src/oom/test-oomd-util.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <unistd.h>
   4
   5 #include "alloc-util.h"
   6 #include "cgroup-setup.h"
   7 #include "cgroup-util.h"
   8 #include "fileio.h"
   9 #include "fs-util.h"
  10 #include "oomd-util.h"
  11 #include "parse-util.h"
  12 #include "path-util.h"
  13 #include "string-util.h"
  14 #include "strv.h"
  15 #include "tests.h"
  16
  17 static int fork_and_sleep(unsigned sleep_min) {
  18         usec_t n, timeout, ts;
  19
  20         pid_t pid = fork();
  21         assert_se(pid >= 0);
  22
  23         if (pid == 0) {
  24                 timeout = sleep_min * USEC_PER_MINUTE;
  25                 ts = now(CLOCK_MONOTONIC);
  26                 for (;;) {
  27                         n = now(CLOCK_MONOTONIC);
  28                         if (ts + timeout < n) {
  29                                 log_error("Child timed out waiting to be killed");
  30                                 abort();
  31                         }
  32                         sleep(1);
  33                 }
  34         }
  35
  36         return pid;
  37 }
  38
  39 static void test_oomd_cgroup_kill(void) {
  40         _cleanup_free_ char *cgroup_root = NULL, *cgroup = NULL;
  41         int pid[2];
  42         int r;
  43
  44         if (geteuid() != 0)
  45                 return (void) log_tests_skipped("not root");
  46
  47         if (cg_all_unified() <= 0)
  48                 return (void) log_tests_skipped("cgroups are not running in unified mode");
  49
  50         assert_se(cg_pid_get_path(NULL, 0, &cgroup_root) >= 0);
  51
  52         /* Create another cgroup below this one for the pids we forked off. We need this to be managed
  53          * by the test so that pid1 doesn't delete it before we can read the xattrs. */
  54         cgroup = path_join(cgroup_root, "oomdkilltest");
  55         assert_se(cgroup);
  56         assert_se(cg_create(SYSTEMD_CGROUP_CONTROLLER, cgroup) >= 0);
  57
  58         /* If we don't have permissions to set xattrs we're likely in a userns or missing capabilities */
  59         r = cg_set_xattr(SYSTEMD_CGROUP_CONTROLLER, cgroup, "user.oomd_test", "test", 4, 0);
  60         if (ERRNO_IS_PRIVILEGE(r) || ERRNO_IS_NOT_SUPPORTED(r))
  61                 return (void) log_tests_skipped("Cannot set user xattrs");
  62
  63         /* Do this twice to also check the increment behavior on the xattrs */
  64         for (int i = 0; i < 2; i++) {
  65                 _cleanup_free_ char *v = NULL;
  66
  67                 for (int j = 0; j < 2; j++) {
  68                         pid[j] = fork_and_sleep(5);
  69                         assert_se(cg_attach(SYSTEMD_CGROUP_CONTROLLER, cgroup, pid[j]) >= 0);
  70                 }
  71
  72                 r = oomd_cgroup_kill(cgroup, false /* recurse */, false /* dry run */);
  73                 if (r <= 0) {
  74                         log_debug_errno(r, "Failed to kill processes under %s: %m", cgroup);
  75                         abort();
  76                 }
  77
  78                 /* Wait a bit since processes may take some time to be cleaned up. */
  79                 sleep(2);
  80                 assert_se(cg_is_empty(SYSTEMD_CGROUP_CONTROLLER, cgroup) == true);
  81
  82                 assert_se(cg_get_xattr_malloc(SYSTEMD_CGROUP_CONTROLLER, cgroup, "user.oomd_kill", &v) >= 0);
  83                 assert_se(memcmp(v, i == 0 ? "2" : "4", 2) == 0);
  84         }
  85 }
  86
  87 static void test_oomd_cgroup_context_acquire_and_insert(void) {
  88         _cleanup_hashmap_free_ Hashmap *h1 = NULL, *h2 = NULL;
  89         _cleanup_(oomd_cgroup_context_freep) OomdCGroupContext *ctx = NULL;
  90         _cleanup_free_ char *cgroup = NULL;
  91         ManagedOOMPreference root_pref;
  92         OomdCGroupContext *c1, *c2;
  93         CGroupMask mask;
  94         bool test_xattrs;
  95         int root_xattrs, r;
  96
  97         if (geteuid() != 0)
  98                 return (void) log_tests_skipped("not root");
  99
 100         if (!is_pressure_supported())
 101                 return (void) log_tests_skipped("system does not support pressure");
 102
 103         if (cg_all_unified() <= 0)
 104                 return (void) log_tests_skipped("cgroups are not running in unified mode");
 105
 106         assert_se(cg_mask_supported(&mask) >= 0);
 107
 108         if (!FLAGS_SET(mask, CGROUP_MASK_MEMORY))
 109                 return (void) log_tests_skipped("cgroup memory controller is not available");
 110
 111         assert_se(cg_pid_get_path(NULL, 0, &cgroup) >= 0);
 112
 113         /* If we don't have permissions to set xattrs we're likely in a userns or missing capabilities
 114          * so skip the xattr portions of the test. */
 115         r = cg_set_xattr(SYSTEMD_CGROUP_CONTROLLER, cgroup, "user.oomd_test", "1", 1, 0);
 116         test_xattrs = !ERRNO_IS_PRIVILEGE(r) && !ERRNO_IS_NOT_SUPPORTED(r);
 117
 118         if (test_xattrs) {
 119                 assert_se(cg_set_xattr(SYSTEMD_CGROUP_CONTROLLER, cgroup, "user.oomd_omit", "1", 1, 0) >= 0);
 120                 assert_se(cg_set_xattr(SYSTEMD_CGROUP_CONTROLLER, cgroup, "user.oomd_avoid", "1", 1, 0) >= 0);
 121         }
 122
 123         assert_se(oomd_cgroup_context_acquire(cgroup, &ctx) == 0);
 124
 125         assert_se(streq(ctx->path, cgroup));
 126         assert_se(ctx->current_memory_usage > 0);
 127         assert_se(ctx->memory_min == 0);
 128         assert_se(ctx->memory_low == 0);
 129         assert_se(ctx->swap_usage == 0);
 130         assert_se(ctx->last_pgscan == 0);
 131         assert_se(ctx->pgscan == 0);
 132         /* omit takes precedence over avoid when both are set to true */
 133         if (test_xattrs)
 134                 assert_se(ctx->preference == MANAGED_OOM_PREFERENCE_OMIT);
 135         else
 136                 assert_se(ctx->preference == MANAGED_OOM_PREFERENCE_NONE);
 137         ctx = oomd_cgroup_context_free(ctx);
 138
 139         /* also check when only avoid is set to true */
 140         if (test_xattrs) {
 141                 assert_se(cg_set_xattr(SYSTEMD_CGROUP_CONTROLLER, cgroup, "user.oomd_omit", "0", 1, 0) >= 0);
 142                 assert_se(cg_set_xattr(SYSTEMD_CGROUP_CONTROLLER, cgroup, "user.oomd_avoid", "1", 1, 0) >= 0);
 143         }
 144         assert_se(oomd_cgroup_context_acquire(cgroup, &ctx) == 0);
 145         if (test_xattrs)
 146                 assert_se(ctx->preference == MANAGED_OOM_PREFERENCE_AVOID);
 147         ctx = oomd_cgroup_context_free(ctx);
 148
 149         /* Test the root cgroup */
 150         /* Root cgroup is live and not made on demand like the cgroup the test runs in. It can have varying
 151          * xattrs set already so let's read in the booleans first to get the final preference value. */
 152         root_xattrs = cg_get_xattr_bool(SYSTEMD_CGROUP_CONTROLLER, "", "user.oomd_omit");
 153         root_pref = root_xattrs > 0 ? MANAGED_OOM_PREFERENCE_OMIT : MANAGED_OOM_PREFERENCE_NONE;
 154         root_xattrs = cg_get_xattr_bool(SYSTEMD_CGROUP_CONTROLLER, "", "user.oomd_avoid");
 155         root_pref = root_xattrs > 0 ? MANAGED_OOM_PREFERENCE_AVOID : MANAGED_OOM_PREFERENCE_NONE;
 156         assert_se(oomd_cgroup_context_acquire("", &ctx) == 0);
 157         assert_se(streq(ctx->path, "/"));
 158         assert_se(ctx->current_memory_usage > 0);
 159         assert_se(ctx->preference == root_pref);
 160
 161         /* Test hashmap inserts */
 162         assert_se(h1 = hashmap_new(&oomd_cgroup_ctx_hash_ops));
 163         assert_se(oomd_insert_cgroup_context(NULL, h1, cgroup) == 0);
 164         c1 = hashmap_get(h1, cgroup);
 165         assert_se(c1);
 166         assert_se(oomd_insert_cgroup_context(NULL, h1, cgroup) == -EEXIST);
 167
 168          /* make sure certain values from h1 get updated in h2 */
 169         c1->pgscan = UINT64_MAX;
 170         c1->mem_pressure_limit = 6789;
 171         c1->mem_pressure_limit_hit_start = 42;
 172         c1->last_had_mem_reclaim = 888;
 173         assert_se(h2 = hashmap_new(&oomd_cgroup_ctx_hash_ops));
 174         assert_se(oomd_insert_cgroup_context(h1, h2, cgroup) == 0);
 175         c1 = hashmap_get(h1, cgroup);
 176         c2 = hashmap_get(h2, cgroup);
 177         assert_se(c1);
 178         assert_se(c2);
 179         assert_se(c1 != c2);
 180         assert_se(c2->last_pgscan == UINT64_MAX);
 181         assert_se(c2->mem_pressure_limit == 6789);
 182         assert_se(c2->mem_pressure_limit_hit_start == 42);
 183         assert_se(c2->last_had_mem_reclaim == 888); /* assumes the live pgscan is less than UINT64_MAX */
 184
 185         /* Assert that avoid/omit are not set if the cgroup is not owned by root */
 186         if (test_xattrs) {
 187                 ctx = oomd_cgroup_context_free(ctx);
 188                 assert_se(cg_set_access(SYSTEMD_CGROUP_CONTROLLER, cgroup, 65534, 0) >= 0);
 189                 assert_se(oomd_cgroup_context_acquire(cgroup, &ctx) == 0);
 190                 assert_se(ctx->preference == MANAGED_OOM_PREFERENCE_NONE);
 191         }
 192 }
 193
 194 static void test_oomd_update_cgroup_contexts_between_hashmaps(void) {
 195         _cleanup_hashmap_free_ Hashmap *h_old = NULL, *h_new = NULL;
 196         OomdCGroupContext *c_old, *c_new;
 197         char **paths = STRV_MAKE("/0.slice",
 198                                  "/1.slice");
 199
 200         OomdCGroupContext ctx_old[2] = {
 201                 { .path = paths[0],
 202                   .mem_pressure_limit = 5,
 203                   .mem_pressure_limit_hit_start = 777,
 204                   .last_had_mem_reclaim = 888,
 205                   .pgscan = 57 },
 206                 { .path = paths[1],
 207                   .mem_pressure_limit = 6,
 208                   .mem_pressure_limit_hit_start = 888,
 209                   .last_had_mem_reclaim = 888,
 210                   .pgscan = 42 },
 211         };
 212
 213         OomdCGroupContext ctx_new[2] = {
 214                 { .path = paths[0],
 215                   .pgscan = 57 },
 216                 { .path = paths[1],
 217                   .pgscan = 101 },
 218         };
 219
 220         assert_se(h_old = hashmap_new(&string_hash_ops));
 221         assert_se(hashmap_put(h_old, paths[0], &ctx_old[0]) >= 0);
 222         assert_se(hashmap_put(h_old, paths[1], &ctx_old[1]) >= 0);
 223
 224         assert_se(h_new = hashmap_new(&string_hash_ops));
 225         assert_se(hashmap_put(h_new, paths[0], &ctx_new[0]) >= 0);
 226         assert_se(hashmap_put(h_new, paths[1], &ctx_new[1]) >= 0);
 227
 228         oomd_update_cgroup_contexts_between_hashmaps(h_old, h_new);
 229
 230         assert_se(c_old = hashmap_get(h_old, "/0.slice"));
 231         assert_se(c_new = hashmap_get(h_new, "/0.slice"));
 232         assert_se(c_old->pgscan == c_new->last_pgscan);
 233         assert_se(c_old->mem_pressure_limit == c_new->mem_pressure_limit);
 234         assert_se(c_old->mem_pressure_limit_hit_start == c_new->mem_pressure_limit_hit_start);
 235         assert_se(c_old->last_had_mem_reclaim == c_new->last_had_mem_reclaim);
 236
 237         assert_se(c_old = hashmap_get(h_old, "/1.slice"));
 238         assert_se(c_new = hashmap_get(h_new, "/1.slice"));
 239         assert_se(c_old->pgscan == c_new->last_pgscan);
 240         assert_se(c_old->mem_pressure_limit == c_new->mem_pressure_limit);
 241         assert_se(c_old->mem_pressure_limit_hit_start == c_new->mem_pressure_limit_hit_start);
 242         assert_se(c_new->last_had_mem_reclaim > c_old->last_had_mem_reclaim);
 243 }
 244
 245 static void test_oomd_system_context_acquire(void) {
 246         _cleanup_(unlink_tempfilep) char path[] = "/oomdgetsysctxtestXXXXXX";
 247         OomdSystemContext ctx;
 248
 249         if (geteuid() != 0)
 250                 return (void) log_tests_skipped("not root");
 251
 252         assert_se(mkstemp(path));
 253
 254         assert_se(oomd_system_context_acquire("/verylikelynonexistentpath", &ctx) == -ENOENT);
 255
 256         assert_se(oomd_system_context_acquire(path, &ctx) == -EINVAL);
 257
 258         assert_se(write_string_file(path, "some\nwords\nacross\nmultiple\nlines", WRITE_STRING_FILE_CREATE) == 0);
 259         assert_se(oomd_system_context_acquire(path, &ctx) == -EINVAL);
 260
 261         assert_se(write_string_file(path, "MemTotal:       32495256 kB trailing\n"
 262                                           "MemFree:         9880512 kB data\n"
 263                                           "SwapTotal:       8388604 kB is\n"
 264                                           "SwapFree:           7604 kB bad\n", WRITE_STRING_FILE_CREATE) == 0);
 265         assert_se(oomd_system_context_acquire(path, &ctx) == -EINVAL);
 266
 267         assert_se(write_string_file(path, "MemTotal:       32495256 kB\n"
 268                                           "MemFree:         9880512 kB\n"
 269                                           "MemAvailable:   21777088 kB\n"
 270                                           "Buffers:            5968 kB\n"
 271                                           "Cached:         14344796 kB\n"
 272                                           "Unevictable:      740004 kB\n"
 273                                           "Mlocked:            4484 kB\n"
 274                                           "SwapTotal:       8388604 kB\n"
 275                                           "SwapFree:           7604 kB\n", WRITE_STRING_FILE_CREATE) == 0);
 276         assert_se(oomd_system_context_acquire(path, &ctx) == 0);
 277         assert_se(ctx.mem_total == 33275142144);
 278         assert_se(ctx.mem_used == 23157497856);
 279         assert_se(ctx.swap_total == 8589930496);
 280         assert_se(ctx.swap_used == 8582144000);
 281 }
 282
 283 static void test_oomd_pressure_above(void) {
 284         _cleanup_hashmap_free_ Hashmap *h1 = NULL, *h2 = NULL;
 285         _cleanup_set_free_ Set *t1 = NULL, *t2 = NULL, *t3 = NULL;
 286         OomdCGroupContext ctx[2], *c;
 287         loadavg_t threshold;
 288
 289         assert_se(store_loadavg_fixed_point(80, 0, &threshold) == 0);
 290
 291         /* /herp.slice */
 292         assert_se(store_loadavg_fixed_point(99, 99, &(ctx[0].memory_pressure.avg10)) == 0);
 293         assert_se(store_loadavg_fixed_point(99, 99, &(ctx[0].memory_pressure.avg60)) == 0);
 294         assert_se(store_loadavg_fixed_point(99, 99, &(ctx[0].memory_pressure.avg300)) == 0);
 295         ctx[0].mem_pressure_limit = threshold;
 296
 297         /* /derp.slice */
 298         assert_se(store_loadavg_fixed_point(1, 11, &(ctx[1].memory_pressure.avg10)) == 0);
 299         assert_se(store_loadavg_fixed_point(1, 11, &(ctx[1].memory_pressure.avg60)) == 0);
 300         assert_se(store_loadavg_fixed_point(1, 11, &(ctx[1].memory_pressure.avg300)) == 0);
 301         ctx[1].mem_pressure_limit = threshold;
 302
 303         /* High memory pressure */
 304         assert_se(h1 = hashmap_new(&string_hash_ops));
 305         assert_se(hashmap_put(h1, "/herp.slice", &ctx[0]) >= 0);
 306         assert_se(oomd_pressure_above(h1, 0 /* duration */, &t1) == 1);
 307         assert_se(set_contains(t1, &ctx[0]));
 308         assert_se(c = hashmap_get(h1, "/herp.slice"));
 309         assert_se(c->mem_pressure_limit_hit_start > 0);
 310
 311         /* Low memory pressure */
 312         assert_se(h2 = hashmap_new(&string_hash_ops));
 313         assert_se(hashmap_put(h2, "/derp.slice", &ctx[1]) >= 0);
 314         assert_se(oomd_pressure_above(h2, 0 /* duration */, &t2) == 0);
 315         assert_se(!t2);
 316         assert_se(c = hashmap_get(h2, "/derp.slice"));
 317         assert_se(c->mem_pressure_limit_hit_start == 0);
 318
 319         /* High memory pressure w/ multiple cgroups */
 320         assert_se(hashmap_put(h1, "/derp.slice", &ctx[1]) >= 0);
 321         assert_se(oomd_pressure_above(h1, 0 /* duration */, &t3) == 1);
 322         assert_se(set_contains(t3, &ctx[0]));
 323         assert_se(set_size(t3) == 1);
 324         assert_se(c = hashmap_get(h1, "/herp.slice"));
 325         assert_se(c->mem_pressure_limit_hit_start > 0);
 326         assert_se(c = hashmap_get(h1, "/derp.slice"));
 327         assert_se(c->mem_pressure_limit_hit_start == 0);
 328 }
 329
 330 static void test_oomd_mem_and_swap_free_below(void) {
 331         OomdSystemContext ctx = (OomdSystemContext) {
 332                 .mem_total = 20971512 * 1024U,
 333                 .mem_used = 3310136 * 1024U,
 334                 .swap_total = 20971512 * 1024U,
 335                 .swap_used = 20971440 * 1024U,
 336         };
 337         assert_se(oomd_mem_free_below(&ctx, 2000) == false);
 338         assert_se(oomd_swap_free_below(&ctx, 2000) == true);
 339
 340         ctx = (OomdSystemContext) {
 341                 .mem_total = 20971512 * 1024U,
 342                 .mem_used = 20971440 * 1024U,
 343                 .swap_total = 20971512 * 1024U,
 344                 .swap_used = 3310136 * 1024U,
 345         };
 346         assert_se(oomd_mem_free_below(&ctx, 2000) == true);
 347         assert_se(oomd_swap_free_below(&ctx, 2000) == false);
 348
 349         ctx = (OomdSystemContext) {
 350                 .mem_total = 0,
 351                 .mem_used = 0,
 352                 .swap_total = 0,
 353                 .swap_used = 0,
 354         };
 355         assert_se(oomd_mem_free_below(&ctx, 2000) == false);
 356         assert_se(oomd_swap_free_below(&ctx, 2000) == false);
 357 }
 358
 359 static void test_oomd_sort_cgroups(void) {
 360         _cleanup_hashmap_free_ Hashmap *h = NULL;
 361         _cleanup_free_ OomdCGroupContext **sorted_cgroups;
 362         char **paths = STRV_MAKE("/herp.slice",
 363                                  "/herp.slice/derp.scope",
 364                                  "/herp.slice/derp.scope/sheep.service",
 365                                  "/zupa.slice",
 366                                  "/boop.slice",
 367                                  "/omitted.slice",
 368                                  "/avoid.slice");
 369
 370         OomdCGroupContext ctx[7] = {
 371                 { .path = paths[0],
 372                   .swap_usage = 20,
 373                   .last_pgscan = 0,
 374                   .pgscan = 33,
 375                   .current_memory_usage = 10 },
 376                 { .path = paths[1],
 377                   .swap_usage = 60,
 378                   .last_pgscan = 33,
 379                   .pgscan = 1,
 380                   .current_memory_usage = 20 },
 381                 { .path = paths[2],
 382                   .swap_usage = 40,
 383                   .last_pgscan = 1,
 384                   .pgscan = 33,
 385                   .current_memory_usage = 40 },
 386                 { .path = paths[3],
 387                   .swap_usage = 10,
 388                   .last_pgscan = 33,
 389                   .pgscan = 2,
 390                   .current_memory_usage = 10 },
 391                 { .path = paths[4],
 392                   .swap_usage = 11,
 393                   .last_pgscan = 33,
 394                   .pgscan = 33,
 395                   .current_memory_usage = 10 },
 396                 { .path = paths[5],
 397                   .swap_usage = 90,
 398                   .last_pgscan = 0,
 399                   .pgscan = UINT64_MAX,
 400                   .preference = MANAGED_OOM_PREFERENCE_OMIT },
 401                 { .path = paths[6],
 402                   .swap_usage = 99,
 403                   .last_pgscan = 0,
 404                   .pgscan = UINT64_MAX,
 405                   .preference = MANAGED_OOM_PREFERENCE_AVOID },
 406         };
 407
 408         assert_se(h = hashmap_new(&string_hash_ops));
 409
 410         assert_se(hashmap_put(h, "/herp.slice", &ctx[0]) >= 0);
 411         assert_se(hashmap_put(h, "/herp.slice/derp.scope", &ctx[1]) >= 0);
 412         assert_se(hashmap_put(h, "/herp.slice/derp.scope/sheep.service", &ctx[2]) >= 0);
 413         assert_se(hashmap_put(h, "/zupa.slice", &ctx[3]) >= 0);
 414         assert_se(hashmap_put(h, "/boop.slice", &ctx[4]) >= 0);
 415         assert_se(hashmap_put(h, "/omitted.slice", &ctx[5]) >= 0);
 416         assert_se(hashmap_put(h, "/avoid.slice", &ctx[6]) >= 0);
 417
 418         assert_se(oomd_sort_cgroup_contexts(h, compare_swap_usage, NULL, &sorted_cgroups) == 6);
 419         assert_se(sorted_cgroups[0] == &ctx[1]);
 420         assert_se(sorted_cgroups[1] == &ctx[2]);
 421         assert_se(sorted_cgroups[2] == &ctx[0]);
 422         assert_se(sorted_cgroups[3] == &ctx[4]);
 423         assert_se(sorted_cgroups[4] == &ctx[3]);
 424         assert_se(sorted_cgroups[5] == &ctx[6]);
 425         sorted_cgroups = mfree(sorted_cgroups);
 426
 427         assert_se(oomd_sort_cgroup_contexts(h, compare_pgscan_rate_and_memory_usage, NULL, &sorted_cgroups) == 6);
 428         assert_se(sorted_cgroups[0] == &ctx[0]);
 429         assert_se(sorted_cgroups[1] == &ctx[2]);
 430         assert_se(sorted_cgroups[2] == &ctx[3]);
 431         assert_se(sorted_cgroups[3] == &ctx[1]);
 432         assert_se(sorted_cgroups[4] == &ctx[4]);
 433         assert_se(sorted_cgroups[5] == &ctx[6]);
 434         sorted_cgroups = mfree(sorted_cgroups);
 435
 436         assert_se(oomd_sort_cgroup_contexts(h, compare_pgscan_rate_and_memory_usage, "/herp.slice/derp.scope", &sorted_cgroups) == 2);
 437         assert_se(sorted_cgroups[0] == &ctx[2]);
 438         assert_se(sorted_cgroups[1] == &ctx[1]);
 439         assert_se(sorted_cgroups[2] == 0);
 440         assert_se(sorted_cgroups[3] == 0);
 441         assert_se(sorted_cgroups[4] == 0);
 442         assert_se(sorted_cgroups[5] == 0);
 443         assert_se(sorted_cgroups[6] == 0);
 444         sorted_cgroups = mfree(sorted_cgroups);
 445 }
 446
 447 int main(void) {
 448         int r;
 449
 450         test_setup_logging(LOG_DEBUG);
 451
 452         test_oomd_update_cgroup_contexts_between_hashmaps();
 453         test_oomd_system_context_acquire();
 454         test_oomd_pressure_above();
 455         test_oomd_mem_and_swap_free_below();
 456         test_oomd_sort_cgroups();
 457
 458         /* The following tests operate on live cgroups */
 459
 460         r = enter_cgroup_root(NULL);
 461         if (r < 0)
 462                 return log_tests_skipped_errno(r, "failed to enter a test cgroup scope");
 463
 464         test_oomd_cgroup_kill();
 465         test_oomd_cgroup_context_acquire_and_insert();
 466
 467         return 0;
 468 }