1 files changed, 88 insertions, 0 deletions
diff --git a/tools/testing/selftests/sched_ext/enq_select_cpu.c b/tools/testing/selftests/sched_ext/enq_select_cpu.c
new file mode 100644
index 000000000000..340c6f8b86da
--- /dev/null
+++ b/tools/testing/selftests/sched_ext/enq_select_cpu.c
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2023 Meta Platforms, Inc. and affiliates.
+ * Copyright (c) 2023 David Vernet <dvernet@meta.com>
+ * Copyright (c) 2023 Tejun Heo <tj@kernel.org>
+ */
+#include <bpf/bpf.h>
+#include <scx/common.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include "enq_select_cpu.bpf.skel.h"
+#include "scx_test.h"
+
+static enum scx_test_status setup(void **ctx)
+{
+	struct enq_select_cpu *skel;
+
+	skel = enq_select_cpu__open();
+	SCX_FAIL_IF(!skel, "Failed to open");
+	SCX_ENUM_INIT(skel);
+	SCX_FAIL_IF(enq_select_cpu__load(skel), "Failed to load skel");
+
+	*ctx = skel;
+
+	return SCX_TEST_PASS;
+}
+
+static int test_select_cpu_from_user(const struct enq_select_cpu *skel)
+{
+	int fd, ret;
+	__u64 args[1];
+
+	LIBBPF_OPTS(bpf_test_run_opts, attr,
+		.ctx_in = args,
+		.ctx_size_in = sizeof(args),
+	);
+
+	args[0] = getpid();
+	fd = bpf_program__fd(skel->progs.select_cpu_from_user);
+	if (fd < 0)
+		return fd;
+
+	ret = bpf_prog_test_run_opts(fd, &attr);
+	if (ret < 0)
+		return ret;
+
+	fprintf(stderr, "%s: CPU %d\n", __func__, attr.retval);
+
+	return 0;
+}
+
+static enum scx_test_status run(void *ctx)
+{
+	struct enq_select_cpu *skel = ctx;
+	struct bpf_link *link;
+
+	link = bpf_map__attach_struct_ops(skel->maps.enq_select_cpu_ops);
+	if (!link) {
+		SCX_ERR("Failed to attach scheduler");
+		return SCX_TEST_FAIL;
+	}
+
+	/* Pick an idle CPU from user-space */
+	SCX_FAIL_IF(test_select_cpu_from_user(skel), "Failed to pick idle CPU");
+
+	sleep(1);
+
+	SCX_EQ(skel->data->uei.kind, EXIT_KIND(SCX_EXIT_NONE));
+	bpf_link__destroy(link);
+
+	return SCX_TEST_PASS;
+}
+
+static void cleanup(void *ctx)
+{
+	struct enq_select_cpu *skel = ctx;
+
+	enq_select_cpu__destroy(skel);
+}
+
+struct scx_test enq_select_cpu = {
+	.name = "enq_select_cpu",
+	.description = "Verify scx_bpf_select_cpu_dfl() from multiple contexts",
+	.setup = setup,
+	.run = run,
+	.cleanup = cleanup,
+};
+REGISTER_SCX_TEST(&enq_select_cpu)