On 27.08.25 09:52, Chunyu Hu wrote:
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 nr_hugepgs_origin 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.
Signed-off-by: Chunyu Hu <ch...@redhat.com>
---
tools/testing/selftests/mm/run_vmtests.sh | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/mm/run_vmtests.sh
b/tools/testing/selftests/mm/run_vmtests.sh
index 471e539d82b8..f1a7ad3ec6a7 100755
--- a/tools/testing/selftests/mm/run_vmtests.sh
+++ b/tools/testing/selftests/mm/run_vmtests.sh
@@ -172,13 +172,13 @@ fi
# set proper nr_hugepages
if [ -n "$freepgs" ] && [ -n "$hpgsize_KB" ]; then
- nr_hugepgs=$(cat /proc/sys/vm/nr_hugepages)
+ nr_hugepgs_origin=$(cat /proc/sys/vm/nr_hugepages)
I'd call this "orig_nr_hugepgs".
But it's a shame that the naming is then out of sync with nr_size_hugepgs?
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 + nr_hugepgs_origin)) >
/proc/sys/vm/nr_hugepages; then
echo "Please run this test as root"
exit $ksft_skip
fi
@@ -189,6 +189,7 @@ if [ -n "$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" "$needpgs"
@@ -532,6 +533,10 @@ CATEGORY="page_frag" run_test ./test_page_frag.sh aligned
CATEGORY="page_frag" run_test ./test_page_frag.sh nonaligned
+if [ "${HAVE_HUGEPAGES}" = 1 ]; then
+ echo "$nr_hugepgs_origin" > /proc/sys/vm/nr_hugepages
+fi
FWIW, I think the tests should maybe be doing that
(save+configure+restore) themselves, like we do with THP settings through.
thp_save_settings()
thp_write_settings()
and friends.
This is not really something run_vmtests.sh should bother with.
A bigger rework, though ...
--
Cheers
David / dhildenb
