This patch add a new kselftest to demonstrate and verify the new hugetlb memcg accounting behavior. Signed-off-by: Nhat Pham <nphamcs@xxxxxxxxx> --- MAINTAINERS | 2 + tools/testing/selftests/cgroup/.gitignore | 1 + tools/testing/selftests/cgroup/Makefile | 2 + .../selftests/cgroup/test_hugetlb_memcg.c | 222 ++++++++++++++++++ 4 files changed, 227 insertions(+) create mode 100644 tools/testing/selftests/cgroup/test_hugetlb_memcg.c diff --git a/MAINTAINERS b/MAINTAINERS index bf0f54c24f81..ce9f40bcc2ba 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5269,6 +5269,7 @@ S: Maintained F: mm/memcontrol.c F: mm/swap_cgroup.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 F: tools/testing/selftests/cgroup/test_memcontrol.c @@ -9652,6 +9653,7 @@ F: include/linux/hugetlb.h F: mm/hugetlb.c F: mm/hugetlb_vmemmap.c F: mm/hugetlb_vmemmap.h +F: tools/testing/selftests/cgroup/test_hugetlb_memcg.c HVA ST MEDIA DRIVER M: Jean-Christophe Trotin <jean-christophe.trotin@xxxxxxxxxxx> diff --git a/tools/testing/selftests/cgroup/.gitignore b/tools/testing/selftests/cgroup/.gitignore index af8c3f30b9c1..2732e0b29271 100644 --- a/tools/testing/selftests/cgroup/.gitignore +++ b/tools/testing/selftests/cgroup/.gitignore @@ -7,4 +7,5 @@ test_kill test_cpu test_cpuset test_zswap +test_hugetlb_memcg wait_inotify diff --git a/tools/testing/selftests/cgroup/Makefile b/tools/testing/selftests/cgroup/Makefile index c27f05f6ce9b..00b441928909 100644 --- a/tools/testing/selftests/cgroup/Makefile +++ b/tools/testing/selftests/cgroup/Makefile @@ -14,6 +14,7 @@ TEST_GEN_PROGS += test_kill TEST_GEN_PROGS += test_cpu TEST_GEN_PROGS += test_cpuset TEST_GEN_PROGS += test_zswap +TEST_GEN_PROGS += test_hugetlb_memcg LOCAL_HDRS += $(selfdir)/clone3/clone3_selftests.h $(selfdir)/pidfd/pidfd.h @@ -27,3 +28,4 @@ $(OUTPUT)/test_kill: cgroup_util.c $(OUTPUT)/test_cpu: cgroup_util.c $(OUTPUT)/test_cpuset: cgroup_util.c $(OUTPUT)/test_zswap: cgroup_util.c +$(OUTPUT)/test_hugetlb_memcg: cgroup_util.c diff --git a/tools/testing/selftests/cgroup/test_hugetlb_memcg.c b/tools/testing/selftests/cgroup/test_hugetlb_memcg.c new file mode 100644 index 000000000000..9651f6af6914 --- /dev/null +++ b/tools/testing/selftests/cgroup/test_hugetlb_memcg.c @@ -0,0 +1,222 @@ +// SPDX-License-Identifier: GPL-2.0 +#define _GNU_SOURCE + +#include <linux/limits.h> +#include <sys/mman.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <fcntl.h> +#include "../kselftest.h" +#include "cgroup_util.h" + +#define ADDR ((void *)(0x0UL)) +#define FLAGS (MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB) +/* mapping 8 MBs == 4 hugepages */ +#define LENGTH (8UL*1024*1024) +#define PROTECTION (PROT_READ | PROT_WRITE) + +/* borrowed from mm/hmm-tests.c */ +static long get_hugepage_size(void) +{ + int fd; + char buf[2048]; + int len; + char *p, *q, *path = "/proc/meminfo", *tag = "Hugepagesize:"; + long val; + + fd = open(path, O_RDONLY); + if (fd < 0) { + /* Error opening the file */ + return -1; + } + + len = read(fd, buf, sizeof(buf)); + close(fd); + if (len < 0) { + /* Error in reading the file */ + return -1; + } + if (len == sizeof(buf)) { + /* Error file is too large */ + return -1; + } + buf[len] = '\0'; + + /* Search for a tag if provided */ + if (tag) { + p = strstr(buf, tag); + if (!p) + return -1; /* looks like the line we want isn't there */ + p += strlen(tag); + } else + p = buf; + + val = strtol(p, &q, 0); + if (*q != ' ') { + /* Error parsing the file */ + return -1; + } + + return val; +} + +static int set_file(const char *path, long value) +{ + FILE *file; + int ret; + + file = fopen(path, "w"); + if (!file) + return -1; + ret = fprintf(file, "%ld\n", value); + fclose(file); + return ret; +} + +static int set_nr_hugepages(long value) +{ + return set_file("/proc/sys/vm/nr_hugepages", value); +} + +static unsigned int check_first(char *addr) +{ + return *(unsigned int *)addr; +} + +static void write_data(char *addr) +{ + unsigned long i; + + for (i = 0; i < LENGTH; i++) + *(addr + i) = (char)i; +} + +static int hugetlb_test_program(const char *cgroup, void *arg) +{ + char *test_group = (char *)arg; + void *addr; + long old_current, expected_current, current; + int ret = EXIT_FAILURE; + + old_current = cg_read_long(test_group, "memory.current"); + + addr = mmap(ADDR, LENGTH, PROTECTION, FLAGS, 0, 0); + if (addr == MAP_FAILED) { + ksft_print_msg("fail to mmap.\n"); + return EXIT_FAILURE; + } + current = cg_read_long(test_group, "memory.current"); + if (current - old_current >= MB(2)) { + ksft_print_msg("mmap should not increase hugepage usage.\n"); + goto out_failed_munmap; + } + old_current = current; + + /* read the first page */ + check_first(addr); + expected_current = old_current + MB(2); + current = cg_read_long(test_group, "memory.current"); + if (!values_close(expected_current, current, 1)) { + ksft_print_msg("memory usage should increase by around 2MB.\n"); + goto out_failed_munmap; + } + + /* write to the whole range */ + write_data(addr); + current = cg_read_long(test_group, "memory.current"); + expected_current = old_current + MB(8); + if (!values_close(expected_current, current, 1)) { + ksft_print_msg("memory usage should increase by around 8MB.\n"); + goto out_failed_munmap; + } + + /* unmap the whole range */ + munmap(addr, LENGTH); + current = cg_read_long(test_group, "memory.current"); + expected_current = old_current; + if (!values_close(expected_current, current, 1)) { + ksft_print_msg("memory usage should go back down.\n"); + return ret; + } + + ret = EXIT_SUCCESS; + return ret; + +out_failed_munmap: + munmap(addr, LENGTH); + return ret; +} + +static int test_hugetlb_memcg(char *root) +{ + int ret = KSFT_FAIL; + char *test_group; + long old_current, expected_current, current; + + test_group = cg_name(root, "hugetlb_memcg_test"); + + if (!test_group || cg_create(test_group)) { + ksft_print_msg("fail to create cgroup.\n"); + goto out; + } + + if (cg_write(test_group, "memory.max", "100M")) { + ksft_print_msg("fail to set cgroup memory limit.\n"); + goto out; + } + + /* disable swap */ + if (cg_write(test_group, "memory.swap.max", "0")) { + ksft_print_msg("fail to disable swap.\n"); + goto out; + } + old_current = cg_read_long(test_group, "memory.current"); + + set_nr_hugepages(20); + current = cg_read_long(test_group, "memory.current"); + expected_current = old_current; + if (!values_close(expected_current, current, 10)) { + ksft_print_msg( + "memory usage should not increase after setting nr_hugepages.\n"); + goto out; + } + + if (!cg_run(test_group, hugetlb_test_program, (void *)test_group)) + ret = KSFT_PASS; +out: + cg_destroy(test_group); + free(test_group); + return ret; +} + +int main(int argc, char **argv) +{ + char root[PATH_MAX]; + int ret = EXIT_SUCCESS; + + /* Unit is kB! */ + if (get_hugepage_size() != 2048) { + ksft_print_msg("test_hugetlb_memcg requires 2MB hugepages\n"); + ksft_test_result_skip("test_hugetlb_memcg\n"); + return ret; + } + + if (cg_find_unified_root(root, sizeof(root))) + ksft_exit_skip("cgroup v2 isn't mounted\n"); + + switch (test_hugetlb_memcg(root)) { + case KSFT_PASS: + ksft_test_result_pass("test_hugetlb_memcg\n"); + break; + case KSFT_SKIP: + ksft_test_result_skip("test_hugetlb_memcg\n"); + break; + default: + ret = EXIT_FAILURE; + ksft_test_result_fail("test_hugetlb_memcg\n"); + break; + } + + return ret; +} -- 2.34.1