From: Chunyu Hu Date: Fri, 12 Sep 2025 01:37:09 +0000 (+0800) Subject: selftests/mm: fix hugepages cleanup too early X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6e296bcf294ee9e8e024158ed1d279cf823eae63;p=thirdparty%2Fkernel%2Fstable.git selftests/mm: fix hugepages cleanup too early Patch series "Fix va_high_addr_switch.sh test failure", v3. These three patches fix the va_high_addr_switch.sh test failure on x86_64. Patch 1 fixes the hugepage setup issue that nr_hugepages is reset too early in run_vmtests.sh and break the later va_high_addr_switch testing. Patch 2 adds hugepage setup in va_high_addr_switch test, so that it can still work if vm_runtests.sh changes the hugepage setup someday. Patch 3 fixes the test failure caused by the hint addr align method change in hugetlb_get_unmapped_area(). This patch (of 3): The nr_hugepgs variable is used to keep the original nr_hugepages at the hugepage setup step at test beginning. After userfaultfd test, a cleaup is executed, both /sys/kernel/mm/hugepages/hugepages-*/nr_hugepages and /proc/sys//vm/nr_hugepages are reset to 'original' value before userfaultfd test starts. Issue here is the value used to restore /proc/sys/vm/nr_hugepages is nr_hugepgs which is the initial value before the vm_runtests.sh runs, not the value before userfaultfd test starts. 'va_high_addr_swith.sh' tests runs after that will possibly see no hugepages available for test, and got EINVAL when mmap(HUGETLB), making the result invalid. And before pkey tests, nr_hugepgs is changed to be used as a temp variable to save nr_hugepages before pkey test, and restore it after pkey tests finish. The original nr_hugepages value is not tracked anymore, so no way to restore it after all tests finish. Add a new variable orig_nr_hugepgs to save the original nr_hugepages, and and restore it to nr_hugepages after all tests finish. And change to use the nr_hugepgs variable to save the /proc/sys/vm/nr_hugeages after hugepage setup, it's also the value before userfaultfd test starts, and the correct value to be restored after userfaultfd finishes. The va_high_addr_switch.sh broken will be resolved. Link: https://lkml.kernel.org/r/20250912013711.3002969-1-chuhu@redhat.com Link: https://lkml.kernel.org/r/20250912013711.3002969-2-chuhu@redhat.com Signed-off-by: Chunyu Hu Acked-by: David Hildenbrand Signed-off-by: Andrew Morton --- diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh index 9e88cc25b9df2..8115fc4526ed9 100755 --- a/tools/testing/selftests/mm/run_vmtests.sh +++ b/tools/testing/selftests/mm/run_vmtests.sh @@ -174,13 +174,13 @@ fi # set proper nr_hugepages if [ -n "$freepgs" ] && [ -n "$hpgsize_KB" ]; then - nr_hugepgs=$(cat /proc/sys/vm/nr_hugepages) + orig_nr_hugepgs=$(cat /proc/sys/vm/nr_hugepages) needpgs=$((needmem_KB / hpgsize_KB)) tries=2 while [ "$tries" -gt 0 ] && [ "$freepgs" -lt "$needpgs" ]; do lackpgs=$((needpgs - freepgs)) echo 3 > /proc/sys/vm/drop_caches - if ! echo $((lackpgs + nr_hugepgs)) > /proc/sys/vm/nr_hugepages; then + if ! echo $((lackpgs + orig_nr_hugepgs)) > /proc/sys/vm/nr_hugepages; then echo "Please run this test as root" exit $ksft_skip fi @@ -191,6 +191,7 @@ if [ -n "$freepgs" ] && [ -n "$hpgsize_KB" ]; then done < /proc/meminfo tries=$((tries - 1)) done + nr_hugepgs=$(cat /proc/sys/vm/nr_hugepages) if [ "$freepgs" -lt "$needpgs" ]; then printf "Not enough huge pages available (%d < %d)\n" \ "$freepgs" "$needpgs" @@ -540,6 +541,10 @@ CATEGORY="page_frag" run_test ./test_page_frag.sh nonaligned CATEGORY="rmap" run_test ./rmap +if [ "${HAVE_HUGEPAGES}" = 1 ]; then + echo "$orig_nr_hugepgs" > /proc/sys/vm/nr_hugepages +fi + echo "SUMMARY: PASS=${count_pass} SKIP=${count_skip} FAIL=${count_fail}" | tap_prefix echo "1..${count_total}" | tap_output