuah@kernel.org, linux-kselftest@vger.kernel.org
Subject: [PATCH net-next 1/2] selftests: net: fix timestamp not arriving in cmsg_time.sh
Date: Thu,  9 May 2024 17:57:04 -0700	[thread overview]
Message-ID: <20240510005705.43069-1-kuba@kernel.org> (raw)

On slow machines the SND timestamp sometimes doesn't arrive before
we quit. The test only waits as long as the packet delay, so it's
easy for a race condition to happen.

Double the wait but do a bit of polling, once the SND timestamp
arrives there's no point to wait any longer.

This fixes the "TXTIME abs" failures on debug kernels, like:

   Case ICMPv4  - TXTIME abs returned '', expected 'OK'

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
CC: shuah@kernel.org
CC: linux-kselftest@vger.kernel.org
---
 tools/testing/selftests/net/cmsg_sender.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/net/cmsg_sender.c b/tools/testing/selftests/net/cmsg_sender.c
index c79e65581dc3..f25268504937 100644
--- a/tools/testing/selftests/net/cmsg_sender.c
+++ b/tools/testing/selftests/net/cmsg_sender.c
@@ -333,16 +333,17 @@ static const char *cs_ts_info2str(unsigned int info)
 	return "unknown";
 }
 
-static void
+static unsigned long
 cs_read_cmsg(int fd, struct msghdr *msg, char *cbuf, size_t cbuf_sz)
 {
 	struct sock_extended_err *see;
 	struct scm_timestamping *ts;
+	unsigned int ts_seen = 0;
 	struct cmsghdr *cmsg;
 	int i, err;
 
 	if (!opt.ts.ena)
-		return;
+		return 0;
 	msg->msg_control = cbuf;
 	msg->msg_controllen = cbuf_sz;
 
@@ -396,8 +397,11 @@ cs_read_cmsg(int fd, struct msghdr *msg, char *cbuf, size_t cbuf_sz)
 			printf(" %5s ts%d %lluus\n",
 			       cs_ts_info2str(see->ee_info),
 			       i, rel_time);
+			ts_seen |= 1 << see->ee_info;
 		}
 	}
+
+	return ts_seen;
 }
 
 static void ca_set_sockopts(int fd)
@@ -509,10 +513,16 @@ int main(int argc, char *argv[])
 	err = ERN_SUCCESS;
 
 	if (opt.ts.ena) {
-		/* Make sure all timestamps have time to loop back */
-		usleep(opt.txtime.delay);
+		unsigned long seen;
+		int i;
 
-		cs_read_cmsg(fd, &msg, cbuf, sizeof(cbuf));
+		/* Make sure all timestamps have time to loop back */
+		for (i = 0; i < 40; i++) {
+			seen = cs_read_cmsg(fd, &msg, cbuf, sizeof(cbuf));
+			if (seen & (1 << SCM_TSTAMP_SND))
+				break;
+			usleep(opt.txtime.delay / 20);
+		}
 	}
 
 err_out:
-- 
2.45.0


             reply	other threads:[~2024-05-10  0:58 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-05-10  0:57 Jakub Kicinski [this message]
2024-05-10  0:57 ` [PATCH net-next 2/2] selftests: net: increase the delay for relative cmsg_time.sh test Jakub Kicinski
2024-05-10  2:25   ` Willem de Bruijn
2024-05-10  2:49 ` [PATCH net-next 1/2] selftests: net: fix timestamp not arriving in cmsg_time.sh Willem de Bruijn
2024-05-11  1:23   ` Jakub Kicinski
2024-05-11  1:30 ` patchwork-bot+netdevbpf

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