diff options
Diffstat (limited to 'tools/testing/selftests/vm/khugepaged.c')
| -rw-r--r-- | tools/testing/selftests/vm/khugepaged.c | 1035 |
1 files changed, 1035 insertions, 0 deletions
diff --git a/tools/testing/selftests/vm/khugepaged.c b/tools/testing/selftests/vm/khugepaged.c new file mode 100644 index 000000000..8b7582130 --- /dev/null +++ b/tools/testing/selftests/vm/khugepaged.c @@ -0,0 +1,1035 @@ +#define _GNU_SOURCE +#include <fcntl.h> +#include <limits.h> +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <stdbool.h> +#include <string.h> +#include <unistd.h> + +#include <sys/mman.h> +#include <sys/wait.h> + +#ifndef MADV_PAGEOUT +#define MADV_PAGEOUT 21 +#endif + +#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" + +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 debug_cow; + bool use_zero_page; + struct khugepaged_settings khugepaged; +}; + +static struct settings default_settings = { + .thp_enabled = THP_MADVISE, + .thp_defrag = THP_DEFRAG_ALWAYS, + .shmem_enabled = SHMEM_NEVER, + .debug_cow = 0, + .use_zero_page = 0, + .khugepaged = { + .defrag = 1, + .alloc_sleep_millisecs = 10, + .scan_sleep_millisecs = 10, + }, +}; + +static struct settings saved_settings; +static bool skip_settings_restore; + +static int exit_status; + +static void success(const char *msg) +{ + printf(" \e[32m%s\e[0m\n", msg); +} + +static void fail(const char *msg) +{ + printf(" \e[31m%s\e[0m\n", msg); + exit_status++; +} + +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) + return 0; + + numwritten = write(fd, buf, buflen - 1); + close(fd); + if (numwritten < 1) + 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 *name) +{ + char path[PATH_MAX]; + char buf[21]; + 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); + } + + ret = read_file(path, buf, sizeof(buf)); + if (ret < 0) { + perror("read_file(read_num)"); + exit(EXIT_FAILURE); + } + + return strtoul(buf, NULL, 10); +} + +static void write_num(const char *name, unsigned long num) +{ + char path[PATH_MAX]; + char buf[21]; + 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); + } + + sprintf(buf, "%ld", num); + if (!write_file(path, buf, strlen(buf) + 1)) { + perror(path); + exit(EXIT_FAILURE); + } +} + +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("debug_cow", settings->debug_cow); + 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); +} + +static void restore_settings(int sig) +{ + if (skip_settings_restore) + goto out; + + printf("Restore THP and khugepaged settings..."); + write_settings(&saved_settings); + success("OK"); + if (sig) + exit(EXIT_FAILURE); +out: + exit(exit_status); +} + +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), + .debug_cow = read_num("debug_cow"), + .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"), + }; + success("OK"); + + signal(SIGTERM, restore_settings); + signal(SIGINT, restore_settings); + signal(SIGHUP, restore_settings); + signal(SIGQUIT, restore_settings); +} + +static void adjust_settings(void) +{ + + printf("Adjust settings..."); + write_settings(&default_settings); + success("OK"); +} + +#define MAX_LINE_LENGTH 500 + +static bool check_for_pattern(FILE *fp, char *pattern, char *buf) +{ + while (fgets(buf, MAX_LINE_LENGTH, fp) != NULL) { + if (!strncmp(buf, pattern, strlen(pattern))) + return true; + } + return false; +} + +static bool check_huge(void *addr) +{ + bool thp = false; + int ret; + FILE *fp; + char buffer[MAX_LINE_LENGTH]; + char addr_pattern[MAX_LINE_LENGTH]; + + ret = snprintf(addr_pattern, MAX_LINE_LENGTH, "%08lx-", + (unsigned long) addr); + if (ret >= MAX_LINE_LENGTH) { + printf("%s: Pattern is too long\n", __func__); + exit(EXIT_FAILURE); + } + + + fp = fopen(PID_SMAPS, "r"); + if (!fp) { + printf("%s: Failed to open file %s\n", __func__, PID_SMAPS); + exit(EXIT_FAILURE); + } + if (!check_for_pattern(fp, addr_pattern, buffer)) + goto err_out; + + ret = snprintf(addr_pattern, MAX_LINE_LENGTH, "AnonHugePages:%10ld kB", + hpage_pmd_size >> 10); + if (ret >= MAX_LINE_LENGTH) { + printf("%s: Pattern is too long\n", __func__); + exit(EXIT_FAILURE); + } + /* + * Fetch the AnonHugePages: in the same block and check whether it got + * the expected number of hugeepages next. + */ + if (!check_for_pattern(fp, "AnonHugePages:", buffer)) + goto err_out; + + if (strncmp(buffer, addr_pattern, strlen(addr_pattern))) + goto err_out; + + thp = true; +err_out: + fclose(fp); + return thp; +} + + +static bool check_swap(void *addr, unsigned long size) +{ + bool swap = false; + int ret; + FILE *fp; + char buffer[MAX_LINE_LENGTH]; + char addr_pattern[MAX_LINE_LENGTH]; + + ret = snprintf(addr_pattern, MAX_LINE_LENGTH, "%08lx-", + (unsigned long) addr); + if (ret >= MAX_LINE_LENGTH) { + printf("%s: Pattern is too long\n", __func__); + exit(EXIT_FAILURE); + } + + + fp = fopen(PID_SMAPS, "r"); + if (!fp) { + printf("%s: Failed to open file %s\n", __func__, PID_SMAPS); + exit(EXIT_FAILURE); + } + if (!check_for_pattern(fp, addr_pattern, buffer)) + goto err_out; + + ret = snprintf(addr_pattern, MAX_LINE_LENGTH, "Swap:%19ld kB", + size >> 10); + if (ret >= MAX_LINE_LENGTH) { + printf("%s: Pattern is too long\n", __func__); + exit(EXIT_FAILURE); + } + /* + * Fetch the Swap: in the same block and check whether it got + * the expected number of hugeepages next. + */ + if (!check_for_pattern(fp, "Swap:", buffer)) + goto err_out; + + if (strncmp(buffer, addr_pattern, strlen(addr_pattern))) + goto err_out; + + swap = true; +err_out: + fclose(fp); + return swap; +} + +static void *alloc_mapping(void) +{ + void *p; + + p = mmap(BASE_ADDR, hpage_pmd_size, PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); + if (p != BASE_ADDR) { + printf("Failed to allocate VMA at %p\n", BASE_ADDR); + exit(EXIT_FAILURE); + } + + return p; +} + +static void fill_memory(int *p, unsigned long start, unsigned long end) +{ + int i; + + for (i = start / page_size; i < end / page_size; i++) + p[i * page_size / sizeof(*p)] = i + 0xdead0000; +} + +static void validate_memory(int *p, unsigned long start, unsigned long end) +{ + int i; + + for (i = start / page_size; i < end / page_size; i++) { + if (p[i * page_size / sizeof(*p)] != i + 0xdead0000) { + printf("Page %d is corrupted: %#x\n", + i, p[i * page_size / sizeof(*p)]); + exit(EXIT_FAILURE); + } + } +} + +#define TICK 500000 +static bool wait_for_scan(const char *msg, char *p) +{ + int full_scans; + int timeout = 6; /* 3 seconds */ + + /* Sanity check */ + if (check_huge(p)) { + printf("Unexpected huge page\n"); + exit(EXIT_FAILURE); + } + + madvise(p, hpage_pmd_size, MADV_HUGEPAGE); + + /* Wait until the second full_scan completed */ + full_scans = read_num("khugepaged/full_scans") + 2; + + printf("%s...", msg); + while (timeout--) { + if (check_huge(p)) + break; + if (read_num("khugepaged/full_scans") >= full_scans) + break; + printf("."); + usleep(TICK); + } + + madvise(p, hpage_pmd_size, MADV_NOHUGEPAGE); + + return timeout == -1; +} + +static void alloc_at_fault(void) +{ + struct settings settings = default_settings; + char *p; + + settings.thp_enabled = THP_ALWAYS; + write_settings(&settings); + + p = alloc_mapping(); + *p = 1; + printf("Allocate huge page on fault..."); + if (check_huge(p)) + success("OK"); + else + fail("Fail"); + + write_settings(&default_settings); + + madvise(p, page_size, MADV_DONTNEED); + printf("Split huge PMD on MADV_DONTNEED..."); + if (!check_huge(p)) + success("OK"); + else + fail("Fail"); + munmap(p, hpage_pmd_size); +} + +static void collapse_full(void) +{ + void *p; + + p = alloc_mapping(); + fill_memory(p, 0, hpage_pmd_size); + if (wait_for_scan("Collapse fully populated PTE table", p)) + fail("Timeout"); + else if (check_huge(p)) + success("OK"); + else + fail("Fail"); + validate_memory(p, 0, hpage_pmd_size); + munmap(p, hpage_pmd_size); +} + +static void collapse_empty(void) +{ + void *p; + + p = alloc_mapping(); + if (wait_for_scan("Do not collapse empty PTE table", p)) + fail("Timeout"); + else if (check_huge(p)) + fail("Fail"); + else + success("OK"); + munmap(p, hpage_pmd_size); +} + +static void collapse_single_pte_entry(void) +{ + void *p; + + p = alloc_mapping(); + fill_memory(p, 0, page_size); + if (wait_for_scan("Collapse PTE table with single PTE entry present", p)) + fail("Timeout"); + else if (check_huge(p)) + success("OK"); + else + fail("Fail"); + validate_memory(p, 0, page_size); + munmap(p, hpage_pmd_size); +} + +static void collapse_max_ptes_none(void) +{ + int max_ptes_none = hpage_pmd_nr / 2; + struct settings settings = default_settings; + void *p; + + settings.khugepaged.max_ptes_none = max_ptes_none; + write_settings(&settings); + + p = alloc_mapping(); + + fill_memory(p, 0, (hpage_pmd_nr - max_ptes_none - 1) * page_size); + if (wait_for_scan("Do not collapse with max_ptes_none exceeded", p)) + fail("Timeout"); + else if (check_huge(p)) + fail("Fail"); + else + success("OK"); + validate_memory(p, 0, (hpage_pmd_nr - max_ptes_none - 1) * page_size); + + fill_memory(p, 0, (hpage_pmd_nr - max_ptes_none) * page_size); + if (wait_for_scan("Collapse with max_ptes_none PTEs empty", p)) + fail("Timeout"); + else if (check_huge(p)) + success("OK"); + else + fail("Fail"); + validate_memory(p, 0, (hpage_pmd_nr - max_ptes_none) * page_size); + + munmap(p, hpage_pmd_size); + write_settings(&default_settings); +} + +static void collapse_swapin_single_pte(void) +{ + void *p; + p = alloc_mapping(); + fill_memory(p, 0, hpage_pmd_size); + + printf("Swapout one page..."); + if (madvise(p, page_size, MADV_PAGEOUT)) { + perror("madvise(MADV_PAGEOUT)"); + exit(EXIT_FAILURE); + } + if (check_swap(p, page_size)) { + success("OK"); + } else { + fail("Fail"); + goto out; + } + + if (wait_for_scan("Collapse with swapping in single PTE entry", p)) + fail("Timeout"); + else if (check_huge(p)) + success("OK"); + else + fail("Fail"); + validate_memory(p, 0, hpage_pmd_size); +out: + munmap(p, hpage_pmd_size); +} + +static void collapse_max_ptes_swap(void) +{ + int max_ptes_swap = read_num("khugepaged/max_ptes_swap"); + void *p; + + p = alloc_mapping(); + + fill_memory(p, 0, hpage_pmd_size); + printf("Swapout %d of %d pages...", max_ptes_swap + 1, hpage_pmd_nr); + if (madvise(p, (max_ptes_swap + 1) * page_size, MADV_PAGEOUT)) { + perror("madvise(MADV_PAGEOUT)"); + exit(EXIT_FAILURE); + } + if (check_swap(p, (max_ptes_swap + 1) * page_size)) { + success("OK"); + } else { + fail("Fail"); + goto out; + } + + if (wait_for_scan("Do not collapse with max_ptes_swap exceeded", p)) + fail("Timeout"); + else if (check_huge(p)) + fail("Fail"); + else + success("OK"); + validate_memory(p, 0, hpage_pmd_size); + + fill_memory(p, 0, hpage_pmd_size); + printf("Swapout %d of %d pages...", max_ptes_swap, hpage_pmd_nr); + if (madvise(p, max_ptes_swap * page_size, MADV_PAGEOUT)) { + perror("madvise(MADV_PAGEOUT)"); + exit(EXIT_FAILURE); + } + if (check_swap(p, max_ptes_swap * page_size)) { + success("OK"); + } else { + fail("Fail"); + goto out; + } + + if (wait_for_scan("Collapse with max_ptes_swap pages swapped out", p)) + fail("Timeout"); + else if (check_huge(p)) + success("OK"); + else + fail("Fail"); + validate_memory(p, 0, hpage_pmd_size); +out: + munmap(p, hpage_pmd_size); +} + +static void collapse_single_pte_entry_compound(void) +{ + void *p; + + p = alloc_mapping(); + + printf("Allocate huge page..."); + madvise(p, hpage_pmd_size, MADV_HUGEPAGE); + fill_memory(p, 0, hpage_pmd_size); + if (check_huge(p)) + success("OK"); + else + fail("Fail"); + madvise(p, hpage_pmd_size, MADV_NOHUGEPAGE); + + printf("Split huge page leaving single PTE mapping compound page..."); + madvise(p + page_size, hpage_pmd_size - page_size, MADV_DONTNEED); + if (!check_huge(p)) + success("OK"); + else + fail("Fail"); + + if (wait_for_scan("Collapse PTE table with single PTE mapping compound page", p)) + fail("Timeout"); + else if (check_huge(p)) + success("OK"); + else + fail("Fail"); + validate_memory(p, 0, page_size); + munmap(p, hpage_pmd_size); +} + +static void collapse_full_of_compound(void) +{ + void *p; + + p = alloc_mapping(); + + printf("Allocate huge page..."); + madvise(p, hpage_pmd_size, MADV_HUGEPAGE); + fill_memory(p, 0, hpage_pmd_size); + if (check_huge(p)) + success("OK"); + else + fail("Fail"); + + printf("Split huge page leaving single PTE page table full of compound pages..."); + madvise(p, page_size, MADV_NOHUGEPAGE); + madvise(p, hpage_pmd_size, MADV_NOHUGEPAGE); + if (!check_huge(p)) + success("OK"); + else + fail("Fail"); + + if (wait_for_scan("Collapse PTE table full of compound pages", p)) + fail("Timeout"); + else if (check_huge(p)) + success("OK"); + else + fail("Fail"); + validate_memory(p, 0, hpage_pmd_size); + munmap(p, hpage_pmd_size); +} + +static void collapse_compound_extreme(void) +{ + void *p; + int i; + + p = alloc_mapping(); + for (i = 0; i < hpage_pmd_nr; i++) { + printf("\rConstruct PTE page table full of different PTE-mapped compound pages %3d/%d...", + i + 1, hpage_pmd_nr); + + madvise(BASE_ADDR, hpage_pmd_size, MADV_HUGEPAGE); + fill_memory(BASE_ADDR, 0, hpage_pmd_size); + if (!check_huge(BASE_ADDR)) { + printf("Failed to allocate huge page\n"); + exit(EXIT_FAILURE); + } + madvise(BASE_ADDR, hpage_pmd_size, MADV_NOHUGEPAGE); + + p = mremap(BASE_ADDR - i * page_size, + i * page_size + hpage_pmd_size, + (i + 1) * page_size, + MREMAP_MAYMOVE | MREMAP_FIXED, + BASE_ADDR + 2 * hpage_pmd_size); + if (p == MAP_FAILED) { + perror("mremap+unmap"); + exit(EXIT_FAILURE); + } + + p = mremap(BASE_ADDR + 2 * hpage_pmd_size, + (i + 1) * page_size, + (i + 1) * page_size + hpage_pmd_size, + MREMAP_MAYMOVE | MREMAP_FIXED, + BASE_ADDR - (i + 1) * page_size); + if (p == MAP_FAILED) { + perror("mremap+alloc"); + exit(EXIT_FAILURE); + } + } + + munmap(BASE_ADDR, hpage_pmd_size); + fill_memory(p, 0, hpage_pmd_size); + if (!check_huge(p)) + success("OK"); + else + fail("Fail"); + + if (wait_for_scan("Collapse PTE table full of different compound pages", p)) + fail("Timeout"); + else if (check_huge(p)) + success("OK"); + else + fail("Fail"); + + validate_memory(p, 0, hpage_pmd_size); + munmap(p, hpage_pmd_size); +} + +static void collapse_fork(void) +{ + int wstatus; + void *p; + + p = alloc_mapping(); + + printf("Allocate small page..."); + fill_memory(p, 0, page_size); + if (!check_huge(p)) + success("OK"); + else + fail("Fail"); + + printf("Share small page over fork()..."); + if (!fork()) { + /* Do not touch settings on child exit */ + skip_settings_restore = true; + exit_status = 0; + + if (!check_huge(p)) + success("OK"); + else + fail("Fail"); + + fill_memory(p, page_size, 2 * page_size); + + if (wait_for_scan("Collapse PTE table with single page shared with parent process", p)) + fail("Timeout"); + else if (check_huge(p)) + success("OK"); + else + fail("Fail"); + + validate_memory(p, 0, page_size); + munmap(p, hpage_pmd_size); + exit(exit_status); + } + + wait(&wstatus); + exit_status += WEXITSTATUS(wstatus); + + printf("Check if parent still has small page..."); + if (!check_huge(p)) + success("OK"); + else + fail("Fail"); + validate_memory(p, 0, page_size); + munmap(p, hpage_pmd_size); +} + +static void collapse_fork_compound(void) +{ + int wstatus; + void *p; + + p = alloc_mapping(); + + printf("Allocate huge page..."); + madvise(p, hpage_pmd_size, MADV_HUGEPAGE); + fill_memory(p, 0, hpage_pmd_size); + if (check_huge(p)) + success("OK"); + else + fail("Fail"); + + printf("Share huge page over fork()..."); + if (!fork()) { + /* Do not touch settings on child exit */ + skip_settings_restore = true; + exit_status = 0; + + if (check_huge(p)) + success("OK"); + else + fail("Fail"); + + printf("Split huge page PMD in child process..."); + madvise(p, page_size, MADV_NOHUGEPAGE); + madvise(p, hpage_pmd_size, MADV_NOHUGEPAGE); + if (!check_huge(p)) + success("OK"); + else + fail("Fail"); + fill_memory(p, 0, page_size); + + write_num("khugepaged/max_ptes_shared", hpage_pmd_nr - 1); + if (wait_for_scan("Collapse PTE table full of compound pages in child", p)) + fail("Timeout"); + else if (check_huge(p)) + success("OK"); + else + fail("Fail"); + write_num("khugepaged/max_ptes_shared", + default_settings.khugepaged.max_ptes_shared); + + validate_memory(p, 0, hpage_pmd_size); + munmap(p, hpage_pmd_size); + exit(exit_status); + } + + wait(&wstatus); + exit_status += WEXITSTATUS(wstatus); + + printf("Check if parent still has huge page..."); + if (check_huge(p)) + success("OK"); + else + fail("Fail"); + validate_memory(p, 0, hpage_pmd_size); + munmap(p, hpage_pmd_size); +} + +static void collapse_max_ptes_shared() +{ + int max_ptes_shared = read_num("khugepaged/max_ptes_shared"); + int wstatus; + void *p; + + p = alloc_mapping(); + + printf("Allocate huge page..."); + madvise(p, hpage_pmd_size, MADV_HUGEPAGE); + fill_memory(p, 0, hpage_pmd_size); + if (check_huge(p)) + success("OK"); + else + fail("Fail"); + + printf("Share huge page over fork()..."); + if (!fork()) { + /* Do not touch settings on child exit */ + skip_settings_restore = true; + exit_status = 0; + + if (check_huge(p)) + success("OK"); + else + fail("Fail"); + + printf("Trigger CoW on page %d of %d...", + hpage_pmd_nr - max_ptes_shared - 1, hpage_pmd_nr); + fill_memory(p, 0, (hpage_pmd_nr - max_ptes_shared - 1) * page_size); + if (!check_huge(p)) + success("OK"); + else + fail("Fail"); + + if (wait_for_scan("Do not collapse with max_ptes_shared exceeded", p)) + fail("Timeout"); + else if (!check_huge(p)) + success("OK"); + else + fail("Fail"); + + printf("Trigger CoW on page %d of %d...", + hpage_pmd_nr - max_ptes_shared, hpage_pmd_nr); + fill_memory(p, 0, (hpage_pmd_nr - max_ptes_shared) * page_size); + if (!check_huge(p)) + success("OK"); + else + fail("Fail"); + + + if (wait_for_scan("Collapse with max_ptes_shared PTEs shared", p)) + fail("Timeout"); + else if (check_huge(p)) + success("OK"); + else + fail("Fail"); + + validate_memory(p, 0, hpage_pmd_size); + munmap(p, hpage_pmd_size); + exit(exit_status); + } + + wait(&wstatus); + exit_status += WEXITSTATUS(wstatus); + + printf("Check if parent still has huge page..."); + if (check_huge(p)) + success("OK"); + else + fail("Fail"); + validate_memory(p, 0, hpage_pmd_size); + munmap(p, hpage_pmd_size); +} + +int main(void) +{ + setbuf(stdout, NULL); + + page_size = getpagesize(); + hpage_pmd_size = read_num("hpage_pmd_size"); + hpage_pmd_nr = hpage_pmd_size / page_size; + + default_settings.khugepaged.max_ptes_none = hpage_pmd_nr - 1; + default_settings.khugepaged.max_ptes_swap = hpage_pmd_nr / 8; + default_settings.khugepaged.max_ptes_shared = hpage_pmd_nr / 2; + default_settings.khugepaged.pages_to_scan = hpage_pmd_nr * 8; + + save_settings(); + adjust_settings(); + + alloc_at_fault(); + collapse_full(); + collapse_empty(); + collapse_single_pte_entry(); + collapse_max_ptes_none(); + collapse_swapin_single_pte(); + collapse_max_ptes_swap(); + collapse_single_pte_entry_compound(); + collapse_full_of_compound(); + collapse_compound_extreme(); + collapse_fork(); + collapse_fork_compound(); + collapse_max_ptes_shared(); + + restore_settings(0); +} |