// 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");
set_nr_hugepages(20);
current = cg_read_long(test_group, "memory.current");
if (current - old_current >= MB(2)) {
ksft_print_msg(
"setting nr_hugepages should not increase hugepage usage.\n");
ksft_print_msg("before: %ld, after: %ld\n", old_current, current);
return EXIT_FAILURE;
}
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");
ksft_print_msg("before: %ld, after: %ld\n", old_current, current);
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, 5)) {
ksft_print_msg("memory usage should increase by around 2MB.\n");
ksft_print_msg(
"expected memory: %ld, actual memory: %ld\n",
expected_current, current);
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, 5)) {
ksft_print_msg("memory usage should increase by around 8MB.\n");
ksft_print_msg(
"expected memory: %ld, actual memory: %ld\n",
expected_current, current);
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, 5)) {
ksft_print_msg("memory usage should go back down.\n");
ksft_print_msg(
"expected memory: %ld, actual memory: %ld\n",
expected_current, current);
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;
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;
}
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, has_memory_hugetlb_acc;
has_memory_hugetlb_acc = proc_mount_contains("memory_hugetlb_accounting");
if (has_memory_hugetlb_acc < 0)
ksft_exit_skip("Failed to query cgroup mount option\n");
else if (!has_memory_hugetlb_acc)
ksft_exit_skip("memory hugetlb accounting is disabled\n");
/* 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), NULL))
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;
}
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