scx: Add a selftest for creating and destroying a DSQ

tools/testing/selftests/sched_ext/Makefile

@@ -161,6 +161,7 @@ endef
 all_test_bpfprogs := $(foreach prog,$(wildcard *.bpf.c),$(INCLUDE_DIR)/$(patsubst %.c,%.skel.h,$(prog)))
 
 auto-test-targets :=			\
+	create_dsq			\
 	enq_last_no_enq_fails		\
 	enq_select_cpu_fails		\
 	ddsp_bogus_dsq_fail		\

tools/testing/selftests/sched_ext/create_dsq.bpf.c

@@ -0,0 +1,58 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Create and destroy DSQs in a loop.
+ *
+ * Copyright (c) 2024 Meta Platforms, Inc. and affiliates.
+ * Copyright (c) 2024 David Vernet <[email protected]>
+ */
+
+#include <scx/common.bpf.h>
+
+char _license[] SEC("license") = "GPL";
+
+void BPF_STRUCT_OPS(create_dsq_exit_task, struct task_struct *p,
+		    struct scx_exit_task_args *args)
+{
+	scx_bpf_destroy_dsq(p->pid);
+}
+
+s32 BPF_STRUCT_OPS_SLEEPABLE(create_dsq_init_task, struct task_struct *p,
+			     struct scx_init_task_args *args)
+{
+	s32 err;
+
+	err = scx_bpf_create_dsq(p->pid, -1);
+	if (err)
+		scx_bpf_error("Failed to create DSQ for %s[%d]",
+			      p->comm, p->pid);
+
+	return err;
+}
+
+s32 BPF_STRUCT_OPS_SLEEPABLE(create_dsq_init)
+{
+	u32 i;
+	s32 err;
+
+	bpf_for(i, 0, 1024) {
+		err = scx_bpf_create_dsq(i, -1);
+		if (err) {
+			scx_bpf_error("Failed to create DSQ %d", i);
+			return 0;
+		}
+	}
+
+	bpf_for(i, 0, 1024) {
+		scx_bpf_destroy_dsq(i);
+	}
+
+	return 0;
+}
+
+SEC(".struct_ops.link")
+struct sched_ext_ops create_dsq_ops = {
+	.init_task		= create_dsq_init_task,
+	.exit_task		= create_dsq_exit_task,
+	.init			= create_dsq_init,
+	.name			= "create_dsq",
+};

tools/testing/selftests/sched_ext/create_dsq.c

@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2024 Meta Platforms, Inc. and affiliates.
+ * Copyright (c) 2024 David Vernet <[email protected]>
+ */
+#include <bpf/bpf.h>
+#include <scx/common.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include "create_dsq.bpf.skel.h"
+#include "scx_test.h"
+
+static enum scx_test_status setup(void **ctx)
+{
+	struct create_dsq *skel;
+
+	skel = create_dsq__open_and_load();
+	if (!skel) {
+		SCX_ERR("Failed to open and load skel");
+		return SCX_TEST_FAIL;
+	}
+	*ctx = skel;
+
+	return SCX_TEST_PASS;
+}
+
+static enum scx_test_status run(void *ctx)
+{
+	struct create_dsq *skel = ctx;
+	struct bpf_link *link;
+
+	link = bpf_map__attach_struct_ops(skel->maps.create_dsq_ops);
+	if (!link) {
+		SCX_ERR("Failed to attach scheduler");
+		return SCX_TEST_FAIL;
+	}
+
+	bpf_link__destroy(link);
+
+	return SCX_TEST_PASS;
+}
+
+static void cleanup(void *ctx)
+{
+	struct create_dsq *skel = ctx;
+
+	create_dsq__destroy(skel);
+}
+
+struct scx_test create_dsq = {
+	.name = "create_dsq",
+	.description = "Create and destroy a dsq in a loop",
+	.setup = setup,
+	.run = run,
+	.cleanup = cleanup,
+};
+REGISTER_SCX_TEST(&create_dsq)