Based on the work of Thomas Hellström to test dmem.max eviction, add a test for dmem.current usage after allocations and setting dmem.max.
Create a dmem cgroup, allocate close to capacity (or at most 4GiB), check current usage is within a small slack of the expected allocation. Then, set max to a small value and check allocations and current usage are limited to the max set. Set max to less than a single BO size, then check no allocations are allowed and current usage is also within the slack. After each allocation, release memory and check current usage has gone down. Signed-off-by: Thadeu Lima de Souza Cascardo <[email protected]> --- tests/cgroup_dmem.c | 251 +++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 246 insertions(+), 5 deletions(-) diff --git a/tests/cgroup_dmem.c b/tests/cgroup_dmem.c index 442c965f9bbf..fa4694b45035 100644 --- a/tests/cgroup_dmem.c +++ b/tests/cgroup_dmem.c @@ -1,6 +1,8 @@ // SPDX-License-Identifier: MIT /* * Copyright © 2025 Intel Corporation + * Copyright © 2026 Intel Corporation + * Copyright 2026 Valve Corporation */ /** @@ -17,10 +19,214 @@ * Test category: uapi */ +#include <errno.h> #include <inttypes.h> +#include <signal.h> +#include <stdatomic.h> +#include <stdint.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include "drmtest.h" #include "igt.h" +#include "igt_aux.h" #include "igt_cgroup.h" +#include "igt_dmem_driver.h" + +#define BO_SIZE SZ_64M +#define MAX_LIMIT ((uint64_t)4 * SZ_1G) +#define USAGE_SLACK SZ_4M /* tolerance above the set max */ +#define USAGE_POLL_MS 10 +#define USAGE_DROP_TIMEOUT_MS 1000 + +/** + * SUBTEST: simple + * DESCRIPTION: + * 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. + */ + +/** + * SUBTEST: current + * DESCRIPTION: + * Create a dmem cgroup, allocate close to capacity (or at most 4GiB), + * check current usage is within a small slack of the expected allocation. + * Then, set max to a small value and check allocations and current usage + * are limited to the max set. + * Set max to less than a single BO size, then check no allocations are allowed + * and current usage is also within the slack. + * After each allocation, release memory and check current usage has gone + * down. + * REQUIREMENTS: xe or amdgpu device with at least one VRAM region + */ + +static uint64_t wait_for_usage_drop(struct igt_cgroup *cg, const char *region, + uint64_t limit) +{ + uint64_t current; + unsigned int elapsed = 0; + + do { + igt_cgroup_dmem_get_current(cg, region, ¤t); + if (current <= limit) + return current; + usleep(USAGE_POLL_MS * 1000); + elapsed += USAGE_POLL_MS; + } while (elapsed < USAGE_DROP_TIMEOUT_MS); + + return current; +} + +static int allocate_vram(const struct igt_dmem_driver *drv, void *ctx, int fd, int max_bo, size_t len) +{ + int n_bo, err = 0; + for (n_bo = 0; n_bo < max_bo; n_bo++) { + err = drv->allocate_vram(ctx, n_bo, len); + if (err) + break; + } + /* These are expected failures we can ignore. */ + if (err == -ENOMEM || err == -ENOSPC) + err = 0; + return err ?: n_bo; +} + +static void free_vram(const struct igt_dmem_driver *drv, void *ctx, int max_bo) +{ + int i; + for (i = 0; i < max_bo; i++) + drv->free_vram(ctx, i); +} + +static void test_current(int fd, char *cg_region, unsigned int flags, const struct igt_dmem_driver *drv) +{ + struct igt_cgroup *cg; + void *ctx; + uint64_t current, capacity, cg_max; + int n_bo = 0, max_bo; + int err; + + igt_cgroup_dmem_get_capacity(cg_region, &capacity); + igt_require_f(capacity >= 4 * BO_SIZE, + "VRAM capacity (%"PRIu64" MiB) too small to test\n", + capacity / SZ_1M); + + /* + * Use up to 4 GiB, or the full capacity if the device has less. + * Leave one BO_SIZE worth of headroom so the device isn't completely + * exhausted before the cgroup limit is hit. + */ + cg_max = min(MAX_LIMIT, capacity - BO_SIZE - USAGE_SLACK); + cg_max = ALIGN_DOWN(cg_max, BO_SIZE); + + /* Create cgroup and move into it */ + cg = igt_cgroup_new("igt_cgroups_test"); + igt_cgroup_move_current(cg); + + max_bo = cg_max / BO_SIZE; + + err = drv->init(&ctx, fd, max_bo); + igt_assert_f(!err, "Failed to initialize driver"); + + n_bo = allocate_vram(drv, ctx, fd, max_bo, BO_SIZE); + igt_assert_f(n_bo > 0, "failed to allocate VRAM\n"); + + igt_cgroup_dmem_get_current(cg, cg_region, ¤t); + igt_debug("After fill: cgroup current = %"PRIu64" MiB, " + "max = %"PRIu64" MiB\n", + current / SZ_1M, cg_max / SZ_1M); + igt_assert_f(current < cg_max + USAGE_SLACK && current > cg_max - USAGE_SLACK, + "current usage (%"PRIu64" MiB) is not within margin of allocation (%"PRIu64" MiB)\n", + current / SZ_1M, cg_max / SZ_1M); + + free_vram(drv, ctx, n_bo); + wait_for_usage_drop(cg, cg_region, USAGE_SLACK); + + igt_cgroup_dmem_get_current(cg, cg_region, ¤t); + igt_debug("After free: cgroup current = %"PRIu64" MiB, " + "max = %"PRIu64" MiB\n", + current / SZ_1M, cg_max / SZ_1M); + igt_assert_f(current < USAGE_SLACK, + "current usage (%"PRIu64" MiB) is not within margin (%d MiB)\n", + current / SZ_1M, USAGE_SLACK / SZ_1M); + + /* Allow for a slack as there might be some extra pages allocated. */ + igt_cgroup_dmem_set_max(cg, cg_region, 2 * BO_SIZE + USAGE_SLACK, false); + + n_bo = allocate_vram(drv, ctx, fd, max_bo, BO_SIZE); + igt_assert_f(n_bo > 0, "failed to allocate VRAM\n"); + + igt_cgroup_dmem_get_current(cg, cg_region, ¤t); + igt_debug("After fill: cgroup current = %"PRIu64" MiB, " + "max = %"PRIu64" MiB\n", + current / SZ_1M, cg_max / SZ_1M); + igt_assert_f(current < 2 * BO_SIZE + USAGE_SLACK && current > 2 * BO_SIZE - USAGE_SLACK, + "current usage (%"PRIu64" MiB) is not within margin of allocation (%"PRIu64" MiB)\n", + current / SZ_1M, cg_max / SZ_1M); + + free_vram(drv, ctx, n_bo); + wait_for_usage_drop(cg, cg_region, USAGE_SLACK); + + igt_cgroup_dmem_get_current(cg, cg_region, ¤t); + igt_debug("After free: cgroup current = %"PRIu64" MiB, " + "max = %"PRIu64" MiB\n", + current / SZ_1M, cg_max / SZ_1M); + igt_assert_f(current < USAGE_SLACK, + "current usage (%"PRIu64" MiB) is not within margin (%d MiB)\n", + current / SZ_1M, USAGE_SLACK / SZ_1M); + + igt_cgroup_dmem_set_max(cg, cg_region, USAGE_SLACK, false); + + n_bo = allocate_vram(drv, ctx, fd, max_bo, BO_SIZE); + + /* + * amdgpu may succeed the allocation, by falling back to GTT, so no assertion here. + * Verify by reading current usage. + */ + + igt_cgroup_dmem_get_current(cg, cg_region, ¤t); + igt_debug("After fill: cgroup current = %"PRIu64" MiB, " + "max = %"PRIu64" MiB\n", + current / SZ_1M, cg_max / SZ_1M); + igt_assert_f(current < USAGE_SLACK, + "current usage (%"PRIu64" MiB) is not within margin\n", + current / SZ_1M); + + if (n_bo > 0) + free_vram(drv, ctx, n_bo); + wait_for_usage_drop(cg, cg_region, USAGE_SLACK); + + igt_cgroup_dmem_get_current(cg, cg_region, ¤t); + igt_debug("After free: cgroup current = %"PRIu64" MiB, " + "max = %"PRIu64" MiB\n", + current / SZ_1M, cg_max / SZ_1M); + igt_assert_f(current < USAGE_SLACK, + "current usage (%"PRIu64" MiB) is not within margin (%d MiB)\n", + current / SZ_1M, USAGE_SLACK / SZ_1M); + + drv->deinit(ctx); + igt_cgroup_free(cg); +} + +static const struct { + const char *name; + void (*test_fn)(int fd, char *cg_region, unsigned int flags, const struct igt_dmem_driver *drv); + unsigned int flags; +} subtests[] = { + { "current", test_current, 0 }, + { } +}; + +static const struct { + int driver_flag; + const struct igt_dmem_driver *driver; +} drivers[] = { + { DRIVER_XE, &xe_dmem_driver }, + { DRIVER_AMDGPU, &amdgpu_dmem_driver }, + { }, +}; IGT_TEST_DESCRIPTION("Exercises the cgroup v2 dmem controller interface."); @@ -32,7 +238,7 @@ static void fmt_bytes(uint64_t v, char *buf, size_t len) snprintf(buf, len, "%" PRIu64, v); } -int igt_simple_main() +static void simple_cgroup(void) { struct igt_cgroup *cg; const char *region; @@ -42,10 +248,6 @@ int igt_simple_main() 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"); @@ -90,3 +292,42 @@ int igt_simple_main() igt_cgroup_dmem_regions_free(regions); igt_cgroup_free(cg); } + +int igt_main() +{ + igt_fixture() { + igt_require_f(getuid() == 0, "Test requires root\n"); + /* Check dmem cgroup controller is available before doing anything else */ + igt_require_f(igt_cgroup_dmem_available(), + "dmem cgroup controller not available (no cgroup v2 or no registered regions)\n"); + + } + + igt_subtest("simple") + simple_cgroup(); + + for (int d = 0; drivers[d].driver; d++) { + igt_subtest_group() { + int fd = -1; + char *cg_region; + igt_fixture() { + fd = drm_open_driver(drivers[d].driver_flag); + igt_require_f(fd >= 0, + "No %s device found, skipping\n", + drivers[d].driver->name); + cg_region = drivers[d].driver->get_region_name(fd); + igt_require_f(cg_region, "Region not tracked by dmem cgroup controller\n"); + } + + for (int i = 0; subtests[i].name; i++) + igt_subtest_f("%s-%s", drivers[d].driver->name, subtests[i].name) + subtests[i].test_fn(fd, cg_region, subtests[i].flags, drivers[d].driver); + + igt_fixture() { + if (fd >= 0) + drm_close_driver(fd); + free(cg_region); + } + } + } +} -- 2.47.3
