From: Hui Zhu <[email protected]> Add a comprehensive selftest suite for the `memcg_bpf_ops` functionality. These tests validate that BPF programs can correctly influence memory cgroup throttling behavior by implementing the new hooks.
The test suite is added in `prog_tests/memcg_ops.c` and covers several key scenarios: 1. `test_memcg_ops_over_high`: Verifies that a BPF program can trigger throttling on a low-priority cgroup by returning a delay from the `get_high_delay_ms` hook when a high-priority cgroup is under pressure. 2. `test_memcg_ops_below_low_over_high`: Tests the combination of the `below_low` and `get_high_delay_ms` hooks, ensuring they work together as expected. 3. `test_memcg_ops_below_min_over_high`: Validates the interaction between the `below_min` and `get_high_delay_ms` hooks. The test framework sets up a cgroup hierarchy with high and low priority groups, attaches BPF programs, runs memory-intensive workloads, and asserts that the observed throttling (measured by workload execution time) matches expectations. The BPF program (`progs/memcg_ops.c`) uses a tracepoint on `memcg:count_memcg_events` (specifically PGFAULT) to detect memory pressure and trigger the appropriate hooks in response. This test suite provides essential validation for the new memory control mechanisms. Signed-off-by: Geliang Tang <[email protected]> Signed-off-by: Hui Zhu <[email protected]> --- MAINTAINERS | 2 + .../selftests/bpf/prog_tests/memcg_ops.c | 537 ++++++++++++++++++ tools/testing/selftests/bpf/progs/memcg_ops.c | 129 +++++ 3 files changed, 668 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/memcg_ops.c create mode 100644 tools/testing/selftests/bpf/progs/memcg_ops.c diff --git a/MAINTAINERS b/MAINTAINERS index 491d567f7dc8..7e07bb330eae 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -6471,6 +6471,8 @@ F: mm/memcontrol-v1.h F: mm/page_counter.c F: mm/swap_cgroup.c F: samples/cgroup/* +F: tools/testing/selftests/bpf/prog_tests/memcg_ops.c +F: tools/testing/selftests/bpf/progs/memcg_ops.c F: tools/testing/selftests/cgroup/memcg_protection.m F: tools/testing/selftests/cgroup/test_hugetlb_memcg.c F: tools/testing/selftests/cgroup/test_kmem.c diff --git a/tools/testing/selftests/bpf/prog_tests/memcg_ops.c b/tools/testing/selftests/bpf/prog_tests/memcg_ops.c new file mode 100644 index 000000000000..9a8d16296f2d --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/memcg_ops.c @@ -0,0 +1,537 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Memory controller eBPF struct ops test + */ + +#include <test_progs.h> +#include <bpf/btf.h> +#include <sys/mman.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <unistd.h> +#include "cgroup_helpers.h" + +struct local_config { + u64 threshold; + u64 high_cgroup_id; + bool use_below_low; + bool use_below_min; + unsigned int over_high_ms; +} local_config; + +#include "memcg_ops.skel.h" + +#define TRIGGER_THRESHOLD 1 +#define OVER_HIGH_MS 2000 +#define FILE_SIZE (64 * 1024 * 1024ul) +#define BUFFER_SIZE (4096) +#define CG_LIMIT (120 * 1024 * 1024ul) + +#define CG_DIR "/memcg_ops_test" +#define CG_HIGH_DIR CG_DIR "/high" +#define CG_LOW_DIR CG_DIR "/low" + +static int +setup_cgroup(int *high_cgroup_id, int *low_cgroup_fd, int *high_cgroup_fd) +{ + int ret; + char limit_buf[20]; + + ret = setup_cgroup_environment(); + if (!ASSERT_OK(ret, "setup_cgroup_environment")) + goto cleanup; + + ret = create_and_get_cgroup(CG_DIR); + if (!ASSERT_GE(ret, 0, "create_and_get_cgroup "CG_DIR)) + goto cleanup; + close(ret); + ret = enable_controllers(CG_DIR, "memory"); + if (!ASSERT_OK(ret, "enable_controllers")) + goto cleanup; + snprintf(limit_buf, 20, "%ld", CG_LIMIT); + ret = write_cgroup_file(CG_DIR, "memory.max", limit_buf); + if (!ASSERT_OK(ret, "write_cgroup_file memory.max")) + goto cleanup; + ret = write_cgroup_file(CG_DIR, "memory.swap.max", "0"); + if (!ASSERT_OK(ret, "write_cgroup_file memory.swap.max")) + goto cleanup; + + ret = create_and_get_cgroup(CG_HIGH_DIR); + if (!ASSERT_GE(ret, 0, "create_and_get_cgroup "CG_HIGH_DIR)) + goto cleanup; + if (high_cgroup_fd) + *high_cgroup_fd = ret; + else + close(ret); + ret = (int)get_cgroup_id(CG_HIGH_DIR); + if (!ASSERT_GE(ret, 0, "get_cgroup_id")) + goto cleanup; + *high_cgroup_id = ret; + + ret = create_and_get_cgroup(CG_LOW_DIR); + if (!ASSERT_GE(ret, 0, "create_and_get_cgroup "CG_LOW_DIR)) + goto cleanup; + if (low_cgroup_fd) + *low_cgroup_fd = ret; + else + close(ret); + + return 0; + +cleanup: + cleanup_cgroup_environment(); + return -1; +} + +int write_file(const char *filename) +{ + int ret = -1; + size_t written = 0; + char *buffer; + FILE *fp; + + fp = fopen(filename, "wb"); + if (!fp) + goto out; + + buffer = malloc(BUFFER_SIZE); + if (!buffer) + goto cleanup_fp; + + memset(buffer, 'A', BUFFER_SIZE); + + while (written < FILE_SIZE) { + size_t to_write = (FILE_SIZE - written < BUFFER_SIZE) ? + (FILE_SIZE - written) : + BUFFER_SIZE; + + if (fwrite(buffer, 1, to_write, fp) != to_write) + goto cleanup; + written += to_write; + } + + ret = 0; +cleanup: + free(buffer); +cleanup_fp: + fclose(fp); +out: + return ret; +} + +int read_file(const char *filename, int iterations) +{ + int ret = -1; + long page_size = sysconf(_SC_PAGESIZE); + char *p; + char *map; + size_t i; + int fd; + struct stat sb; + + fd = open(filename, O_RDONLY); + if (fd == -1) + goto out; + + if (fstat(fd, &sb) == -1) + goto cleanup_fd; + + if (sb.st_size != FILE_SIZE) { + fprintf(stderr, "File size mismatch: expected %ld, got %ld\n", + FILE_SIZE, sb.st_size); + goto cleanup_fd; + } + + map = mmap(NULL, FILE_SIZE, PROT_READ, MAP_PRIVATE, fd, 0); + if (map == MAP_FAILED) + goto cleanup_fd; + + for (int iter = 0; iter < iterations; iter++) { + for (i = 0; i < FILE_SIZE; i += page_size) { + /* access a byte to trigger page fault */ + p = &map[i]; + __asm__ __volatile__("" : : "r"(p) : "memory"); + } + + if (env.verbosity >= VERBOSE_NORMAL) + printf("%s %d %d done\n", __func__, getpid(), iter); + } + + if (munmap(map, FILE_SIZE) == -1) + goto cleanup_fd; + + ret = 0; + +cleanup_fd: + close(fd); +out: + return ret; +} + +static void +real_test_memcg_ops_child_work(const char *cgroup_path, + char *data_filename, + char *time_filename, + int read_times) +{ + struct timeval start, end; + double elapsed; + FILE *fp; + + if (!ASSERT_OK(join_parent_cgroup(cgroup_path), "join_parent_cgroup")) + goto out; + + if (env.verbosity >= VERBOSE_NORMAL) + printf("%s %d begin\n", __func__, getpid()); + + gettimeofday(&start, NULL); + + if (!ASSERT_OK(write_file(data_filename), "write_file")) + goto out; + + if (env.verbosity >= VERBOSE_NORMAL) + printf("%s %d write_file done\n", __func__, getpid()); + + if (!ASSERT_OK(read_file(data_filename, read_times), "read_file")) + goto out; + + gettimeofday(&end, NULL); + + elapsed = (end.tv_sec - start.tv_sec) + + (end.tv_usec - start.tv_usec) / 1000000.0; + + if (env.verbosity >= VERBOSE_NORMAL) + printf("%s %d end %.6f\n", __func__, getpid(), elapsed); + + fp = fopen(time_filename, "w"); + if (!ASSERT_OK_PTR(fp, "fopen")) + goto out; + fprintf(fp, "%.6f", elapsed); + fclose(fp); + +out: + exit(0); +} + +static int get_time(char *time_filename, double *time) +{ + int ret = -1; + FILE *fp; + char buf[64]; + + fp = fopen(time_filename, "r"); + if (!ASSERT_OK_PTR(fp, "fopen")) + goto out; + + if (!ASSERT_OK_PTR(fgets(buf, sizeof(buf), fp), "fgets")) + goto cleanup; + + if (sscanf(buf, "%lf", time) < 0) { + PRINT_FAIL("sscanf %s", buf); + goto cleanup; + } + + ret = 0; +cleanup: + fclose(fp); +out: + return ret; +} + +static void real_test_memcg_ops(int read_times) +{ + int ret; + char data_file1[] = "/tmp/test_data_XXXXXX"; + char data_file2[] = "/tmp/test_data_XXXXXX"; + char time_file1[] = "/tmp/test_time_XXXXXX"; + char time_file2[] = "/tmp/test_time_XXXXXX"; + pid_t pid1, pid2; + double time1, time2; + + ret = mkstemp(data_file1); + if (!ASSERT_GT(ret, 0, "mkstemp")) + return; + close(ret); + ret = mkstemp(data_file2); + if (!ASSERT_GT(ret, 0, "mkstemp")) + goto cleanup_data_file1; + close(ret); + ret = mkstemp(time_file1); + if (!ASSERT_GT(ret, 0, "mkstemp")) + goto cleanup_data_file2; + close(ret); + ret = mkstemp(time_file2); + if (!ASSERT_GT(ret, 0, "mkstemp")) + goto cleanup_time_file1; + close(ret); + + pid1 = fork(); + if (!ASSERT_GE(pid1, 0, "fork")) + goto cleanup; + if (pid1 == 0) + real_test_memcg_ops_child_work(CG_LOW_DIR, + data_file1, + time_file1, + read_times); + + pid2 = fork(); + if (!ASSERT_GE(pid1, 0, "fork")) + goto cleanup; + if (pid2 == 0) + real_test_memcg_ops_child_work(CG_HIGH_DIR, + data_file2, + time_file2, + read_times); + + ret = waitpid(pid1, NULL, 0); + if (!ASSERT_GT(ret, 0, "waitpid")) + goto cleanup; + + ret = waitpid(pid2, NULL, 0); + if (!ASSERT_GT(ret, 0, "waitpid")) + goto cleanup; + + if (get_time(time_file1, &time1)) + goto cleanup; + + if (get_time(time_file2, &time2)) + goto cleanup; + + if (time1 < time2 || time1 - time2 <= 1) + PRINT_FAIL("low fast compare time1=%f, time2=%f", + time1, time2); + +cleanup: + unlink(time_file2); +cleanup_time_file1: + unlink(time_file1); +cleanup_data_file2: + unlink(data_file2); +cleanup_data_file1: + unlink(data_file1); +} + +void test_memcg_ops_over_high(void) +{ + int err, map_fd; + struct memcg_ops *skel; + struct bpf_map *map; + size_t bss_sz; + struct memcg_ops__bss *bss_data; + __u32 key = 0; + struct bpf_program *prog = NULL; + struct bpf_link *link = NULL, *link2 = NULL; + DECLARE_LIBBPF_OPTS(bpf_struct_ops_opts, opts); + int high_cgroup_id, low_cgroup_fd = -1; + + err = setup_cgroup(&high_cgroup_id, &low_cgroup_fd, NULL); + if (!ASSERT_OK(err, "setup_cgroup")) + goto out; + + skel = memcg_ops__open_and_load(); + if (!ASSERT_OK_PTR(skel, "memcg_ops__open_and_load")) + goto out; + + map = bpf_object__find_map_by_name(skel->obj, ".bss"); + if (!ASSERT_OK_PTR(map, "bpf_object__find_map_by_name .bss")) + goto out; + + map_fd = bpf_map__fd(map); + bss_sz = bpf_map__value_size(map); + bss_data = malloc(bpf_map__value_size(map)); + if (!ASSERT_OK_PTR(bss_data, "malloc(bpf_map__value_size(map))")) + goto out; + memset(bss_data, 0, sizeof(struct local_config)); + bss_data->local_config.high_cgroup_id = high_cgroup_id; + bss_data->local_config.threshold = TRIGGER_THRESHOLD; + bss_data->local_config.use_below_low = false; + bss_data->local_config.use_below_min = false; + bss_data->local_config.over_high_ms = OVER_HIGH_MS; + err = bpf_map_update_elem(map_fd, &key, bss_data, BPF_EXIST); + free(bss_data); + if (!ASSERT_OK(err, "bpf_map_update_elem")) + goto out; + + prog = bpf_object__find_program_by_name(skel->obj, + "handle_count_memcg_events"); + if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name")) + goto out; + + link = bpf_program__attach(prog); + if (!ASSERT_OK_PTR(link, "bpf_program__attach")) + goto out; + + map = bpf_object__find_map_by_name(skel->obj, "low_mcg_ops"); + if (!ASSERT_OK_PTR(map, "bpf_object__find_map_by_name low_mcg_ops")) + goto out; + + opts.relative_fd = low_cgroup_fd; + link2 = bpf_map__attach_struct_ops_opts(map, &opts); + if (!ASSERT_OK_PTR(link2, "bpf_map__attach_struct_ops_opts")) + goto out; + + real_test_memcg_ops(5); + +out: + bpf_link__destroy(link); + bpf_link__destroy(link2); + memcg_ops__detach(skel); + close(low_cgroup_fd); + cleanup_cgroup_environment(); +} + +void test_memcg_ops_below_low_over_high(void) +{ + int err, map_fd; + struct memcg_ops *skel; + struct bpf_map *map; + size_t bss_sz; + struct memcg_ops__bss *bss_data; + __u32 key = 0; + struct bpf_program *prog = NULL; + struct bpf_link *link = NULL, *link_high = NULL, *link_low = NULL; + DECLARE_LIBBPF_OPTS(bpf_struct_ops_opts, opts); + int high_cgroup_id, high_cgroup_fd = -1, low_cgroup_fd = -1; + + err = setup_cgroup(&high_cgroup_id, &low_cgroup_fd, &high_cgroup_fd); + if (!ASSERT_OK(err, "setup_cgroup")) + goto out; + + skel = memcg_ops__open_and_load(); + if (!ASSERT_OK_PTR(skel, "memcg_ops__open_and_load")) + goto out; + + map = bpf_object__find_map_by_name(skel->obj, ".bss"); + if (!ASSERT_OK_PTR(map, "bpf_object__find_map_by_name .bss")) + goto out; + + map_fd = bpf_map__fd(map); + bss_sz = bpf_map__value_size(map); + bss_data = malloc(bpf_map__value_size(map)); + if (!ASSERT_OK_PTR(bss_data, "malloc(bpf_map__value_size(map))")) + goto out; + memset(bss_data, 0, sizeof(struct local_config)); + bss_data->local_config.high_cgroup_id = high_cgroup_id; + bss_data->local_config.threshold = TRIGGER_THRESHOLD; + bss_data->local_config.use_below_low = true; + bss_data->local_config.use_below_min = false; + bss_data->local_config.over_high_ms = OVER_HIGH_MS; + err = bpf_map_update_elem(map_fd, &key, bss_data, BPF_EXIST); + free(bss_data); + if (!ASSERT_OK(err, "bpf_map_update_elem")) + goto out; + + prog = bpf_object__find_program_by_name(skel->obj, + "handle_count_memcg_events"); + if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name")) + goto out; + + link = bpf_program__attach(prog); + if (!ASSERT_OK_PTR(link, "bpf_program__attach")) + goto out; + + map = bpf_object__find_map_by_name(skel->obj, "high_mcg_ops"); + if (!ASSERT_OK_PTR(map, "bpf_object__find_map_by_name mcg_ops")) + goto out; + opts.relative_fd = high_cgroup_fd; + link_high = bpf_map__attach_struct_ops_opts(map, &opts); + if (!ASSERT_OK_PTR(link_high, "bpf_map__attach_struct_ops_opts")) + goto out; + + map = bpf_object__find_map_by_name(skel->obj, "low_mcg_ops"); + if (!ASSERT_OK_PTR(map, "bpf_object__find_map_by_name mcg_ops")) + goto out; + opts.relative_fd = low_cgroup_fd; + link_low = bpf_map__attach_struct_ops_opts(map, &opts); + if (!ASSERT_OK_PTR(link_low, "bpf_map__attach_struct_ops_opts")) + goto out; + + real_test_memcg_ops(50); + +out: + bpf_link__destroy(link); + bpf_link__destroy(link_high); + bpf_link__destroy(link_low); + memcg_ops__detach(skel); + close(high_cgroup_fd); + close(low_cgroup_fd); + cleanup_cgroup_environment(); +} + +void test_memcg_ops_below_min_over_high(void) +{ + int err, map_fd; + struct memcg_ops *skel; + struct bpf_map *map; + size_t bss_sz; + struct memcg_ops__bss *bss_data; + __u32 key = 0; + struct bpf_program *prog = NULL; + struct bpf_link *link = NULL, *link_high = NULL, *link_low = NULL; + DECLARE_LIBBPF_OPTS(bpf_struct_ops_opts, opts); + int high_cgroup_id, high_cgroup_fd = -1, low_cgroup_fd = -1; + + err = setup_cgroup(&high_cgroup_id, &low_cgroup_fd, &high_cgroup_fd); + if (!ASSERT_OK(err, "setup_cgroup")) + goto out; + + skel = memcg_ops__open_and_load(); + if (!ASSERT_OK_PTR(skel, "memcg_ops__open_and_load")) + goto out; + + map = bpf_object__find_map_by_name(skel->obj, ".bss"); + if (!ASSERT_OK_PTR(map, "bpf_object__find_map_by_name .bss")) + goto out; + + map_fd = bpf_map__fd(map); + bss_sz = bpf_map__value_size(map); + bss_data = malloc(bpf_map__value_size(map)); + if (!ASSERT_OK_PTR(bss_data, "malloc(bpf_map__value_size(map))")) + goto out; + memset(bss_data, 0, sizeof(struct local_config)); + bss_data->local_config.high_cgroup_id = high_cgroup_id; + bss_data->local_config.threshold = TRIGGER_THRESHOLD; + bss_data->local_config.use_below_low = false; + bss_data->local_config.use_below_min = true; + bss_data->local_config.over_high_ms = OVER_HIGH_MS; + err = bpf_map_update_elem(map_fd, &key, bss_data, BPF_EXIST); + free(bss_data); + if (!ASSERT_OK(err, "bpf_map_update_elem")) + goto out; + + prog = bpf_object__find_program_by_name(skel->obj, + "handle_count_memcg_events"); + if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name")) + goto out; + + link = bpf_program__attach(prog); + if (!ASSERT_OK_PTR(link, "bpf_program__attach")) + goto out; + + map = bpf_object__find_map_by_name(skel->obj, "high_mcg_ops"); + if (!ASSERT_OK_PTR(map, "bpf_object__find_map_by_name mcg_ops")) + goto out; + opts.relative_fd = high_cgroup_fd; + link_high = bpf_map__attach_struct_ops_opts(map, &opts); + if (!ASSERT_OK_PTR(link_high, "bpf_map__attach_struct_ops_opts")) + goto out; + + map = bpf_object__find_map_by_name(skel->obj, "low_mcg_ops"); + if (!ASSERT_OK_PTR(map, "bpf_object__find_map_by_name mcg_ops")) + goto out; + opts.relative_fd = low_cgroup_fd; + link_low = bpf_map__attach_struct_ops_opts(map, &opts); + if (!ASSERT_OK_PTR(link_low, "bpf_map__attach_struct_ops_opts")) + goto out; + + real_test_memcg_ops(50); + +out: + bpf_link__destroy(link); + bpf_link__destroy(link_high); + bpf_link__destroy(link_low); + memcg_ops__detach(skel); + close(high_cgroup_fd); + close(low_cgroup_fd); + cleanup_cgroup_environment(); +} diff --git a/tools/testing/selftests/bpf/progs/memcg_ops.c b/tools/testing/selftests/bpf/progs/memcg_ops.c new file mode 100644 index 000000000000..44087a206a61 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/memcg_ops.c @@ -0,0 +1,129 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "vmlinux.h" +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> + +#define ONE_SECOND_NS 1000000000 + +struct local_config { + u64 threshold; + u64 high_cgroup_id; + bool use_below_low; + bool use_below_min; + unsigned int over_high_ms; +} local_config; + +struct AggregationData { + u64 sum; + u64 window_start_ts; +}; + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, u32); + __type(value, struct AggregationData); +} aggregation_map SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, u32); + __type(value, u64); +} trigger_ts_map SEC(".maps"); + +SEC("tp/memcg/count_memcg_events") +int +handle_count_memcg_events(struct trace_event_raw_memcg_rstat_events *ctx) +{ + u32 key = 0; + struct AggregationData *data; + u64 current_ts; + + if (ctx->id != local_config.high_cgroup_id || + (ctx->item != PGFAULT)) + goto out; + + data = bpf_map_lookup_elem(&aggregation_map, &key); + if (!data) + goto out; + + current_ts = bpf_ktime_get_ns(); + + if (current_ts - data->window_start_ts < ONE_SECOND_NS) { + data->sum += ctx->val; + } else { + data->window_start_ts = current_ts; + data->sum = ctx->val; + } + + if (data->sum > local_config.threshold) { + bpf_map_update_elem(&trigger_ts_map, &key, ¤t_ts, + BPF_ANY); + data->sum = 0; + data->window_start_ts = current_ts; + } + +out: + return 0; +} + +static bool need_threshold(void) +{ + u32 key = 0; + u64 *trigger_ts; + bool ret = false; + + trigger_ts = bpf_map_lookup_elem(&trigger_ts_map, &key); + if (!trigger_ts || *trigger_ts == 0) + goto out; + + u64 current_ts = bpf_ktime_get_ns(); + + if (current_ts - *trigger_ts < ONE_SECOND_NS) + ret = true; + +out: + return ret; +} + +SEC("struct_ops/below_low") +unsigned int below_low_impl(struct mem_cgroup *memcg) +{ + if (!local_config.use_below_low) + return false; + + return need_threshold(); +} + +SEC("struct_ops/below_min") +unsigned int below_min_impl(struct mem_cgroup *memcg) +{ + if (!local_config.use_below_min) + return false; + + return need_threshold(); +} + +SEC("struct_ops/get_high_delay_ms") +unsigned int get_high_delay_ms_impl(struct mem_cgroup *memcg) +{ + if (local_config.over_high_ms && need_threshold()) + return local_config.over_high_ms; + + return 0; +} + +SEC(".struct_ops.link") +struct memcg_bpf_ops high_mcg_ops = { + .below_low = (void *)below_low_impl, + .below_min = (void *)below_min_impl, +}; + +SEC(".struct_ops.link") +struct memcg_bpf_ops low_mcg_ops = { + .get_high_delay_ms = (void *)get_high_delay_ms_impl, +}; + +char LICENSE[] SEC("license") = "GPL"; -- 2.43.0
