The patch titled Subject: selftests/mm: factor out thp settings management has been added to the -mm mm-unstable branch. Its filename is selftests-mm-factor-out-thp-settings-management.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-mm-factor-out-thp-settings-management.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Ryan Roberts <ryan.roberts@xxxxxxx> Subject: selftests/mm: factor out thp settings management Date: Thu, 7 Dec 2023 16:12:07 +0000 The khugepaged test has a useful framework for save/restore/pop/push of all thp settings via the sysfs interface. This will be useful to explicitly control multi-size THP settings in other tests, so let's move it out of khugepaged and into its own thp_settings.[c|h] utility. Link: https://lkml.kernel.org/r/20231207161211.2374093-7-ryan.roberts@xxxxxxx Signed-off-by: Ryan Roberts <ryan.roberts@xxxxxxx> Tested-by: Alistair Popple <apopple@xxxxxxxxxx> Acked-by: David Hildenbrand <david@xxxxxxxxxx> Tested-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> Tested-by: John Hubbard <jhubbard@xxxxxxxxxx> Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx> Cc: Barry Song <v-songbaohua@xxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: "Huang, Ying" <ying.huang@xxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Itaru Kitayama <itaru.kitayama@xxxxxxxxx> Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx> Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: Yang Shi <shy828301@xxxxxxxxx> Cc: Yin Fengwei <fengwei.yin@xxxxxxxxx> Cc: Yu Zhao <yuzhao@xxxxxxxxxx> Cc: Zi Yan <ziy@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- tools/testing/selftests/mm/Makefile | 4 tools/testing/selftests/mm/khugepaged.c | 346 +------------------- tools/testing/selftests/mm/thp_settings.c | 296 +++++++++++++++++ tools/testing/selftests/mm/thp_settings.h | 71 ++++ 4 files changed, 391 insertions(+), 326 deletions(-) --- a/tools/testing/selftests/mm/khugepaged.c~selftests-mm-factor-out-thp-settings-management +++ a/tools/testing/selftests/mm/khugepaged.c @@ -22,13 +22,13 @@ #include "linux/magic.h" #include "vm_util.h" +#include "thp_settings.h" #define BASE_ADDR ((void *)(1UL << 30)) static unsigned long hpage_pmd_size; static unsigned long page_size; static int hpage_pmd_nr; -#define THP_SYSFS "/sys/kernel/mm/transparent_hugepage/" #define PID_SMAPS "/proc/self/smaps" #define TEST_FILE "collapse_test_file" @@ -71,78 +71,7 @@ struct file_info { }; static struct file_info finfo; - -enum thp_enabled { - THP_ALWAYS, - THP_MADVISE, - THP_NEVER, -}; - -static const char *thp_enabled_strings[] = { - "always", - "madvise", - "never", - NULL -}; - -enum thp_defrag { - THP_DEFRAG_ALWAYS, - THP_DEFRAG_DEFER, - THP_DEFRAG_DEFER_MADVISE, - THP_DEFRAG_MADVISE, - THP_DEFRAG_NEVER, -}; - -static const char *thp_defrag_strings[] = { - "always", - "defer", - "defer+madvise", - "madvise", - "never", - NULL -}; - -enum shmem_enabled { - SHMEM_ALWAYS, - SHMEM_WITHIN_SIZE, - SHMEM_ADVISE, - SHMEM_NEVER, - SHMEM_DENY, - SHMEM_FORCE, -}; - -static const char *shmem_enabled_strings[] = { - "always", - "within_size", - "advise", - "never", - "deny", - "force", - NULL -}; - -struct khugepaged_settings { - bool defrag; - unsigned int alloc_sleep_millisecs; - unsigned int scan_sleep_millisecs; - unsigned int max_ptes_none; - unsigned int max_ptes_swap; - unsigned int max_ptes_shared; - unsigned long pages_to_scan; -}; - -struct settings { - enum thp_enabled thp_enabled; - enum thp_defrag thp_defrag; - enum shmem_enabled shmem_enabled; - bool use_zero_page; - struct khugepaged_settings khugepaged; - unsigned long read_ahead_kb; -}; - -static struct settings saved_settings; static bool skip_settings_restore; - static int exit_status; static void success(const char *msg) @@ -161,226 +90,13 @@ static void skip(const char *msg) printf(" \e[33m%s\e[0m\n", msg); } -static 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; -} - -static 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; -} - -static int read_string(const char *name, const char *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); -} - -static void 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); - } -} - -static const unsigned long _read_num(const char *path) -{ - char buf[21]; - - if (read_file(path, buf, sizeof(buf)) < 0) { - perror("read_file(read_num)"); - exit(EXIT_FAILURE); - } - - return strtoul(buf, NULL, 10); -} - -static const unsigned long 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); -} - -static 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); - } -} - -static void 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); -} - -static void write_settings(struct settings *settings) -{ - struct khugepaged_settings *khugepaged = &settings->khugepaged; - - write_string("enabled", thp_enabled_strings[settings->thp_enabled]); - write_string("defrag", thp_defrag_strings[settings->thp_defrag]); - write_string("shmem_enabled", - shmem_enabled_strings[settings->shmem_enabled]); - write_num("use_zero_page", settings->use_zero_page); - - write_num("khugepaged/defrag", khugepaged->defrag); - write_num("khugepaged/alloc_sleep_millisecs", - khugepaged->alloc_sleep_millisecs); - write_num("khugepaged/scan_sleep_millisecs", - khugepaged->scan_sleep_millisecs); - write_num("khugepaged/max_ptes_none", khugepaged->max_ptes_none); - write_num("khugepaged/max_ptes_swap", khugepaged->max_ptes_swap); - write_num("khugepaged/max_ptes_shared", khugepaged->max_ptes_shared); - write_num("khugepaged/pages_to_scan", khugepaged->pages_to_scan); - - if (file_ops && finfo.type == VMA_FILE) - _write_num(finfo.dev_queue_read_ahead_path, - settings->read_ahead_kb); -} - -#define MAX_SETTINGS_DEPTH 4 -static struct settings settings_stack[MAX_SETTINGS_DEPTH]; -static int settings_index; - -static struct settings *current_settings(void) -{ - if (!settings_index) { - printf("Fail: No settings set"); - exit(EXIT_FAILURE); - } - return settings_stack + settings_index - 1; -} - -static void push_settings(struct settings *settings) -{ - if (settings_index >= MAX_SETTINGS_DEPTH) { - printf("Fail: Settings stack exceeded"); - exit(EXIT_FAILURE); - } - settings_stack[settings_index++] = *settings; - write_settings(current_settings()); -} - -static void pop_settings(void) -{ - if (settings_index <= 0) { - printf("Fail: Settings stack empty"); - exit(EXIT_FAILURE); - } - --settings_index; - write_settings(current_settings()); -} - static void restore_settings_atexit(void) { if (skip_settings_restore) return; printf("Restore THP and khugepaged settings..."); - write_settings(&saved_settings); + thp_restore_settings(); success("OK"); skip_settings_restore = true; @@ -395,27 +111,9 @@ static void restore_settings(int sig) static void save_settings(void) { printf("Save THP and khugepaged settings..."); - saved_settings = (struct settings) { - .thp_enabled = read_string("enabled", thp_enabled_strings), - .thp_defrag = read_string("defrag", thp_defrag_strings), - .shmem_enabled = - read_string("shmem_enabled", shmem_enabled_strings), - .use_zero_page = read_num("use_zero_page"), - }; - saved_settings.khugepaged = (struct khugepaged_settings) { - .defrag = read_num("khugepaged/defrag"), - .alloc_sleep_millisecs = - read_num("khugepaged/alloc_sleep_millisecs"), - .scan_sleep_millisecs = - read_num("khugepaged/scan_sleep_millisecs"), - .max_ptes_none = read_num("khugepaged/max_ptes_none"), - .max_ptes_swap = read_num("khugepaged/max_ptes_swap"), - .max_ptes_shared = read_num("khugepaged/max_ptes_shared"), - .pages_to_scan = read_num("khugepaged/pages_to_scan"), - }; if (file_ops && finfo.type == VMA_FILE) - saved_settings.read_ahead_kb = - _read_num(finfo.dev_queue_read_ahead_path); + thp_set_read_ahead_path(finfo.dev_queue_read_ahead_path); + thp_save_settings(); success("OK"); @@ -798,7 +496,7 @@ static void __madvise_collapse(const cha struct mem_ops *ops, bool expect) { int ret; - struct settings settings = *current_settings(); + struct thp_settings settings = *thp_current_settings(); printf("%s...", msg); @@ -808,7 +506,7 @@ static void __madvise_collapse(const cha */ settings.thp_enabled = THP_NEVER; settings.shmem_enabled = SHMEM_NEVER; - push_settings(&settings); + thp_push_settings(&settings); /* Clear VM_NOHUGEPAGE */ madvise(p, nr_hpages * hpage_pmd_size, MADV_HUGEPAGE); @@ -820,7 +518,7 @@ static void __madvise_collapse(const cha else success("OK"); - pop_settings(); + thp_pop_settings(); } static void madvise_collapse(const char *msg, char *p, int nr_hpages, @@ -850,13 +548,13 @@ static bool wait_for_scan(const char *ms madvise(p, nr_hpages * hpage_pmd_size, MADV_HUGEPAGE); /* Wait until the second full_scan completed */ - full_scans = read_num("khugepaged/full_scans") + 2; + full_scans = thp_read_num("khugepaged/full_scans") + 2; printf("%s...", msg); while (timeout--) { if (ops->check_huge(p, nr_hpages)) break; - if (read_num("khugepaged/full_scans") >= full_scans) + if (thp_read_num("khugepaged/full_scans") >= full_scans) break; printf("."); usleep(TICK); @@ -911,11 +609,11 @@ static bool is_tmpfs(struct mem_ops *ops static void alloc_at_fault(void) { - struct settings settings = *current_settings(); + struct thp_settings settings = *thp_current_settings(); char *p; settings.thp_enabled = THP_ALWAYS; - push_settings(&settings); + thp_push_settings(&settings); p = alloc_mapping(1); *p = 1; @@ -925,7 +623,7 @@ static void alloc_at_fault(void) else fail("Fail"); - pop_settings(); + thp_pop_settings(); madvise(p, page_size, MADV_DONTNEED); printf("Split huge PMD on MADV_DONTNEED..."); @@ -973,11 +671,11 @@ static void collapse_single_pte_entry(st static void collapse_max_ptes_none(struct collapse_context *c, struct mem_ops *ops) { int max_ptes_none = hpage_pmd_nr / 2; - struct settings settings = *current_settings(); + struct thp_settings settings = *thp_current_settings(); void *p; settings.khugepaged.max_ptes_none = max_ptes_none; - push_settings(&settings); + thp_push_settings(&settings); p = ops->setup_area(1); @@ -1002,7 +700,7 @@ static void collapse_max_ptes_none(struc } skip: ops->cleanup_area(p, hpage_pmd_size); - pop_settings(); + thp_pop_settings(); } static void collapse_swapin_single_pte(struct collapse_context *c, struct mem_ops *ops) @@ -1033,7 +731,7 @@ out: static void collapse_max_ptes_swap(struct collapse_context *c, struct mem_ops *ops) { - int max_ptes_swap = read_num("khugepaged/max_ptes_swap"); + int max_ptes_swap = thp_read_num("khugepaged/max_ptes_swap"); void *p; p = ops->setup_area(1); @@ -1250,11 +948,11 @@ static void collapse_fork_compound(struc fail("Fail"); ops->fault(p, 0, page_size); - write_num("khugepaged/max_ptes_shared", hpage_pmd_nr - 1); + thp_write_num("khugepaged/max_ptes_shared", hpage_pmd_nr - 1); c->collapse("Collapse PTE table full of compound pages in child", p, 1, ops, true); - write_num("khugepaged/max_ptes_shared", - current_settings()->khugepaged.max_ptes_shared); + thp_write_num("khugepaged/max_ptes_shared", + thp_current_settings()->khugepaged.max_ptes_shared); validate_memory(p, 0, hpage_pmd_size); ops->cleanup_area(p, hpage_pmd_size); @@ -1275,7 +973,7 @@ static void collapse_fork_compound(struc static void collapse_max_ptes_shared(struct collapse_context *c, struct mem_ops *ops) { - int max_ptes_shared = read_num("khugepaged/max_ptes_shared"); + int max_ptes_shared = thp_read_num("khugepaged/max_ptes_shared"); int wstatus; void *p; @@ -1443,7 +1141,7 @@ static void parse_test_type(int argc, co int main(int argc, const char **argv) { - struct settings default_settings = { + struct thp_settings default_settings = { .thp_enabled = THP_MADVISE, .thp_defrag = THP_DEFRAG_ALWAYS, .shmem_enabled = SHMEM_ADVISE, @@ -1484,7 +1182,7 @@ int main(int argc, const char **argv) default_settings.khugepaged.pages_to_scan = hpage_pmd_nr * 8; save_settings(); - push_settings(&default_settings); + thp_push_settings(&default_settings); alloc_at_fault(); --- a/tools/testing/selftests/mm/Makefile~selftests-mm-factor-out-thp-settings-management +++ a/tools/testing/selftests/mm/Makefile @@ -117,8 +117,8 @@ TEST_FILES += va_high_addr_switch.sh include ../lib.mk -$(TEST_GEN_PROGS): vm_util.c -$(TEST_GEN_FILES): vm_util.c +$(TEST_GEN_PROGS): vm_util.c thp_settings.c +$(TEST_GEN_FILES): vm_util.c thp_settings.c $(OUTPUT)/uffd-stress: uffd-common.c $(OUTPUT)/uffd-unit-tests: uffd-common.c --- /dev/null +++ a/tools/testing/selftests/mm/thp_settings.c @@ -0,0 +1,296 @@ +// 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[] = { + "always", + "madvise", + "never", + 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) +{ + *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); +} + +void thp_write_settings(struct thp_settings *settings) +{ + struct khugepaged_settings *khugepaged = &settings->khugepaged; + + 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); +} + +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'; +} --- /dev/null +++ a/tools/testing/selftests/mm/thp_settings.h @@ -0,0 +1,71 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __THP_SETTINGS_H__ +#define __THP_SETTINGS_H__ + +#include <stdbool.h> +#include <stddef.h> +#include <stdint.h> + +enum thp_enabled { + THP_ALWAYS, + THP_MADVISE, + THP_NEVER, +}; + +enum thp_defrag { + THP_DEFRAG_ALWAYS, + THP_DEFRAG_DEFER, + THP_DEFRAG_DEFER_MADVISE, + THP_DEFRAG_MADVISE, + THP_DEFRAG_NEVER, +}; + +enum shmem_enabled { + SHMEM_ALWAYS, + SHMEM_WITHIN_SIZE, + SHMEM_ADVISE, + SHMEM_NEVER, + SHMEM_DENY, + SHMEM_FORCE, +}; + +struct khugepaged_settings { + bool defrag; + unsigned int alloc_sleep_millisecs; + unsigned int scan_sleep_millisecs; + unsigned int max_ptes_none; + unsigned int max_ptes_swap; + unsigned int max_ptes_shared; + unsigned long pages_to_scan; +}; + +struct thp_settings { + enum thp_enabled thp_enabled; + enum thp_defrag thp_defrag; + enum shmem_enabled shmem_enabled; + bool use_zero_page; + struct khugepaged_settings khugepaged; + unsigned long read_ahead_kb; +}; + +int read_file(const char *path, char *buf, size_t buflen); +int write_file(const char *path, const char *buf, size_t buflen); +const unsigned long read_num(const char *path); +void write_num(const char *path, unsigned long num); + +int thp_read_string(const char *name, const char * const strings[]); +void thp_write_string(const char *name, const char *val); +const unsigned long thp_read_num(const char *name); +void thp_write_num(const char *name, unsigned long num); + +void thp_write_settings(struct thp_settings *settings); +void thp_read_settings(struct thp_settings *settings); +struct thp_settings *thp_current_settings(void); +void thp_push_settings(struct thp_settings *settings); +void thp_pop_settings(void); +void thp_restore_settings(void); +void thp_save_settings(void); + +void thp_set_read_ahead_path(char *path); + +#endif /* __THP_SETTINGS_H__ */ _ Patches currently in -mm which might be from ryan.roberts@xxxxxxx are mm-readahead-do-not-allow-order-1-folio.patch mm-allow-deferred-splitting-of-arbitrary-anon-large-folios.patch mm-non-pmd-mappable-large-folios-for-folio_add_new_anon_rmap.patch mm-thp-introduce-multi-size-thp-sysfs-interface.patch mm-thp-support-allocation-of-anonymous-multi-size-thp.patch selftests-mm-kugepaged-restore-thp-settings-at-exit.patch selftests-mm-factor-out-thp-settings-management.patch selftests-mm-support-multi-size-thp-interface-in-thp_settings.patch selftests-mm-khugepaged-enlighten-for-multi-size-thp.patch selftests-mm-cow-generalize-do_run_with_thp-helper.patch selftests-mm-cow-add-tests-for-anonymous-multi-size-thp.patch