[PATCH v3 10/10] selftests/mm: Ensure uffd-wp-mremap gets pages of each size

[Brendan Jackman <jackmanb@google.com>]

This test allocates a page of every available size and doesn't have any
SKIP logic if the allocation fails. So, ensure it's available and skip
the test if we can't do so.

Signed-off-by: Brendan Jackman <jackmanb@google.com>
---
 tools/testing/selftests/mm/run_vmtests.sh | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh
index 0f9fe757c3320a6551e39b6d4552fd4874b0bf43..e86ef8cb37d00e572be8cf0ea9cc8246d4eecd7e 100755
--- a/tools/testing/selftests/mm/run_vmtests.sh
+++ b/tools/testing/selftests/mm/run_vmtests.sh
@@ -309,9 +309,30 @@ CATEGORY="userfaultfd" run_test ${uffd_stress_bin} hugetlb "$half_ufd_size_MB" 3
 CATEGORY="userfaultfd" run_test ${uffd_stress_bin} hugetlb-private "$half_ufd_size_MB" 32
 CATEGORY="userfaultfd" run_test ${uffd_stress_bin} shmem 20 16
 CATEGORY="userfaultfd" run_test ${uffd_stress_bin} shmem-private 20 16
-CATEGORY="userfaultfd" run_test ./uffd-wp-mremap
+# uffd-wp-mremap requires at least one page of each size.
+have_all_size_hugepgs=true
+declare -A nr_size_hugepgs
+for f in /sys/kernel/mm/hugepages/**/nr_hugepages; do
+	old=$(cat $f)
+	nr_size_hugepgs["$f"]="$old"
+	if [ "$old" == 0 ]; then
+		echo 1 > "$f"
+	fi
+	if [ $(cat "$f") == 0 ]; then
+		have_all_size_hugepgs=false
+		break
+	fi
+done
+if $have_all_size_hugepgs; then
+	CATEGORY="userfaultfd" run_test ./uffd-wp-mremap
+else
+	echo "# SKIP ./uffd-wp-mremap"
+fi
 
 #cleanup
+for f in "${!nr_size_hugepgs[@]}"; do
+	echo "${nr_size_hugepgs["$f"]}" > "$f"
+done
 echo "$nr_hugepgs" > /proc/sys/vm/nr_hugepages
 
 CATEGORY="compaction" run_test ./compaction_test

-- 
2.48.1.711.g2feabab25a-goog