[PATCH 52/53] selftests/mm: run_vmtests.sh: free memory if available memory is low

[Mike Rapoport]

From: "Mike Rapoport (Microsoft)" <rppt@xxxxxxxxxx>

Currently when running THP and HugeTLB tests, if HAVE_HUGEPAGES is set
run_test() drops caches, compacts memory and runs the test. But if
HAVE_HUGEPAGES is not set it skips the tests entirely, even if THP tests
have nothing to do with HAVE_HUGEPAGES.

Replace the check if HAVE_HUGEPAGES is set with a check of how much memory
is available. If there is less than 256 MB of available memory, drop caches
and run compaction and then continue to run a test regardless of
HAVE_HUGEPAGES value.

Signed-off-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
---
 tools/testing/selftests/mm/run_vmtests.sh | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh
index b9e520194634..b42d19036182 100755
--- a/tools/testing/selftests/mm/run_vmtests.sh
+++ b/tools/testing/selftests/mm/run_vmtests.sh
@@ -99,6 +99,9 @@ EOF
 	exit 0
 }
 
+mem_available_kb=$(awk '/MemAvailable/ {print $2}' /proc/meminfo)
+mem_available_Mb=$((mem_available_kb / 1024))
+
 RUN_ALL=false
 RUN_DESTRUCTIVE=false
 TAP_PREFIX="# "
@@ -239,15 +242,12 @@ run_test() {
 		# On memory constrainted systems some tests can fail to allocate hugepages.
 		# perform some cleanup before the test for a higher success rate.
 		if [ ${CATEGORY} == "thp" -o ${CATEGORY} == "hugetlb" ]; then
-			if [ "${HAVE_HUGEPAGES}" = "1" ]; then
-				echo 3 > /proc/sys/vm/drop_caches
-				sleep 2
-				echo 1 > /proc/sys/vm/compact_memory
-				sleep 2
-			else
-				echo "hugepages not supported" | tap_prefix
-				skip=1
-			fi
+		    if (( $mem_available_Mb < 256 )); then
+			echo 3 > /proc/sys/vm/drop_caches
+			sleep 2
+			echo 1 > /proc/sys/vm/compact_memory
+			sleep 2
+		    fi
 		fi
 
 		local test=$(pretty_name "$*")
-- 
2.53.0