The patch titled
Subject: selftests/mm: hugetlb_fault_after_madv: use default hugetlb page size
has been added to the -mm mm-unstable branch. Its filename is
selftests-mm-hugetlb_fault_after_madv-use-default-hguetlb-page-size.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-mm-hugetlb_fault_after_madv-use-default-hguetlb-page-size.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: David Hildenbrand <david@xxxxxxxxxx>
Subject: selftests/mm: hugetlb_fault_after_madv: use default hugetlb page size
Date: Thu, 26 Sep 2024 17:20:43 +0200
Patch series "selftests/mm: hugetlb_fault_after_madv improvements".
Mario brought to my attention that the hugetlb_fault_after_madv test is
currently always skipped on s390x. Let's adjust the test to be
independent of the default hugetlb page size and while at it, also improve
the test output.
This patch (of 2):
We currently assume that the hugetlb page size is 2 MiB, which is why we
mmap() a 2 MiB range.
Is the default hugetlb size is larger, mmap() will fail because the range
is not suitable. If the default hugetlb size is smaller (e.g., s390x),
mmap() will fail because we would need more than one hugetlb page, but
just asserted that we have exactly one.
So let's simply use the default hugetlb page size instead of hard-coded 2
MiB, so the test isn't unconditionally skipped on architectures like
s390x.
Before this patch on s390x:
$ ./hugetlb_fault_after_madv
1..0 # SKIP Failed to allocated huge page
With this change on s390x:
$ ./hugetlb_fault_after_madv
While at it, make "huge_ptr" static.
Link: https://lkml.kernel.org/r/20240926152044.2205129-1-david@xxxxxxxxxx
Link: https://lkml.kernel.org/r/20240926152044.2205129-2-david@xxxxxxxxxx
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Reported-by: Mario Casquero <mcasquer@xxxxxxxxxx>
Reviewed-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
Cc: Breno Leitao <leitao@xxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/mm/hugetlb_fault_after_madv.c | 14 ++++++----
1 file changed, 9 insertions(+), 5 deletions(-)
--- a/tools/testing/selftests/mm/hugetlb_fault_after_madv.c~selftests-mm-hugetlb_fault_after_madv-use-default-hguetlb-page-size
+++ a/tools/testing/selftests/mm/hugetlb_fault_after_madv.c
@@ -9,10 +9,10 @@
#include "vm_util.h"
#include "../kselftest.h"
-#define MMAP_SIZE (1 << 21)
#define INLOOP_ITER 100
-char *huge_ptr;
+static char *huge_ptr;
+static size_t huge_page_size;
/* Touch the memory while it is being madvised() */
void *touch(void *unused)
@@ -30,7 +30,7 @@ void *madv(void *unused)
usleep(rand() % 10);
for (int i = 0; i < INLOOP_ITER; i++)
- madvise(huge_ptr, MMAP_SIZE, MADV_DONTNEED);
+ madvise(huge_ptr, huge_page_size, MADV_DONTNEED);
return NULL;
}
@@ -47,6 +47,10 @@ int main(void)
srand(getpid());
+ huge_page_size = default_huge_page_size();
+ if (!huge_page_size)
+ ksft_exit_skip("Could not detect default hugetlb page size.");
+
free_hugepages = get_free_hugepages();
if (free_hugepages != 1) {
ksft_exit_skip("This test needs one and only one page to execute. Got %lu\n",
@@ -54,7 +58,7 @@ int main(void)
}
while (max--) {
- huge_ptr = mmap(NULL, MMAP_SIZE, PROT_READ | PROT_WRITE,
+ huge_ptr = mmap(NULL, huge_page_size, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB,
-1, 0);
@@ -66,7 +70,7 @@ int main(void)
pthread_join(thread1, NULL);
pthread_join(thread2, NULL);
- munmap(huge_ptr, MMAP_SIZE);
+ munmap(huge_ptr, huge_page_size);
}
return KSFT_PASS;
_
Patches currently in -mm which might be from david@xxxxxxxxxx are
selftests-mm-hugetlb_fault_after_madv-use-default-hguetlb-page-size.patch
selftests-mm-hugetlb_fault_after_madv-improve-test-output.patch
