The quilt patch titled Subject: selftests/mm: cow: print ksft header before printing anything else has been removed from the -mm tree. Its filename was selftests-mm-cow-print-ksft-header-before-printing-anything-else.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: David Hildenbrand <david@xxxxxxxxxx> Subject: selftests/mm: cow: print ksft header before printing anything else Date: Wed, 6 Dec 2023 11:35:58 +0100 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> --- tools/testing/selftests/mm/cow.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/tools/testing/selftests/mm/cow.c~selftests-mm-cow-print-ksft-header-before-printing-anything-else +++ a/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()); _ Patches currently in -mm which might be from david@xxxxxxxxxx are