From: Thomas Hellström <[email protected]>
Add a test that exercises the cgroup v2 dmem controller interface using
the new igt_cgroup library.
The test uses igt_simple_main and:
- Skips if no dmem regions are registered (no cgroup v2 or no
dmem-capable device).
- Creates a sub-cgroup and moves the test process into it.
- Enumerates all registered device memory regions and prints their
capacity, system-wide current usage, per-cgroup current usage, and
configured min, low and max limits.
Assisted-by: GitHub Copilot:claude-sonnet-4.6
Signed-off-by: Thomas Hellström <[email protected]>
Signed-off-by: Thadeu Lima de Souza Cascardo <[email protected]>
---
tests/cgroup_dmem.c | 91 +++++++++++++++++++++++++++++++++++++++++++++++++++++
tests/meson.build | 1 +
2 files changed, 92 insertions(+)
diff --git a/tests/cgroup_dmem.c b/tests/cgroup_dmem.c
new file mode 100644
index 000000000000..2ccd8bdb00ae
--- /dev/null
+++ b/tests/cgroup_dmem.c
@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2025 Intel Corporation
+ */
+
+/**
+ * TEST: cgroup dmem
+ * Description: Exercises the cgroup v2 dmem controller interface. Creates a
+ * cgroup, moves the process into it, enumerates all dmem regions,
+ * prints their capacity, system-wide current usage, per-cgroup
+ * current usage and configured limits, then destroys the cgroup.
+ * Category: Core
+ * Mega feature: General Core features
+ * Sub-category: uapi
+ * Functionality: cgroup
+ * Feature: dmem
+ * Test category: uapi
+ */
+
+#include <inttypes.h>
+
+#include "igt.h"
+#include "igt_cgroup.h"
+
+IGT_TEST_DESCRIPTION("Exercises the cgroup v2 dmem controller interface.");
+
+static void fmt_bytes(uint64_t v, char *buf, size_t len)
+{
+ if (v == IGT_CGROUP_DMEM_MAX)
+ snprintf(buf, len, "max");
+ else
+ snprintf(buf, len, "%" PRIu64, v);
+}
+
+int igt_simple_main()
+{
+ struct igt_cgroup *cg;
+ const char *region;
+ char **regions;
+ uint64_t capacity, sys_current, cg_current, min, low, max;
+ char cap_s[32], sys_s[32], cg_s[32];
+ char min_s[32], low_s[32], max_s[32];
+ int i;
+
+ igt_require_f(igt_cgroup_dmem_available(),
+ "No dmem regions found; is cgroup v2 with the "
+ "dmem controller available?\n");
+
+ cg = igt_cgroup_new("igt-cgroup-dmem-test");
+ igt_assert_f(cg, "Failed to create cgroup\n");
+
+ igt_cgroup_move_current(cg);
+
+ regions = igt_cgroup_dmem_regions();
+ igt_assert_f(regions, "Failed to enumerate dmem regions\n");
+
+ igt_info("%-40s %16s %16s %16s %16s %16s %16s\n",
+ "region", "capacity", "system-current",
+ "cgroup-current", "min", "low", "max");
+ igt_info("%-40s %16s %16s %16s %16s %16s %16s\n",
+ "------", "--------", "--------------",
+ "--------------", "---", "---", "---");
+
+ for (i = 0; regions[i]; i++) {
+ region = regions[i];
+
+ igt_cgroup_dmem_get_capacity(region, &capacity);
+ fmt_bytes(capacity, cap_s, sizeof(cap_s));
+
+ igt_cgroup_dmem_get_system_current(region, &sys_current);
+ fmt_bytes(sys_current, sys_s, sizeof(sys_s));
+
+ igt_cgroup_dmem_get_current(cg, region, &cg_current);
+ fmt_bytes(cg_current, cg_s, sizeof(cg_s));
+
+ igt_cgroup_dmem_get_min(cg, region, &min);
+ fmt_bytes(min, min_s, sizeof(min_s));
+
+ igt_cgroup_dmem_get_low(cg, region, &low);
+ fmt_bytes(low, low_s, sizeof(low_s));
+
+ igt_cgroup_dmem_get_max(cg, region, &max);
+ fmt_bytes(max, max_s, sizeof(max_s));
+
+ igt_info("%-40s %16s %16s %16s %16s %16s %16s\n",
+ region, cap_s, sys_s, cg_s,
+ min_s, low_s, max_s);
+ }
+
+ igt_cgroup_dmem_regions_free(regions);
+}
diff --git a/tests/meson.build b/tests/meson.build
index 4f5c9be7b458..65b9a230f935 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -1,4 +1,5 @@
test_progs = [
+ 'cgroup_dmem',
'core_auth',
'core_debugfs',
'core_getclient',
