The patch titled Subject: selftests/mm: fix charge_reserved_hugetlb.sh test has been added to the -mm mm-unstable branch. Its filename is selftests-mm-fix-charge_reserved_hugetlbsh-test.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-mm-fix-charge_reserved_hugetlbsh-test.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: David Hildenbrand <david@xxxxxxxxxx> Subject: selftests/mm: fix charge_reserved_hugetlb.sh test Date: Wed, 21 Aug 2024 14:31:15 +0200 Currently, running the charge_reserved_hugetlb.sh selftest we can sometimes observe something like: $ ./charge_reserved_hugetlb.sh -cgroup-v2 ... write_result is 0 After write: hugetlb_usage=0 reserved_usage=10485760 killing write_to_hugetlbfs Received 2. Deleting the memory Detach failure: Invalid argument umount: /mnt/huge: target is busy. Both cases are issues in the test. While the unmount error seems to be racy, it will make the test fail: $ ./run_vmtests.sh -t hugetlb ... # [FAIL] not ok 10 charge_reserved_hugetlb.sh -cgroup-v2 # exit=32 The issue is that we are not waiting for the write_to_hugetlbfs process to quit. So it might still have a hugetlbfs file open, about which umount is not happy. Fix that by making "killall" wait for the process to quit. The other error ("Detach failure: Invalid argument") does not seem to result in a test error, but is misleading. Turns out write_to_hugetlbfs.c unconditionally tries to cleanup using shmdt(), even when we only mmap()'ed a hugetlb file. Even worse, shmaddr is never even set for the SHM case. Fix that as well. With this change it seems to work as expected. Link: https://lkml.kernel.org/r/20240821123115.2068812-1-david@xxxxxxxxxx Fixes: 29750f71a9b4 ("hugetlb_cgroup: add hugetlb_cgroup reservation tests") Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> Reported-by: Mario Casquero <mcasquer@xxxxxxxxxx> Reviewed-by: Mina Almasry <almasrymina@xxxxxxxxxx> Cc: Shuah Khan <shuah@xxxxxxxxxx> Cc: Muchun Song <muchun.song@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- tools/testing/selftests/mm/charge_reserved_hugetlb.sh | 2 tools/testing/selftests/mm/write_to_hugetlbfs.c | 21 +++++----- 2 files changed, 13 insertions(+), 10 deletions(-) --- a/tools/testing/selftests/mm/charge_reserved_hugetlb.sh~selftests-mm-fix-charge_reserved_hugetlbsh-test +++ a/tools/testing/selftests/mm/charge_reserved_hugetlb.sh @@ -254,7 +254,7 @@ function cleanup_hugetlb_memory() { local cgroup="$1" if [[ "$(pgrep -f write_to_hugetlbfs)" != "" ]]; then echo killing write_to_hugetlbfs - killall -2 write_to_hugetlbfs + killall -2 --wait write_to_hugetlbfs wait_for_hugetlb_memory_to_get_depleted $cgroup fi set -e --- a/tools/testing/selftests/mm/write_to_hugetlbfs.c~selftests-mm-fix-charge_reserved_hugetlbsh-test +++ a/tools/testing/selftests/mm/write_to_hugetlbfs.c @@ -28,7 +28,7 @@ enum method { /* Global variables. */ static const char *self; -static char *shmaddr; +static int *shmaddr; static int shmid; /* @@ -47,15 +47,17 @@ void sig_handler(int signo) { printf("Received %d.\n", signo); if (signo == SIGINT) { - printf("Deleting the memory\n"); - if (shmdt((const void *)shmaddr) != 0) { - perror("Detach failure"); + if (shmaddr) { + printf("Deleting the memory\n"); + if (shmdt((const void *)shmaddr) != 0) { + perror("Detach failure"); + shmctl(shmid, IPC_RMID, NULL); + exit(4); + } + shmctl(shmid, IPC_RMID, NULL); - exit(4); + printf("Done deleting the memory\n"); } - - shmctl(shmid, IPC_RMID, NULL); - printf("Done deleting the memory\n"); } exit(2); } @@ -211,7 +213,8 @@ int main(int argc, char **argv) shmctl(shmid, IPC_RMID, NULL); exit(2); } - printf("shmaddr: %p\n", ptr); + shmaddr = ptr; + printf("shmaddr: %p\n", shmaddr); break; default: _ Patches currently in -mm which might be from david@xxxxxxxxxx are mm-turn-use_split_pte_ptlocks-use_split_pte_ptlocks-into-kconfig-options.patch mm-hugetlb-enforce-that-pmd-pt-sharing-has-split-pmd-pt-locks.patch powerpc-8xx-document-and-enforce-that-split-pt-locks-are-not-used.patch mm-simplify-arch_make_folio_accessible.patch mm-gup-convert-to-arch_make_folio_accessible.patch s390-uv-drop-arch_make_page_accessible.patch mm-hugetlb-remove-hugetlb_follow_page_mask-leftover.patch mm-rmap-cleanup-partially-mapped-handling-in-__folio_remove_rmap.patch mm-clarify-folio_likely_mapped_shared-documentation-for-ksm-folios.patch mm-provide-vm_normal_pagefolio_pmd-with-config_pgtable_has_huge_leaves.patch mm-pagewalk-introduce-folio_walk_start-folio_walk_end.patch mm-migrate-convert-do_pages_stat_array-from-follow_page-to-folio_walk.patch mm-migrate-convert-add_page_for_migration-from-follow_page-to-folio_walk.patch mm-ksm-convert-get_mergeable_page-from-follow_page-to-folio_walk.patch mm-ksm-convert-scan_get_next_rmap_item-from-follow_page-to-folio_walk.patch mm-huge_memory-convert-split_huge_pages_pid-from-follow_page-to-folio_walk.patch mm-huge_memory-convert-split_huge_pages_pid-from-follow_page-to-folio_walk-fix.patch s390-uv-convert-gmap_destroy_page-from-follow_page-to-folio_walk.patch s390-mm-fault-convert-do_secure_storage_access-from-follow_page-to-folio_walk.patch mm-remove-follow_page.patch mm-ksm-convert-break_ksm-from-walk_page_range_vma-to-folio_walk.patch mm-rmap-minimize-folio-_nr_pages_mapped-updates-when-batching-pte-unmapping.patch mm-rmap-use-folio-_mapcount-for-small-folios.patch mm-always-inline-_compound_head-with-config_hugetlb_page_optimize_vmemmap=y.patch selftests-mm-fix-charge_reserved_hugetlbsh-test.patch