[PATCH v3 2/3] kselftest: mm: remove HPAGE_SIZE and HPAGE_SHIFT macro
From: Yeoreum Yun
Date: Mon Sep 14 2026 - 03:43:23 EST
HPAGE_SIZE and HPAGE_SHIFT macro is written based on the 4KB PAGE_SIZE.
When this macro is used in some test, test result would be strange in
the system where PAGE_SIZE is more then 4KB.
Here is the example with transhuge-stress test with 16KB PAGE_SIZE:
transhuge-stress: allocate 61073 transhuge pages, using 122146 MiB virtual memory and 1908 MiB of ram
3.292 s/loop, 0.054 ms/page, 37106.002 MiB/s 2566 succeed, 58507 failed, 2566 different pages
0.591 s/loop, 0.010 ms/page, 206850.792 MiB/s 0 succeed, 61073 failed, 0 different pages
0.527 s/loop, 0.009 ms/page, 231895.107 MiB/s 0 succeed, 61073 failed, 0 different pages
0.527 s/loop, 0.009 ms/page, 231839.704 MiB/s 0 succeed, 61073 failed, 0 different pages
0.528 s/loop, 0.009 ms/page, 231544.782 MiB/s 0 succeed, 61073 failed, 0 different pages
0.528 s/loop, 0.009 ms/page, 231462.074 MiB/s 0 succeed, 61073 failed, 0 different pages
0.527 s/loop, 0.009 ms/page, 231770.300 MiB/s 0 succeed, 61073 failed, 0 different pages
...
ok 1 Completed
Remove the HPAGE_SIZE and HPAGE_SHIFT macro and introduce pmd_pshift()
helper to get the HPAGE_SHIFT properly. For HPAGE_SIZE, use pre-existing
helper, pmd_psize().
Also, run the KSM_MERGE_TIME_HUGE_PAGES test with a size of 512 MiB,
which is the least common multiple of the PMD sizes for 4 KiB, 16 KiB,
and 64 KiB base pages. Since allocate_transhuge() allocates mappings in
PMD-sized units, the test may fail with the previous size of 100 MiB,
which is not a multiple of the PMD size when the base page size is
16 KiB or 64 KiB.
After this patch, output of transhuge-stress:
transhuge-stress: allocate 3817 transhuge pages, using 122146 MiB virtual memory and 119 MiB of ram
2.558 s/loop, 0.670 ms/page, 47755.759 MiB/s 2585 succeed, 1232 failed, 2585 different pages
2.640 s/loop, 0.692 ms/page, 46268.432 MiB/s 2585 succeed, 1232 failed, 2585 different pages
2.635 s/loop, 0.690 ms/page, 46360.298 MiB/s 2585 succeed, 1232 failed, 2585 different pages
2.782 s/loop, 0.729 ms/page, 43899.795 MiB/s 2616 succeed, 1201 failed, 2616 different pages
2.692 s/loop, 0.705 ms/page, 45380.876 MiB/s 2627 succeed, 1190 failed, 2627 different pages
2.612 s/loop, 0.684 ms/page, 46765.812 MiB/s 2628 succeed, 1189 failed, 2628 different pages
2.683 s/loop, 0.703 ms/page, 45520.990 MiB/s 2630 succeed, 1187 failed, 2630 different pages
2.727 s/loop, 0.714 ms/page, 44789.321 MiB/s 2631 succeed, 1186 failed, 2631 different pages
...
ok 1 Completed
Suggested-by: Lorenzo Stoakes (ARM) <ljs@xxxxxxxxxx>
Signed-off-by: Yeoreum Yun <yeoreum.yun@xxxxxxx>
---
tools/testing/selftests/mm/guard-regions.c | 11 ++++++--
tools/testing/selftests/mm/ksm_tests.c | 16 +++++++-----
tools/testing/selftests/mm/run_vmtests.sh | 4 +--
tools/testing/selftests/mm/transhuge-stress.c | 25 +++++++++++--------
tools/testing/selftests/mm/vm_util.c | 36 ++++++++++++++++++++++++---
tools/testing/selftests/mm/vm_util.h | 9 +++----
6 files changed, 71 insertions(+), 30 deletions(-)
diff --git a/tools/testing/selftests/mm/guard-regions.c b/tools/testing/selftests/mm/guard-regions.c
index b724d62d2b75..eee29ef88cb2 100644
--- a/tools/testing/selftests/mm/guard-regions.c
+++ b/tools/testing/selftests/mm/guard-regions.c
@@ -2195,14 +2195,21 @@ TEST_F(guard_regions, pagemap_scan)
TEST_F(guard_regions, collapse)
{
const unsigned long page_size = self->page_size;
- const unsigned long size = 2 * HPAGE_SIZE;
- const unsigned long num_pages = size / page_size;
+ const uint64_t hpage_size = pmd_psize();
+ unsigned long size;
+ unsigned long num_pages;
char *ptr;
int i;
if (!thp_available())
SKIP(return, "Transparent Hugepages not available\n");
+ if (!hpage_size)
+ ksft_exit_fail_msg("reading hpage_size failed\n");
+
+ size = 2 * hpage_size;
+ num_pages = size / page_size;
+
/* Need file to be correct size for tests for non-anon. */
if (variant->backing != ANON_BACKED)
ASSERT_EQ(ftruncate(self->fd, size), 0);
diff --git a/tools/testing/selftests/mm/ksm_tests.c b/tools/testing/selftests/mm/ksm_tests.c
index 5fd7792a0d47..617e31138af0 100644
--- a/tools/testing/selftests/mm/ksm_tests.c
+++ b/tools/testing/selftests/mm/ksm_tests.c
@@ -521,19 +521,23 @@ static int ksm_merge_hugepages_time(int merge_type, int mapping, int prot,
struct timespec start_time, end_time;
unsigned long scan_time_ns;
int pagemap_fd, n_normal_pages, n_huge_pages;
+ const uint64_t hpage_size = pmd_psize();
if (!thp_is_enabled()) {
ksft_print_msg("Transparent Hugepages not available\n");
return KSFT_SKIP;
}
+ if (!hpage_size)
+ ksft_exit_fail_msg("reading hpage_size failed\n");
+
map_size *= MB;
size_t len = map_size;
- len -= len % HPAGE_SIZE;
- map_ptr_orig = mmap(NULL, len + HPAGE_SIZE, PROT_READ | PROT_WRITE,
+ len -= len % hpage_size;
+ map_ptr_orig = mmap(NULL, len + hpage_size, PROT_READ | PROT_WRITE,
MAP_ANONYMOUS | MAP_NORESERVE | MAP_PRIVATE, -1, 0);
- map_ptr = map_ptr_orig + HPAGE_SIZE - (uintptr_t)map_ptr_orig % HPAGE_SIZE;
+ map_ptr = map_ptr_orig + hpage_size - (uintptr_t)map_ptr_orig % hpage_size;
if (map_ptr_orig == MAP_FAILED)
err(2, "initial mmap");
@@ -547,7 +551,7 @@ static int ksm_merge_hugepages_time(int merge_type, int mapping, int prot,
n_normal_pages = 0;
n_huge_pages = 0;
- for (void *p = map_ptr; p < map_ptr + len; p += HPAGE_SIZE) {
+ for (void *p = map_ptr; p < map_ptr + len; p += hpage_size) {
if (allocate_transhuge(p, pagemap_fd) < 0)
n_normal_pages++;
else
@@ -578,11 +582,11 @@ static int ksm_merge_hugepages_time(int merge_type, int mapping, int prot,
ksft_print_msg("Average speed: %.3f MiB/s\n", (map_size / MB) /
((double)scan_time_ns / NSEC_PER_SEC));
- munmap(map_ptr_orig, len + HPAGE_SIZE);
+ munmap(map_ptr_orig, len + hpage_size);
return KSFT_PASS;
err_out:
- munmap(map_ptr_orig, len + HPAGE_SIZE);
+ munmap(map_ptr_orig, len + hpage_size);
return KSFT_FAIL;
}
diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh
index 0935dbef4884..d7beedd5e178 100755
--- a/tools/testing/selftests/mm/run_vmtests.sh
+++ b/tools/testing/selftests/mm/run_vmtests.sh
@@ -378,8 +378,8 @@ fi
CATEGORY="memfd_secret" run_test ./memfd_secret
fi
-# KSM KSM_MERGE_TIME_HUGE_PAGES test with size of 100
-CATEGORY="ksm" run_test ./ksm_tests -H -s 100
+# KSM KSM_MERGE_TIME_HUGE_PAGES test with size of 512
+CATEGORY="ksm" run_test ./ksm_tests -H -s 512
# KSM KSM_MERGE_TIME test with size of 100
CATEGORY="ksm" run_test ./ksm_tests -P -s 100
# KSM MADV_MERGEABLE test with 10 identical pages
diff --git a/tools/testing/selftests/mm/transhuge-stress.c b/tools/testing/selftests/mm/transhuge-stress.c
index 8eb0c5630e7e..40ca224a61f4 100644
--- a/tools/testing/selftests/mm/transhuge-stress.c
+++ b/tools/testing/selftests/mm/transhuge-stress.c
@@ -35,12 +35,17 @@ int main(int argc, char **argv)
size_t map_len;
int pagemap_fd;
int duration = 0;
+ const uint64_t hpage_size = pmd_psize();
+ const uint64_t hpage_shift = pmd_pshift();
ksft_print_header();
if (!thp_is_enabled())
ksft_exit_skip("Transparent Hugepages not available\n");
+ if (!hpage_size || !hpage_shift)
+ ksft_exit_fail_msg("reading hpage_size failed\n");
+
ram = sysconf(_SC_PHYS_PAGES);
if (ram > SIZE_MAX / psize() / 4)
ram = SIZE_MAX / 4;
@@ -70,23 +75,23 @@ int main(int argc, char **argv)
}
warnx("allocate %zd transhuge pages, using %zd MiB virtual memory"
- " and %zd MiB of ram", len >> HPAGE_SHIFT, len >> 20,
- ram >> (20 + HPAGE_SHIFT - pshift() - 1));
+ " and %zd MiB of ram", len >> hpage_shift, len >> 20,
+ ram >> (20 + hpage_shift - pshift() - 1));
pagemap_fd = open("/proc/self/pagemap", O_RDONLY);
if (pagemap_fd < 0)
ksft_exit_fail_msg("open pagemap\n");
- len -= len % HPAGE_SIZE;
- ptr = mmap(NULL, len + HPAGE_SIZE, PROT_RW, mmap_flags, backing_fd, 0);
+ len -= len % hpage_size;
+ ptr = mmap(NULL, len + hpage_size, PROT_RW, mmap_flags, backing_fd, 0);
if (ptr == MAP_FAILED)
ksft_exit_fail_msg("initial mmap");
- ptr += HPAGE_SIZE - (uintptr_t)ptr % HPAGE_SIZE;
+ ptr += hpage_size - (uintptr_t)ptr % hpage_size;
if (madvise(ptr, len, MADV_HUGEPAGE))
ksft_exit_fail_msg("MADV_HUGEPAGE");
- map_len = ram >> (HPAGE_SHIFT - 1);
+ map_len = ram >> (hpage_shift - 1);
map = malloc(map_len);
if (!map)
ksft_exit_fail_msg("map malloc\n");
@@ -99,7 +104,7 @@ int main(int argc, char **argv)
memset(map, 0, map_len);
clock_gettime(CLOCK_MONOTONIC, &a);
- for (p = ptr; p < ptr + len; p += HPAGE_SIZE) {
+ for (p = ptr; p < ptr + len; p += hpage_size) {
int64_t pfn;
pfn = allocate_transhuge(p, pagemap_fd);
@@ -107,7 +112,7 @@ int main(int argc, char **argv)
if (pfn < 0) {
nr_failed++;
} else {
- size_t idx = pfn >> (HPAGE_SHIFT - pshift());
+ size_t idx = pfn >> (hpage_shift - pshift());
nr_succeed++;
if (idx >= map_len) {
@@ -123,7 +128,7 @@ int main(int argc, char **argv)
}
/* split transhuge page, keep last page */
- if (madvise(p, HPAGE_SIZE - psize(), MADV_DONTNEED))
+ if (madvise(p, hpage_size - psize(), MADV_DONTNEED))
ksft_exit_fail_msg("MADV_DONTNEED");
}
clock_gettime(CLOCK_MONOTONIC, &b);
@@ -131,7 +136,7 @@ int main(int argc, char **argv)
ksft_print_msg("%.3f s/loop, %.3f ms/page, %10.3f MiB/s\t"
"%4d succeed, %4d failed, %4d different pages\n",
- s, s * 1000 / (len >> HPAGE_SHIFT), len / s / (1 << 20),
+ s, s * 1000 / (len >> hpage_shift), len / s / (1 << 20),
nr_succeed, nr_failed, nr_pages);
if (duration > 0 && b.tv_sec - start.tv_sec >= duration) {
diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c
index e712a980851c..fd1432dc6152 100644
--- a/tools/testing/selftests/mm/vm_util.c
+++ b/tools/testing/selftests/mm/vm_util.c
@@ -21,6 +21,8 @@
unsigned int __page_size;
unsigned int __page_shift;
+uint64_t __pmd_psize;
+uint64_t __pmd_pshift;
uint64_t pagemap_get_entry(int fd, char *start)
{
@@ -161,6 +163,9 @@ uint64_t pmd_psize(void)
char buf[20];
ssize_t num_read;
+ if (__pmd_psize)
+ return __pmd_psize;
+
fd = open(PMD_SIZE_FILE_PATH, O_RDONLY);
if (fd == -1)
return 0;
@@ -173,7 +178,25 @@ uint64_t pmd_psize(void)
buf[num_read] = '\0';
close(fd);
- return strtoul(buf, NULL, 10);
+ __pmd_psize = strtoul(buf, NULL, 10);
+
+ return __pmd_psize;
+}
+
+uint64_t pmd_pshift(void)
+{
+ if (__pmd_pshift)
+ return __pmd_pshift;
+
+ if (!__pmd_psize)
+ __pmd_psize = pmd_psize();
+
+ if (!__pmd_psize)
+ return 0;
+
+ __pmd_pshift = ffsl(__pmd_psize) - 1;
+
+ return __pmd_pshift;
}
unsigned long rss_anon(void)
@@ -452,14 +475,19 @@ bool check_huge_shmem(void *addr, size_t len, int nr_hpages, uint64_t hpage_size
int64_t allocate_transhuge(void *ptr, int pagemap_fd)
{
uint64_t ent[2];
+ const uint64_t hpage_size = pmd_psize();
+ const uint64_t hpage_shift = pmd_pshift();
+
+ if (!hpage_size || !hpage_shift)
+ return -1;
/* drop pmd */
- if (mmap(ptr, HPAGE_SIZE, PROT_READ | PROT_WRITE,
+ if (mmap(ptr, hpage_size, PROT_READ | PROT_WRITE,
MAP_FIXED | MAP_ANONYMOUS |
MAP_NORESERVE | MAP_PRIVATE, -1, 0) != ptr)
ksft_exit_fail_msg("mmap transhuge\n");
- if (madvise(ptr, HPAGE_SIZE, MADV_HUGEPAGE))
+ if (madvise(ptr, hpage_size, MADV_HUGEPAGE))
ksft_exit_fail_msg("MADV_HUGEPAGE\n");
/* allocate transparent huge page */
@@ -471,7 +499,7 @@ int64_t allocate_transhuge(void *ptr, int pagemap_fd)
if (PAGEMAP_PRESENT(ent[0]) && PAGEMAP_PRESENT(ent[1]) &&
PAGEMAP_PFN(ent[0]) + 1 == PAGEMAP_PFN(ent[1]) &&
- !(PAGEMAP_PFN(ent[0]) & ((1 << (HPAGE_SHIFT - pshift())) - 1)))
+ !(PAGEMAP_PFN(ent[0]) & ((1 << (hpage_shift - pshift())) - 1)))
return PAGEMAP_PFN(ent[0]);
return -1;
diff --git a/tools/testing/selftests/mm/vm_util.h b/tools/testing/selftests/mm/vm_util.h
index a40e40c820ef..71af4804f8f2 100644
--- a/tools/testing/selftests/mm/vm_util.h
+++ b/tools/testing/selftests/mm/vm_util.h
@@ -31,6 +31,8 @@
extern unsigned int __page_size;
extern unsigned int __page_shift;
+extern uint64_t __pmd_psize;
+extern uint64_t __pmd_pshift;
/*
* Represents an open fd and PROCMAP_QUERY state for binary (via ioctl)
@@ -89,6 +91,7 @@ unsigned long pagemap_get_pfn(int fd, char *start);
void clear_softdirty(void);
bool check_for_pattern(FILE *fp, const char *pattern, char *buf, size_t len);
uint64_t pmd_psize(void);
+uint64_t pmd_pshift(void);
unsigned long rss_anon(void);
bool check_huge_anon(void *addr, size_t len, int nr_hpages, uint64_t hpage_size);
bool check_huge_file(void *addr, size_t len, int nr_hpages, uint64_t hpage_size);
@@ -157,12 +160,6 @@ int ksm_stop(void);
int get_hardware_corrupted_size(unsigned long *val);
int unpoison_memory(unsigned long pfn);
-/*
- * On ppc64 this will only work with radix 2M hugepage size
- */
-#define HPAGE_SHIFT 21
-#define HPAGE_SIZE (1 << HPAGE_SHIFT)
-
#define PAGEMAP_PRESENT(ent) (((ent) & (1ull << 63)) != 0)
#define PAGEMAP_PFN(ent) ((ent) & ((1ull << 55) - 1))
--
2.43.0