diff options
Diffstat (limited to 'tools/testing/selftests/mm/thp_settings.c')
-rw-r--r-- | tools/testing/selftests/mm/thp_settings.c | 349 |
1 files changed, 349 insertions, 0 deletions
diff --git a/tools/testing/selftests/mm/thp_settings.c b/tools/testing/selftests/mm/thp_settings.c new file mode 100644 index 000000000000..a4163438108e --- /dev/null +++ b/tools/testing/selftests/mm/thp_settings.c @@ -0,0 +1,349 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <fcntl.h> +#include <limits.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include "thp_settings.h" + +#define THP_SYSFS "/sys/kernel/mm/transparent_hugepage/" +#define MAX_SETTINGS_DEPTH 4 +static struct thp_settings settings_stack[MAX_SETTINGS_DEPTH]; +static int settings_index; +static struct thp_settings saved_settings; +static char dev_queue_read_ahead_path[PATH_MAX]; + +static const char * const thp_enabled_strings[] = { + "never", + "always", + "inherit", + "madvise", + NULL +}; + +static const char * const thp_defrag_strings[] = { + "always", + "defer", + "defer+madvise", + "madvise", + "never", + NULL +}; + +static const char * const shmem_enabled_strings[] = { + "always", + "within_size", + "advise", + "never", + "deny", + "force", + NULL +}; + +int read_file(const char *path, char *buf, size_t buflen) +{ + int fd; + ssize_t numread; + + fd = open(path, O_RDONLY); + if (fd == -1) + return 0; + + numread = read(fd, buf, buflen - 1); + if (numread < 1) { + close(fd); + return 0; + } + + buf[numread] = '\0'; + close(fd); + + return (unsigned int) numread; +} + +int write_file(const char *path, const char *buf, size_t buflen) +{ + int fd; + ssize_t numwritten; + + fd = open(path, O_WRONLY); + if (fd == -1) { + printf("open(%s)\n", path); + exit(EXIT_FAILURE); + return 0; + } + + numwritten = write(fd, buf, buflen - 1); + close(fd); + if (numwritten < 1) { + printf("write(%s)\n", buf); + exit(EXIT_FAILURE); + return 0; + } + + return (unsigned int) numwritten; +} + +const unsigned long read_num(const char *path) +{ + char buf[21]; + + if (read_file(path, buf, sizeof(buf)) < 0) { + perror("read_file()"); + exit(EXIT_FAILURE); + } + + return strtoul(buf, NULL, 10); +} + +void write_num(const char *path, unsigned long num) +{ + char buf[21]; + + sprintf(buf, "%ld", num); + if (!write_file(path, buf, strlen(buf) + 1)) { + perror(path); + exit(EXIT_FAILURE); + } +} + +int thp_read_string(const char *name, const char * const strings[]) +{ + char path[PATH_MAX]; + char buf[256]; + char *c; + int ret; + + ret = snprintf(path, PATH_MAX, THP_SYSFS "%s", name); + if (ret >= PATH_MAX) { + printf("%s: Pathname is too long\n", __func__); + exit(EXIT_FAILURE); + } + + if (!read_file(path, buf, sizeof(buf))) { + perror(path); + exit(EXIT_FAILURE); + } + + c = strchr(buf, '['); + if (!c) { + printf("%s: Parse failure\n", __func__); + exit(EXIT_FAILURE); + } + + c++; + memmove(buf, c, sizeof(buf) - (c - buf)); + + c = strchr(buf, ']'); + if (!c) { + printf("%s: Parse failure\n", __func__); + exit(EXIT_FAILURE); + } + *c = '\0'; + + ret = 0; + while (strings[ret]) { + if (!strcmp(strings[ret], buf)) + return ret; + ret++; + } + + printf("Failed to parse %s\n", name); + exit(EXIT_FAILURE); +} + +void thp_write_string(const char *name, const char *val) +{ + char path[PATH_MAX]; + int ret; + + ret = snprintf(path, PATH_MAX, THP_SYSFS "%s", name); + if (ret >= PATH_MAX) { + printf("%s: Pathname is too long\n", __func__); + exit(EXIT_FAILURE); + } + + if (!write_file(path, val, strlen(val) + 1)) { + perror(path); + exit(EXIT_FAILURE); + } +} + +const unsigned long thp_read_num(const char *name) +{ + char path[PATH_MAX]; + int ret; + + ret = snprintf(path, PATH_MAX, THP_SYSFS "%s", name); + if (ret >= PATH_MAX) { + printf("%s: Pathname is too long\n", __func__); + exit(EXIT_FAILURE); + } + return read_num(path); +} + +void thp_write_num(const char *name, unsigned long num) +{ + char path[PATH_MAX]; + int ret; + + ret = snprintf(path, PATH_MAX, THP_SYSFS "%s", name); + if (ret >= PATH_MAX) { + printf("%s: Pathname is too long\n", __func__); + exit(EXIT_FAILURE); + } + write_num(path, num); +} + +void thp_read_settings(struct thp_settings *settings) +{ + unsigned long orders = thp_supported_orders(); + char path[PATH_MAX]; + int i; + + *settings = (struct thp_settings) { + .thp_enabled = thp_read_string("enabled", thp_enabled_strings), + .thp_defrag = thp_read_string("defrag", thp_defrag_strings), + .shmem_enabled = + thp_read_string("shmem_enabled", shmem_enabled_strings), + .use_zero_page = thp_read_num("use_zero_page"), + }; + settings->khugepaged = (struct khugepaged_settings) { + .defrag = thp_read_num("khugepaged/defrag"), + .alloc_sleep_millisecs = + thp_read_num("khugepaged/alloc_sleep_millisecs"), + .scan_sleep_millisecs = + thp_read_num("khugepaged/scan_sleep_millisecs"), + .max_ptes_none = thp_read_num("khugepaged/max_ptes_none"), + .max_ptes_swap = thp_read_num("khugepaged/max_ptes_swap"), + .max_ptes_shared = thp_read_num("khugepaged/max_ptes_shared"), + .pages_to_scan = thp_read_num("khugepaged/pages_to_scan"), + }; + if (dev_queue_read_ahead_path[0]) + settings->read_ahead_kb = read_num(dev_queue_read_ahead_path); + + for (i = 0; i < NR_ORDERS; i++) { + if (!((1 << i) & orders)) { + settings->hugepages[i].enabled = THP_NEVER; + continue; + } + snprintf(path, PATH_MAX, "hugepages-%ukB/enabled", + (getpagesize() >> 10) << i); + settings->hugepages[i].enabled = + thp_read_string(path, thp_enabled_strings); + } +} + +void thp_write_settings(struct thp_settings *settings) +{ + struct khugepaged_settings *khugepaged = &settings->khugepaged; + unsigned long orders = thp_supported_orders(); + char path[PATH_MAX]; + int enabled; + int i; + + thp_write_string("enabled", thp_enabled_strings[settings->thp_enabled]); + thp_write_string("defrag", thp_defrag_strings[settings->thp_defrag]); + thp_write_string("shmem_enabled", + shmem_enabled_strings[settings->shmem_enabled]); + thp_write_num("use_zero_page", settings->use_zero_page); + + thp_write_num("khugepaged/defrag", khugepaged->defrag); + thp_write_num("khugepaged/alloc_sleep_millisecs", + khugepaged->alloc_sleep_millisecs); + thp_write_num("khugepaged/scan_sleep_millisecs", + khugepaged->scan_sleep_millisecs); + thp_write_num("khugepaged/max_ptes_none", khugepaged->max_ptes_none); + thp_write_num("khugepaged/max_ptes_swap", khugepaged->max_ptes_swap); + thp_write_num("khugepaged/max_ptes_shared", khugepaged->max_ptes_shared); + thp_write_num("khugepaged/pages_to_scan", khugepaged->pages_to_scan); + + if (dev_queue_read_ahead_path[0]) + write_num(dev_queue_read_ahead_path, settings->read_ahead_kb); + + for (i = 0; i < NR_ORDERS; i++) { + if (!((1 << i) & orders)) + continue; + snprintf(path, PATH_MAX, "hugepages-%ukB/enabled", + (getpagesize() >> 10) << i); + enabled = settings->hugepages[i].enabled; + thp_write_string(path, thp_enabled_strings[enabled]); + } +} + +struct thp_settings *thp_current_settings(void) +{ + if (!settings_index) { + printf("Fail: No settings set"); + exit(EXIT_FAILURE); + } + return settings_stack + settings_index - 1; +} + +void thp_push_settings(struct thp_settings *settings) +{ + if (settings_index >= MAX_SETTINGS_DEPTH) { + printf("Fail: Settings stack exceeded"); + exit(EXIT_FAILURE); + } + settings_stack[settings_index++] = *settings; + thp_write_settings(thp_current_settings()); +} + +void thp_pop_settings(void) +{ + if (settings_index <= 0) { + printf("Fail: Settings stack empty"); + exit(EXIT_FAILURE); + } + --settings_index; + thp_write_settings(thp_current_settings()); +} + +void thp_restore_settings(void) +{ + thp_write_settings(&saved_settings); +} + +void thp_save_settings(void) +{ + thp_read_settings(&saved_settings); +} + +void thp_set_read_ahead_path(char *path) +{ + if (!path) { + dev_queue_read_ahead_path[0] = '\0'; + return; + } + + strncpy(dev_queue_read_ahead_path, path, + sizeof(dev_queue_read_ahead_path)); + dev_queue_read_ahead_path[sizeof(dev_queue_read_ahead_path) - 1] = '\0'; +} + +unsigned long thp_supported_orders(void) +{ + unsigned long orders = 0; + char path[PATH_MAX]; + char buf[256]; + int ret; + int i; + + for (i = 0; i < NR_ORDERS; i++) { + ret = snprintf(path, PATH_MAX, THP_SYSFS "hugepages-%ukB/enabled", + (getpagesize() >> 10) << i); + if (ret >= PATH_MAX) { + printf("%s: Pathname is too long\n", __func__); + exit(EXIT_FAILURE); + } + + ret = read_file(path, buf, sizeof(buf)); + if (ret) + orders |= 1UL << i; + } + + return orders; +} |