+ selftests-mm-transhuge-stress-check-duration-inside-page-loop.patch added to mm-new branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: selftests/mm: transhuge-stress: check duration inside page loop
has been added to the -mm mm-new branch.  Its filename is
     selftests-mm-transhuge-stress-check-duration-inside-page-loop.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-mm-transhuge-stress-check-duration-inside-page-loop.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

The mm-new branch of mm.git is not included in linux-next

If a few days of testing in mm-new is successful, the patch will me moved
into mm.git's mm-unstable branch, which is included in linux-next

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------------------------------------------------------
From: Sarthak Sharma <sarthak.sharma@arm.com>
Subject: selftests/mm: transhuge-stress: check duration inside page loop
Date: Mon, 20 Jul 2026 16:01:05 +0530

transhuge-stress.c currently scans memory equal to RAM by default, in
jumps of hugepage size, trying to allocate and split a THP at each step. 
After the entire range is covered, it checks whether elapsed time is
greater than the duration.  But it is possible that the THP work it does
takes time more than the duration itself, causing the test to exceed the
CI timeout.

Check the elapsed time after each THP operation.  If the duration has
elapsed, break and end the test.  Adjust the statistics calculations to
accommodate partially completed passes.  Also, reject sizes which are
smaller than a huge page.

Link: https://lore.kernel.org/20260720103105.169955-1-sarthak.sharma@arm.com
Signed-off-by: Sarthak Sharma <sarthak.sharma@arm.com>
Reported-by: Aishwarya TCV <aishwarya.tcv@arm.com>
Suggested-by: Dev Jain <dev.jain@arm.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 tools/testing/selftests/mm/transhuge-stress.c |   28 ++++++++++++----
 1 file changed, 22 insertions(+), 6 deletions(-)

--- a/tools/testing/selftests/mm/transhuge-stress.c~selftests-mm-transhuge-stress-check-duration-inside-page-loop
+++ a/tools/testing/selftests/mm/transhuge-stress.c
@@ -35,6 +35,7 @@ int main(int argc, char **argv)
 	size_t map_len;
 	int pagemap_fd;
 	int duration = 0;
+	double elapsed = 0;
 
 	ksft_print_header();
 
@@ -60,8 +61,6 @@ int main(int argc, char **argv)
 			len = atoll(argv[i]) << 20;
 	}
 
-	ksft_set_plan(1);
-
 	if (name) {
 		backing_fd = open(name, O_RDWR);
 		if (backing_fd == -1)
@@ -78,6 +77,10 @@ int main(int argc, char **argv)
 		ksft_exit_fail_msg("open pagemap\n");
 
 	len -= len % HPAGE_SIZE;
+	if (len == 0)
+		ksft_exit_fail_msg("len must be at least %d MiB\n",
+			HPAGE_SIZE >> 20);
+
 	ptr = mmap(NULL, len + HPAGE_SIZE, PROT_RW, mmap_flags, backing_fd, 0);
 	if (ptr == MAP_FAILED)
 		ksft_exit_fail_msg("initial mmap");
@@ -91,6 +94,7 @@ int main(int argc, char **argv)
 	if (!map)
 		ksft_exit_fail_msg("map malloc\n");
 
+	ksft_set_plan(1);
 	clock_gettime(CLOCK_MONOTONIC, &start);
 
 	while (1) {
@@ -125,16 +129,28 @@ int main(int argc, char **argv)
 			/* split transhuge page, keep last page */
 			if (madvise(p, HPAGE_SIZE - psize(), MADV_DONTNEED))
 				ksft_exit_fail_msg("MADV_DONTNEED");
+
+			if (duration > 0) {
+				clock_gettime(CLOCK_MONOTONIC, &b);
+				elapsed = b.tv_sec - start.tv_sec +
+					(b.tv_nsec - start.tv_nsec) / 1000000000.;
+				if (elapsed >= duration)
+					break;
+			}
 		}
 		clock_gettime(CLOCK_MONOTONIC, &b);
 		s = b.tv_sec - a.tv_sec + (b.tv_nsec - a.tv_nsec) / 1000000000.;
 
 		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),
-			       nr_succeed, nr_failed, nr_pages);
+				"%4d succeed, %4d failed, %4d different pages\n",
+				s, s * 1000 / (nr_failed + nr_succeed),
+				s > 0 ?
+					(double)(nr_failed + nr_succeed) *
+					(HPAGE_SIZE >> 20) / s :
+					0.0,
+				nr_succeed, nr_failed, nr_pages);
 
-		if (duration > 0 && b.tv_sec - start.tv_sec >= duration) {
+		if (duration > 0 && elapsed >= duration) {
 			ksft_test_result_pass("Completed\n");
 			ksft_finished();
 		}
_

Patches currently in -mm which might be from sarthak.sharma@arm.com are

selftests-mm-transhuge-stress-check-duration-inside-page-loop.patch