[PATCH 7.2 v3 11/12] selftests/mm: remove READ_ONLY_THP_FOR_FS in khugepaged

Zi Yan
2026-04-18T02:45:10Z

Change the requirement to a file system with large folio support and the
supported order needs to include PMD_ORDER.

Also add tests of opening a file with read write permission and populating
folios with writes. Reuse the XFS image from split_huge_page_test.

Signed-off-by: Zi Yan <ziy@nvidia.com>
---
tools/testing/selftests/mm/khugepaged.c | 110 ++++++++++++++++------
tools/testing/selftests/mm/run_vmtests.sh | 12 ++-
2 files changed, 90 insertions(+), 32 deletions(-)

diff --git a/tools/testing/selftests/mm/khugepaged.c b/tools/testing/selftests/mm/khugepaged.c
index 3fe7ef04ac62..627472cbc910 100644
--- a/tools/testing/selftests/mm/khugepaged.c
+++ b/tools/testing/selftests/mm/khugepaged.c
@@ -49,7 +49,8 @@ struct mem_ops {
const char *name;
};

-static struct mem_ops *file_ops;
+static struct mem_ops *read_only_file_ops;
+static struct mem_ops *read_write_file_ops;
static struct mem_ops *anon_ops;
static struct mem_ops *shmem_ops;

@@ -112,7 +113,8 @@ static void restore_settings(int sig)
static void save_settings(void)
{
printf("Save THP and khugepaged settings...");
- if (file_ops && finfo.type == VMA_FILE)
+ if ((read_only_file_ops || read_write_file_ops) &&
+ finfo.type == VMA_FILE)
thp_set_read_ahead_path(finfo.dev_queue_read_ahead_path);
thp_save_settings();

@@ -364,11 +366,14 @@ static bool anon_check_huge(void *addr, int nr_hpages)
return check_huge_anon(addr, nr_hpages, hpage_pmd_size);
}

-static void *file_setup_area(int nr_hpages)
+static void *file_setup_area_common(int nr_hpages, bool read_only)
{
int fd;
void *p;
unsigned long size;
+ int open_opt = read_only ? O_RDONLY : O_RDWR;
+ int mmap_prot = read_only ? PROT_READ : (PROT_READ | PROT_WRITE);
+ int mmap_opt = read_only ? MAP_PRIVATE : MAP_SHARED;

unlink(finfo.path); /* Cleanup from previous failed tests */
printf("Creating %s for collapse%s...", finfo.path,
@@ -388,14 +393,15 @@ static void *file_setup_area(int nr_hpages)
munmap(p, size);
success("OK");

- printf("Opening %s read only for collapse...", finfo.path);
- finfo.fd = open(finfo.path, O_RDONLY, 777);
+ printf("Opening %s %s for collapse...", finfo.path,
+ read_only ? "read only" : "read-write");
+ finfo.fd = open(finfo.path, open_opt, 777);
if (finfo.fd < 0) {
perror("open()");
exit(EXIT_FAILURE);
}
- p = mmap(BASE_ADDR, size, PROT_READ,
- MAP_PRIVATE, finfo.fd, 0);
+ p = mmap(BASE_ADDR, size, mmap_prot,
+ mmap_opt, finfo.fd, 0);
if (p == MAP_FAILED || p != BASE_ADDR) {
perror("mmap()");
exit(EXIT_FAILURE);
@@ -407,6 +413,15 @@ static void *file_setup_area(int nr_hpages)
return p;
}

+static void *file_setup_read_only_area(int nr_hpages)
+{
+ return file_setup_area_common(nr_hpages, /* read_only= */ true);
+}
+
+static void *file_setup_read_write_area(int nr_hpages)
+{
+ return file_setup_area_common(nr_hpages, /* read_only= */ false);
+}
static void file_cleanup_area(void *p, unsigned long size)
{
munmap(p, size);
@@ -414,14 +429,25 @@ static void file_cleanup_area(void *p, unsigned long size)
unlink(finfo.path);
}

-static void file_fault(void *p, unsigned long start, unsigned long end)
+static void file_fault_common(void *p, unsigned long start, unsigned long end,
+ int madv_ops)
{
- if (madvise(((char *)p) + start, end - start, MADV_POPULATE_READ)) {
+ if (madvise(((char *)p) + start, end - start, madv_ops)) {
perror("madvise(MADV_POPULATE_READ");
exit(EXIT_FAILURE);
}
}

+static void file_fault_read(void *p, unsigned long start, unsigned long end)
+{
+ file_fault_common(p, start, end, MADV_POPULATE_READ);
+}
+
+static void file_fault_write(void *p, unsigned long start, unsigned long end)
+{
+ file_fault_common(p, start, end, MADV_POPULATE_WRITE);
+}
+
static bool file_check_huge(void *addr, int nr_hpages)
{
switch (finfo.type) {
@@ -477,10 +503,18 @@ static struct mem_ops __anon_ops = {
.name = "anon",
};

-static struct mem_ops __file_ops = {
- .setup_area = &file_setup_area,
+static struct mem_ops __read_only_file_ops = {
+ .setup_area = &file_setup_read_only_area,
+ .cleanup_area = &file_cleanup_area,
+ .fault = &file_fault_read,
+ .check_huge = &file_check_huge,
+ .name = "file",
+};
+
+static struct mem_ops __read_write_file_ops = {
+ .setup_area = &file_setup_read_write_area,
.cleanup_area = &file_cleanup_area,
- .fault = &file_fault,
+ .fault = &file_fault_write,
.check_huge = &file_check_huge,
.name = "file",
};
@@ -603,7 +637,9 @@ static struct collapse_context __madvise_context = {

static bool is_tmpfs(struct mem_ops *ops)
{
- return ops == &__file_ops && finfo.type == VMA_SHMEM;
+ return (ops == &__read_only_file_ops ||
+ ops == &__read_write_file_ops) &&
+ finfo.type == VMA_SHMEM;
}

static bool is_anon(struct mem_ops *ops)
@@ -1086,8 +1122,8 @@ static void usage(void)
fprintf(stderr, "\t<context>\t: [all|khugepaged|madvise]\n");
fprintf(stderr, "\t<mem_type>\t: [all|anon|file|shmem]\n");
fprintf(stderr, "\n\t\"file,all\" mem_type requires [dir] argument\n");
- fprintf(stderr, "\n\t\"file,all\" mem_type requires kernel built with\n");
- fprintf(stderr, "\tCONFIG_READ_ONLY_THP_FOR_FS=y\n");
+ fprintf(stderr, "\n\t\"file,all\" mem_type requires a file system\n");
+ fprintf(stderr, "\twith large folio support (order >= PMD order)\n");
fprintf(stderr, "\n\tif [dir] is a (sub)directory of a tmpfs mount, tmpfs must be\n");
fprintf(stderr, "\tmounted with huge=advise option for khugepaged tests to work\n");
fprintf(stderr, "\n\tSupported Options:\n");
@@ -1143,20 +1179,22 @@ static void parse_test_type(int argc, char **argv)
usage();

if (!strcmp(buf, "all")) {
- file_ops = &__file_ops;
+ read_only_file_ops = &__read_only_file_ops;
+ read_write_file_ops = &__read_write_file_ops;
anon_ops = &__anon_ops;
shmem_ops = &__shmem_ops;
} else if (!strcmp(buf, "anon")) {
anon_ops = &__anon_ops;
} else if (!strcmp(buf, "file")) {
- file_ops = &__file_ops;
+ read_only_file_ops = &__read_only_file_ops;
+ read_write_file_ops = &__read_write_file_ops;
} else if (!strcmp(buf, "shmem")) {
shmem_ops = &__shmem_ops;
} else {
usage();
}

- if (!file_ops)
+ if (!read_only_file_ops && !read_write_file_ops)
return;

if (argc != 2)
@@ -1228,37 +1266,47 @@ int main(int argc, char **argv)
} while (0)

TEST(collapse_full, khugepaged_context, anon_ops);
- TEST(collapse_full, khugepaged_context, file_ops);
+ TEST(collapse_full, khugepaged_context, read_only_file_ops);
+ TEST(collapse_full, khugepaged_context, read_write_file_ops);
TEST(collapse_full, khugepaged_context, shmem_ops);
TEST(collapse_full, madvise_context, anon_ops);
- TEST(collapse_full, madvise_context, file_ops);
+ TEST(collapse_full, madvise_context, read_only_file_ops);
+ TEST(collapse_full, madvise_context, read_write_file_ops);
TEST(collapse_full, madvise_context, shmem_ops);

TEST(collapse_empty, khugepaged_context, anon_ops);
TEST(collapse_empty, madvise_context, anon_ops);

TEST(collapse_single_pte_entry, khugepaged_context, anon_ops);
- TEST(collapse_single_pte_entry, khugepaged_context, file_ops);
+ TEST(collapse_single_pte_entry, khugepaged_context, read_only_file_ops);
+ TEST(collapse_single_pte_entry, khugepaged_context, read_write_file_ops);
TEST(collapse_single_pte_entry, khugepaged_context, shmem_ops);
TEST(collapse_single_pte_entry, madvise_context, anon_ops);
- TEST(collapse_single_pte_entry, madvise_context, file_ops);
+ TEST(collapse_single_pte_entry, madvise_context, read_only_file_ops);
+ TEST(collapse_single_pte_entry, madvise_context, read_write_file_ops);
TEST(collapse_single_pte_entry, madvise_context, shmem_ops);

TEST(collapse_max_ptes_none, khugepaged_context, anon_ops);
- TEST(collapse_max_ptes_none, khugepaged_context, file_ops);
+ TEST(collapse_max_ptes_none, khugepaged_context, read_only_file_ops);
+ TEST(collapse_max_ptes_none, khugepaged_context, read_write_file_ops);
TEST(collapse_max_ptes_none, madvise_context, anon_ops);
- TEST(collapse_max_ptes_none, madvise_context, file_ops);
+ TEST(collapse_max_ptes_none, madvise_context, read_only_file_ops);
+ TEST(collapse_max_ptes_none, madvise_context, read_write_file_ops);

TEST(collapse_single_pte_entry_compound, khugepaged_context, anon_ops);
- TEST(collapse_single_pte_entry_compound, khugepaged_context, file_ops);
+ TEST(collapse_single_pte_entry_compound, khugepaged_context, read_only_file_ops);
+ TEST(collapse_single_pte_entry_compound, khugepaged_context, read_write_file_ops);
TEST(collapse_single_pte_entry_compound, madvise_context, anon_ops);
- TEST(collapse_single_pte_entry_compound, madvise_context, file_ops);
+ TEST(collapse_single_pte_entry_compound, madvise_context, read_only_file_ops);
+ TEST(collapse_single_pte_entry_compound, madvise_context, read_write_file_ops);

TEST(collapse_full_of_compound, khugepaged_context, anon_ops);
- TEST(collapse_full_of_compound, khugepaged_context, file_ops);
+ TEST(collapse_full_of_compound, khugepaged_context, read_only_file_ops);
+ TEST(collapse_full_of_compound, khugepaged_context, read_write_file_ops);
TEST(collapse_full_of_compound, khugepaged_context, shmem_ops);
TEST(collapse_full_of_compound, madvise_context, anon_ops);
- TEST(collapse_full_of_compound, madvise_context, file_ops);
+ TEST(collapse_full_of_compound, madvise_context, read_only_file_ops);
+ TEST(collapse_full_of_compound, madvise_context, read_write_file_ops);
TEST(collapse_full_of_compound, madvise_context, shmem_ops);

TEST(collapse_compound_extreme, khugepaged_context, anon_ops);
@@ -1280,10 +1328,12 @@ int main(int argc, char **argv)
TEST(collapse_max_ptes_shared, madvise_context, anon_ops);

TEST(madvise_collapse_existing_thps, madvise_context, anon_ops);
- TEST(madvise_collapse_existing_thps, madvise_context, file_ops);
+ TEST(madvise_collapse_existing_thps, madvise_context, read_only_file_ops);
+ TEST(madvise_collapse_existing_thps, madvise_context, read_write_file_ops);
TEST(madvise_collapse_existing_thps, madvise_context, shmem_ops);

- TEST(madvise_retracted_page_tables, madvise_context, file_ops);
+ TEST(madvise_retracted_page_tables, madvise_context, read_only_file_ops);
+ TEST(madvise_retracted_page_tables, madvise_context, read_write_file_ops);
TEST(madvise_retracted_page_tables, madvise_context, shmem_ops);

restore_settings(0);
diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh
index d8468451b3a3..50dd6b6d0225 100755
--- a/tools/testing/selftests/mm/run_vmtests.sh
+++ b/tools/testing/selftests/mm/run_vmtests.sh
@@ -489,8 +489,6 @@ CATEGORY="thp" run_test ./khugepaged all:shmem

CATEGORY="thp" run_test ./khugepaged -s 4 all:shmem

-CATEGORY="thp" run_test ./transhuge-stress -d 20
-
# Try to create XFS if not provided
if [ -z "${SPLIT_HUGE_PAGE_TEST_XFS_PATH}" ]; then
if [ "${HAVE_HUGEPAGES}" = "1" ]; then
@@ -507,6 +505,14 @@ if [ -z "${SPLIT_HUGE_PAGE_TEST_XFS_PATH}" ]; then
fi
fi

+if [ -n "${SPLIT_HUGE_PAGE_TEST_XFS_PATH}" ]; then
+CATEGORY="thp" run_test ./khugepaged all:file ${SPLIT_HUGE_PAGE_TEST_XFS_PATH}
+else
+ count_total=$(( count_total + 1 ))
+ count_skip=$(( count_skip + 1 ))
+ echo "[SKIP] ./khugepaged all:file" | tap_prefix
+fi
+
CATEGORY="thp" run_test ./split_huge_page_test ${SPLIT_HUGE_PAGE_TEST_XFS_PATH}

if [ -n "${MOUNTED_XFS}" ]; then
@@ -515,6 +521,8 @@ if [ -n "${MOUNTED_XFS}" ]; then
rm -f ${XFS_IMG}
fi

+CATEGORY="thp" run_test ./transhuge-stress -d 20
+
CATEGORY="thp" run_test ./folio_split_race_test

CATEGORY="migration" run_test ./migration
--
2.43.0