tools/testing/selftests/sched_ext/select_cpu_dfl.c

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright (c) 2023 Meta Platforms, Inc. and affiliates.
   4  * Copyright (c) 2023 David Vernet <[email protected]>
   5  * Copyright (c) 2023 Tejun Heo <[email protected]>
   6  */
   7 #include <bpf/bpf.h>
   8 #include <scx/common.h>
   9 #include <sys/wait.h>
  10 #include <unistd.h>
  11 #include "select_cpu_dfl.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_dfl *skel;
  19
  20         skel = select_cpu_dfl__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_dfl *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_dfl_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         SCX_ASSERT(!skel->bss->saw_local);
  51
  52         bpf_link__destroy(link);
  53
  54         return SCX_TEST_PASS;
  55 }
  56
  57 static void cleanup(void *ctx)
  58 {
  59         struct select_cpu_dfl *skel = ctx;
  60
  61         select_cpu_dfl__destroy(skel);
  62 }
  63
  64 struct scx_test select_cpu_dfl = {
  65         .name = "select_cpu_dfl",
  66         .description = "Verify the default ops.select_cpu() dispatches tasks "
  67                        "when idles cores are found, and skips ops.enqueue()",
  68         .setup = setup,
  69         .run = run,
  70         .cleanup = cleanup,
  71 };
  72 REGISTER_SCX_TEST(&select_cpu_dfl)