This is a note to let you know that I've just added the patch titled
selftests/mm: cow: print ksft header before printing anything else
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
selftests-mm-cow-print-ksft-header-before-printing-a.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit a90c3c7bc1713f0515c3bfa7dc9fbb5ca31fa72b
Author: David Hildenbrand <david@xxxxxxxxxx>
Date: Wed Dec 6 11:35:58 2023 +0100
selftests/mm: cow: print ksft header before printing anything else
[ Upstream commit a6fcd57cf2df409d35e9225b8dbad6f937b28df0 ]
Doing a ksft_print_msg() before the ksft_print_header() seems to confuse
the ksft framework in a strange way: running the test on the cmdline
results in the expected output.
But piping the output somewhere else, results in some odd output,
whereby we repeatedly get the same info printed:
# [INFO] detected THP size: 2048 KiB
# [INFO] detected hugetlb page size: 2048 KiB
# [INFO] detected hugetlb page size: 1048576 KiB
# [INFO] huge zeropage is enabled
TAP version 13
1..190
# [INFO] Anonymous memory tests in private mappings
# [RUN] Basic COW after fork() ... with base page
# [INFO] detected THP size: 2048 KiB
# [INFO] detected hugetlb page size: 2048 KiB
# [INFO] detected hugetlb page size: 1048576 KiB
# [INFO] huge zeropage is enabled
TAP version 13
1..190
# [INFO] Anonymous memory tests in private mappings
# [RUN] Basic COW after fork() ... with base page
ok 1 No leak from parent into child
# [RUN] Basic COW after fork() ... with swapped out base page
# [INFO] detected THP size: 2048 KiB
# [INFO] detected hugetlb page size: 2048 KiB
# [INFO] detected hugetlb page size: 1048576 KiB
# [INFO] huge zeropage is enabled
Doing the ksft_print_header() first seems to resolve that and gives us
the output we expect:
TAP version 13
# [INFO] detected THP size: 2048 KiB
# [INFO] detected hugetlb page size: 2048 KiB
# [INFO] detected hugetlb page size: 1048576 KiB
# [INFO] huge zeropage is enabled
1..190
# [INFO] Anonymous memory tests in private mappings
# [RUN] Basic COW after fork() ... with base page
ok 1 No leak from parent into child
# [RUN] Basic COW after fork() ... with swapped out base page
ok 2 No leak from parent into child
# [RUN] Basic COW after fork() ... with THP
ok 3 No leak from parent into child
# [RUN] Basic COW after fork() ... with swapped-out THP
ok 4 No leak from parent into child
# [RUN] Basic COW after fork() ... with PTE-mapped THP
ok 5 No leak from parent into child
Link: https://lkml.kernel.org/r/20231206103558.38040-1-david@xxxxxxxxxx
Fixes: f4b5fd6946e2 ("selftests/vm: anon_cow: THP tests")
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Reported-by: Nico Pache <npache@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/testing/selftests/mm/cow.c b/tools/testing/selftests/mm/cow.c
index 7324ce5363c0c..6f2f839904416 100644
--- a/tools/testing/selftests/mm/cow.c
+++ b/tools/testing/selftests/mm/cow.c
@@ -1680,6 +1680,8 @@ int main(int argc, char **argv)
{
int err;
+ ksft_print_header();
+
pagesize = getpagesize();
thpsize = read_pmd_pagesize();
if (thpsize)
@@ -1689,7 +1691,6 @@ int main(int argc, char **argv)
ARRAY_SIZE(hugetlbsizes));
detect_huge_zeropage();
- ksft_print_header();
ksft_set_plan(ARRAY_SIZE(anon_test_cases) * tests_per_anon_test_case() +
ARRAY_SIZE(anon_thp_test_cases) * tests_per_anon_thp_test_case() +
ARRAY_SIZE(non_anon_test_cases) * tests_per_non_anon_test_case());
