[PATCH] selftests: net: reuseport_bpf_numa: consider cpuless numa node

[Feng Tang <feng.tang@linux.alibaba.com>]

'reuseport_bpf_numa' case failed on a platform with CXL memory:

	#./reuseport_bpf_numa
	---- IPv4 UDP ----
	send node 0, receive socket 0
	./reuseport_bpf_numa: failed to pin to node: Invalid argument

The root cause is that platform has 2 numa nodes: node 0 has both
cpu and memory, while node 1 is a CXL node which only has memory,
which caused numa_run_on_node() failure.

Add check to skip cpuless numa node for the numa binding test.

Signed-off-by: Feng Tang <feng.tang@linux.alibaba.com>
---
 .../selftests/net/reuseport_bpf_numa.c        | 31 +++++++++++++++++--
 1 file changed, 28 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/net/reuseport_bpf_numa.c b/tools/testing/selftests/net/reuseport_bpf_numa.c
index 8ec52fc5ef41..197dbfc475f6 100644
--- a/tools/testing/selftests/net/reuseport_bpf_numa.c
+++ b/tools/testing/selftests/net/reuseport_bpf_numa.c
@@ -104,13 +104,35 @@ static void attach_bpf(int fd)
 	close(bpf_fd);
 }
 
-static void send_from_node(int node_id, int family, int proto)
+static inline bool is_cpuless_node(int node_id)
+{
+	struct bitmask *cpumask;
+	bool ret = false;
+
+	cpumask = numa_allocate_cpumask();
+
+	numa_node_to_cpus(node_id, cpumask);
+	if (!numa_bitmask_weight(cpumask))
+		ret = true;
+
+	numa_bitmask_free(cpumask);
+	return ret;
+}
+
+/*
+ * return -1 on node_id pointing to a cpuless node (like a CXL node),
+ * return 0 on successful numa setup
+ */
+static int send_from_node(int node_id, int family, int proto)
 {
 	struct sockaddr_storage saddr, daddr;
 	struct sockaddr_in  *saddr4, *daddr4;
 	struct sockaddr_in6 *saddr6, *daddr6;
 	int fd;
 
+	if (is_cpuless_node(node_id))
+		return -1;
+
 	switch (family) {
 	case AF_INET:
 		saddr4 = (struct sockaddr_in *)&saddr;
@@ -155,6 +177,7 @@ static void send_from_node(int node_id, int family, int proto)
 		error(1, errno, "failed to send message");
 
 	close(fd);
+	return 0;
 }
 
 static
@@ -213,7 +236,8 @@ static void test(int *rcv_fd, int len, int family, int proto)
 	for (node = 0; node < len; ++node) {
 		if (!numa_bitmask_isbitset(numa_nodes_ptr, node))
 			continue;
-		send_from_node(node, family, proto);
+		if (send_from_node(node, family, proto))
+			continue;
 		receive_on_node(rcv_fd, len, epfd, node, proto);
 	}
 
@@ -221,7 +245,8 @@ static void test(int *rcv_fd, int len, int family, int proto)
 	for (node = len - 1; node >= 0; --node) {
 		if (!numa_bitmask_isbitset(numa_nodes_ptr, node))
 			continue;
-		send_from_node(node, family, proto);
+		if (send_from_node(node, family, proto))
+			continue;
 		receive_on_node(rcv_fd, len, epfd, node, proto);
 	}
 
-- 
2.39.5 (Apple Git-154)