Commit e0c13f97 authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Linus Torvalds

khugepaged: add self test

Patch series "thp/khugepaged improvements and CoW semantics", v4.

The patchset adds khugepaged selftest (anon-THP only for now), expands
cases khugepaged can handle and switches anon-THP copy-on-write handling
to 4k.

This patch (of 8):

The test checks if khugepaged is able to recover huge page where we expect
to do so.  It only covers anon-THP for now.

Currently the test shows few failures.  They are going to be addressed by
the following patches.

[colin.king@canonical.com: fix several spelling mistakes]
  Link: http://lkml.kernel.org/r/20200420084241.65433-1-colin.king@canonical.com
[aneesh.kumar@linux.ibm.com: replace the usage of system(3) in the test]
  Link: http://lkml.kernel.org/r/20200429110727.89388-1-aneesh.kumar@linux.ibm.com
[kirill@shutemov.name: fixup for issues I've noticed]
  Link: http://lkml.kernel.org/r/20200429124816.jp272trghrzxx5j5@box
[jhubbard@nvidia.com: add khugepaged to .gitignore]
  Link: http://lkml.kernel.org/r/20200517002509.362401-1-jhubbard@nvidia.comSigned-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: default avatarColin Ian King <colin.king@canonical.com>
Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: default avatarJohn Hubbard <jhubbard@nvidia.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Tested-by: default avatarZi Yan <ziy@nvidia.com>
Reviewed-by: default avatarWilliam Kucharski <william.kucharski@oracle.com>
Reviewed-by: default avatarZi Yan <ziy@nvidia.com>
Acked-by: default avatarYang Shi <yang.shi@linux.alibaba.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Link: http://lkml.kernel.org/r/20200416160026.16538-1-kirill.shutemov@linux.intel.com
Link: http://lkml.kernel.org/r/20200416160026.16538-2-kirill.shutemov@linux.intel.comSigned-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 633bf2fe
# SPDX-License-Identifier: GPL-2.0-only
hugepage-mmap
hugepage-shm
khugepaged
map_hugetlb
map_populate
thuge-gen
......
......@@ -20,6 +20,7 @@ TEST_GEN_FILES += on-fault-limit
TEST_GEN_FILES += thuge-gen
TEST_GEN_FILES += transhuge-stress
TEST_GEN_FILES += userfaultfd
TEST_GEN_FILES += khugepaged
ifneq (,$(filter $(MACHINE),arm64 ia64 mips64 parisc64 ppc64 ppc64le riscv64 s390x sh64 sparc64 x86_64))
TEST_GEN_FILES += va_128TBswitch
......
#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 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/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"),
.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;
}
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);
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");
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.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();
restore_settings(0);
}
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