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selftests/mm: fix hugepages cleanup too early

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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 <chuhu@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Chunyu Hu 2025-09-12 09:37:09 +08:00 committed by Andrew Morton
parent 6028372689
commit 6e296bcf29
1 changed files with 7 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
tools/testing/selftests/mm/run_vmtests.sh
View File

@ -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