patch 'app/testpmd: stop forwarding in secondary process' has been queued to stable release 24.11.4

[Kevin Traynor]

Hi,

FYI, your patch has been queued to stable release 24.11.4

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 11/05/25. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/kevintraynor/dpdk-stable

This queued commit can be viewed at:
https://github.com/kevintraynor/dpdk-stable/commit/a5c12c892dd18ff8d37dcf7f1ad28a7de49f29a3

Thanks.

Kevin

---
>From a5c12c892dd18ff8d37dcf7f1ad28a7de49f29a3 Mon Sep 17 00:00:00 2001
From: Khadem Ullah <14pwcse1224 at uetpeshawar.edu.pk>
Date: Wed, 17 Sep 2025 23:47:03 -0700
Subject: [PATCH] app/testpmd: stop forwarding in secondary process

[ upstream commit f96273c8e9d39e472bb07acc05e493b1e712e51b ]

When the secondary process testpmd application running any fwd_engine
and after that primary has exited will cause a crash.

This patch forces secondary process forwarding lcores
in fwd_engine to stop before the primary process exits.

Fixes: a550baf24af90f ("app/testpmd: support multi-process")

Signed-off-by: Khadem Ullah <14pwcse1224 at uetpeshawar.edu.pk>
Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
---
 app/test-pmd/testpmd.c | 103 +++++++++++++++++++++++++++++++++++++++--
 1 file changed, 99 insertions(+), 4 deletions(-)

diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
index 5aaf6534e3..0fb18abe79 100644
--- a/app/test-pmd/testpmd.c
+++ b/app/test-pmd/testpmd.c
@@ -3568,4 +3568,81 @@ detach_devargs(char *identifier)
 }
 
+#ifndef RTE_EXEC_ENV_WINDOWS
+
+enum testpmd_req_type {
+	TESTPMD_REQ_TYPE_EXIT,
+};
+
+struct testpmd_mp_req {
+	enum testpmd_req_type t;
+};
+
+struct testpmd_mp_resp {
+	int result;
+};
+
+#define TESTPMD_MP	"mp_testpmd"
+
+/* Send reply to this peer when testpmd exits */
+static RTE_ATOMIC(const char *) primary_name;
+
+static void
+reply_to_primary(const char *peer, int result)
+{
+	struct rte_mp_msg reply = { };
+	struct testpmd_mp_resp *resp = (struct testpmd_mp_resp *) &reply.param;
+
+	strlcpy(reply.name, TESTPMD_MP, RTE_MP_MAX_NAME_LEN);
+	reply.len_param = sizeof(*resp);
+	resp->result = result;
+
+	printf("Replying %d to primary\n", result);
+	fflush(stdout);
+
+	if (rte_mp_reply(&reply, peer) < 0)
+		printf("Failed to send response to primary:%s", strerror(rte_errno));
+}
+
+/* Primary process is exiting, stop secondary process */
+static void
+pmd_notify_secondary(void)
+{
+	struct testpmd_mp_req request = {
+		.t = TESTPMD_REQ_TYPE_EXIT,
+	};
+	struct rte_mp_msg mp_req = {
+		.name = TESTPMD_MP,
+		.len_param = sizeof(request),
+	};
+	struct rte_mp_reply reply;
+	struct timespec ts = {.tv_sec = 5, .tv_nsec = 0};
+
+	printf("\nPrimary: Sending 'stop_req' request to secondary...\n");
+	fflush(stdout);
+
+	memcpy(mp_req.param, &request, sizeof(request));
+	rte_mp_request_sync(&mp_req, &reply, &ts);
+}
+
+static int
+handle_testpmd_request(const struct rte_mp_msg *request, const void *peer)
+{
+	const struct testpmd_mp_req *req = (const struct testpmd_mp_req *)request->param;
+
+	if (req->t == TESTPMD_REQ_TYPE_EXIT) {
+		printf("\nReceived notification of primary exiting\n");
+		fflush(stdout);
+
+		/* Response is sent after forwarding loop exits */
+		rte_atomic_store_explicit(&primary_name, peer, rte_memory_order_relaxed);
+
+		kill(getpid(), SIGINT);
+	} else {
+		reply_to_primary(peer, -EINVAL);
+	}
+	return 0;
+}
+#endif
+
 void
 pmd_test_exit(void)
@@ -3579,4 +3656,8 @@ pmd_test_exit(void)
 
 #ifndef RTE_EXEC_ENV_WINDOWS
+	/* Tell secondary to exit */
+	if (rte_eal_process_type() == RTE_PROC_PRIMARY)
+		pmd_notify_secondary();
+
 	for (i = 0 ; i < RTE_DIM(mempools) ; i++) {
 		if (mempools[i]) {
@@ -4359,7 +4440,10 @@ main(int argc, char** argv)
 
 #ifndef RTE_EXEC_ENV_WINDOWS
-	if (rte_eal_process_type() == RTE_PROC_SECONDARY &&
-	    enable_primary_monitor() < 0)
-		rte_exit(EXIT_FAILURE, "Cannot setup primary monitor");
+	if (rte_eal_process_type() == RTE_PROC_SECONDARY) {
+		if (enable_primary_monitor() < 0)
+			rte_exit(EXIT_FAILURE, "Cannot setup primary monitor");
+		if (rte_mp_action_register(TESTPMD_MP, handle_testpmd_request) < 0)
+			rte_exit(EXIT_FAILURE, "Failed to register message action\n");
+	}
 #endif
 
@@ -4558,10 +4642,21 @@ main(int argc, char** argv)
 
 #ifndef RTE_EXEC_ENV_WINDOWS
-	if (rte_eal_process_type() == RTE_PROC_SECONDARY)
+	if (rte_eal_process_type() == RTE_PROC_SECONDARY) {
 		disable_primary_monitor();
+		rte_mp_action_unregister(TESTPMD_MP);
+	}
 #endif
 
 	pmd_test_exit();
 
+#ifndef RTE_EXEC_ENV_WINDOWS
+	if (rte_eal_process_type() == RTE_PROC_SECONDARY) {
+		const char *peer = rte_atomic_exchange_explicit(&primary_name, NULL,
+				rte_memory_order_relaxed);
+		if (peer)
+			reply_to_primary(peer, 0);
+	}
+#endif
+
 #ifdef RTE_LIB_PDUMP
 	/* uninitialize packet capture framework */
-- 
2.51.0

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2025-10-31 13:53:55.192085490 +0000
+++ 0097-app-testpmd-stop-forwarding-in-secondary-process.patch	2025-10-31 13:53:52.274524111 +0000
@@ -1 +1 @@
-From f96273c8e9d39e472bb07acc05e493b1e712e51b Mon Sep 17 00:00:00 2001
+From a5c12c892dd18ff8d37dcf7f1ad28a7de49f29a3 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit f96273c8e9d39e472bb07acc05e493b1e712e51b ]
+
@@ -13 +14,0 @@
-Cc: stable at dpdk.org
@@ -22 +23 @@
-index 1a48b00e93..2360da3a48 100644
+index 5aaf6534e3..0fb18abe79 100644
@@ -25 +26 @@
-@@ -3611,4 +3611,81 @@ detach_devargs(char *identifier)
+@@ -3568,4 +3568,81 @@ detach_devargs(char *identifier)
@@ -107 +108 @@
-@@ -3622,4 +3699,8 @@ pmd_test_exit(void)
+@@ -3579,4 +3656,8 @@ pmd_test_exit(void)
@@ -116 +117 @@
-@@ -4431,7 +4512,10 @@ main(int argc, char** argv)
+@@ -4359,7 +4440,10 @@ main(int argc, char** argv)
@@ -130 +131 @@
-@@ -4635,10 +4719,21 @@ main(int argc, char** argv)
+@@ -4558,10 +4642,21 @@ main(int argc, char** argv)