workqueue: skip the node_nr_active update for non-unbound workqueuesgrafted

apply_wqattrs_commit() updates node_nr_active->max unconditionally.
wq->node_nr_active[] is only allocated for unbound workqueues, so guard
the call before per-cpu workqueues start using this path.

No functional change: only unbound workqueues reach apply_wqattrs_*()
today.

Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 100 insertions, 0 deletions

diff --git a/samples/bpf/sockex3_user.c b/samples/bpf/sockex3_user.c
new file mode 100644
index 000000000..56044acbd
--- /dev/null
+++ b/samples/bpf/sockex3_user.c
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <assert.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "sock_example.h"
+#include <unistd.h>
+#include <arpa/inet.h>
+
+struct flow_key_record {
+	__be32 src;
+	__be32 dst;
+	union {
+		__be32 ports;
+		__be16 port16[2];
+	};
+	__u32 ip_proto;
+};
+
+struct pair {
+	__u64 packets;
+	__u64 bytes;
+};
+
+int main(int argc, char **argv)
+{
+	int i, sock, fd, main_prog_fd, hash_map_fd;
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	char filename[256];
+	FILE *f;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	hash_map_fd = bpf_object__find_map_fd_by_name(obj, "hash_map");
+	if (hash_map_fd < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	/* find BPF main program */
+	main_prog_fd = 0;
+	bpf_object__for_each_program(prog, obj) {
+		fd = bpf_program__fd(prog);
+
+		if (!strcmp(bpf_program__name(prog), "main_prog"))
+			main_prog_fd = fd;
+	}
+
+	if (main_prog_fd == 0) {
+		fprintf(stderr, "ERROR: can't find main_prog\n");
+		goto cleanup;
+	}
+
+	sock = open_raw_sock("lo");
+
+	/* attach BPF program to socket */
+	assert(setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &main_prog_fd,
+			  sizeof(__u32)) == 0);
+
+	if (argc > 1)
+		f = popen("ping -4 -c5 localhost", "r");
+	else
+		f = popen("netperf -l 4 localhost", "r");
+	(void) f;
+
+	for (i = 0; i < 5; i++) {
+		struct flow_key_record key = {}, next_key;
+		struct pair value;
+
+		sleep(1);
+		printf("IP     src.port -> dst.port               bytes      packets\n");
+		while (bpf_map_get_next_key(hash_map_fd, &key, &next_key) == 0) {
+			bpf_map_lookup_elem(hash_map_fd, &next_key, &value);
+			printf("%s.%05d -> %s.%05d %12lld %12lld\n",
+			       inet_ntoa((struct in_addr){htonl(next_key.src)}),
+			       next_key.port16[0],
+			       inet_ntoa((struct in_addr){htonl(next_key.dst)}),
+			       next_key.port16[1],
+			       value.bytes, value.packets);
+			key = next_key;
+		}
+	}
+
+cleanup:
+	bpf_object__close(obj);
+	return 0;
+}