tools/testing/selftests/sched_ext/select_cpu_dispatch.c

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright (c) 2023 Meta Platforms, Inc. and affiliates.
   4  * Copyright (c) 2023 David Vernet <dvernet@meta.com>
   5  * Copyright (c) 2023 Tejun Heo <tj@kernel.org>
   6  */
   7 #include <bpf/bpf.h>
   8 #include <scx/common.h>
   9 #include <sys/wait.h>
  10 #include <unistd.h>
  11 #include "select_cpu_dispatch.bpf.skel.h"
  12 #include "scx_test.h"
  13
  14 #define NUM_CHILDREN 1028
  15
  16 static enum scx_test_status setup(void **ctx)
  17 {
  18         struct select_cpu_dispatch *skel;
  19
  20         skel = select_cpu_dispatch__open_and_load();
  21         SCX_FAIL_IF(!skel, "Failed to open and load skel");
  22         *ctx = skel;
  23
  24         return SCX_TEST_PASS;
  25 }
  26
  27 static enum scx_test_status run(void *ctx)
  28 {
  29         struct select_cpu_dispatch *skel = ctx;
  30         struct bpf_link *link;
  31         pid_t pids[NUM_CHILDREN];
  32         int i, status;
  33
  34         link = bpf_map__attach_struct_ops(skel->maps.select_cpu_dispatch_ops);
  35         SCX_FAIL_IF(!link, "Failed to attach scheduler");
  36
  37         for (i = 0; i < NUM_CHILDREN; i++) {
  38                 pids[i] = fork();
  39                 if (pids[i] == 0) {
  40                         sleep(1);
  41                         exit(0);
  42                 }
  43         }
  44
  45         for (i = 0; i < NUM_CHILDREN; i++) {
  46                 SCX_EQ(waitpid(pids[i], &status, 0), pids[i]);
  47                 SCX_EQ(status, 0);
  48         }
  49
  50         bpf_link__destroy(link);
  51
  52         return SCX_TEST_PASS;
  53 }
  54
  55 static void cleanup(void *ctx)
  56 {
  57         struct select_cpu_dispatch *skel = ctx;
  58
  59         select_cpu_dispatch__destroy(skel);
  60 }
  61
  62 struct scx_test select_cpu_dispatch = {
  63         .name = "select_cpu_dispatch",
  64         .description = "Test direct dispatching to built-in DSQs from "
  65                        "ops.select_cpu()",
  66         .setup = setup,
  67         .run = run,
  68         .cleanup = cleanup,
  69 };
  70 REGISTER_SCX_TEST(&select_cpu_dispatch)