Commit 49a4e7186b08 ("selftests/mm: thuge-gen: add setup of HugeTLB pages")
changed thuge-gen test to use common functions for reading hugetlb
attributes from sysfs, but it missed that the original read_free() function
special cased PAGE_SIZE tests.
For PAGE_SIZE tests, failure to read sysfs was ignored and read_free()
returned 0.
This allowed test_shmget() to essentially skip the check of how many huge
pages was consumed when it ran with PAGE_SIZE.
Commit 3199b0c09efa ("selftests/mm: fix read_file() return value check")
fixed checks for read_file() return value and this exposed the issue in
test_shmget() that checks the number of free hugetlb pages even for
PAGE_SIZE test, tries to access
/sys/kernel/mm/hugepages/hugepages-<PAGE_SIZE>/free_hugepages
and obviously fails there.
Gate the checks for free huge pages on size != getpagesize() and initialize
before and after variables to values matching PAGE_SIZE test.
Fixes: 49a4e7186b08 ("selftests/mm: thuge-gen: add setup of HugeTLB pages")
Acked-by: David Hildenbrand (Arm) <[email protected]>
Reviewed-by: Sarthak Sharma <[email protected]>
Acked-by: Lorenzo Stoakes (ARM) <[email protected]>
Signed-off-by: Mike Rapoport (Microsoft) <[email protected]>
---
v2 changes:
* Correct the commit message
v1:
https://patch.msgid.link/[email protected]
---
tools/testing/selftests/mm/thuge-gen.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/tools/testing/selftests/mm/thuge-gen.c
b/tools/testing/selftests/mm/thuge-gen.c
index 22b9c2f1c35d..50d0805b65db 100644
--- a/tools/testing/selftests/mm/thuge-gen.c
+++ b/tools/testing/selftests/mm/thuge-gen.c
@@ -71,12 +71,16 @@ void test_mmap(unsigned long size, unsigned flags)
void test_shmget(unsigned long size, unsigned flags)
{
- int id;
- unsigned long before, after;
+ /* values for PAGE_SIZE test */
+ unsigned long before = NUM_PAGES;
+ unsigned long after = 0;
struct shm_info i;
char *map;
+ int id;
+
+ if (size != getpagesize())
+ before = hugetlb_free_pages(size);
- before = hugetlb_free_pages(size);
id = shmget(IPC_PRIVATE, size * NUM_PAGES, IPC_CREAT|0600|flags);
if (id < 0) {
if (errno == EPERM) {
@@ -97,10 +101,11 @@ void test_shmget(unsigned long size, unsigned flags)
shmctl(id, IPC_RMID, NULL);
memset(map, 0xff, size*NUM_PAGES);
- after = hugetlb_free_pages(size);
+ if (size != getpagesize())
+ after = hugetlb_free_pages(size);
show(size);
- ksft_test_result(size == getpagesize() || (before - after) == NUM_PAGES,
+ ksft_test_result((before - after) == NUM_PAGES,
"%s: mmap %lu %x\n", __func__, size, flags);
if (shmdt(map))
ksft_exit_fail_msg("%s: shmdt: %s\n", __func__,
strerror(errno));
---
base-commit: 17e5919bdca144d4e67337f53bf57d7811f62192
change-id: 20260809-selftests-thuge-gen-fix-5ac05f56307c
--
Sincerely yours,
Mike.
