[PATCH 5.15 094/262] selftests/vm: make charge_reserved_hugetlb.sh work with existing cgroup setting

From: Greg Kroah-Hartman
Date: Mon Mar 07 2022 - 05:02:40 EST


From: Waiman Long <longman@xxxxxxxxxx>

[ Upstream commit 209376ed2a8431ccb4c40fdcef11194fc1e749b0 ]

The hugetlb cgroup reservation test charge_reserved_hugetlb.sh assume
that no cgroup filesystems are mounted before running the test. That is
not true in many cases. As a result, the test fails to run. Fix that
by querying the current cgroup mount setting and using the existing
cgroup setup instead before attempting to freshly mount a cgroup
filesystem.

Similar change is also made for hugetlb_reparenting_test.sh as well,
though it still has problem if cgroup v2 isn't used.

The patched test scripts were run on a centos 8 based system to verify
that they ran properly.

Link: https://lkml.kernel.org/r/20220106201359.1646575-1-longman@xxxxxxxxxx
Fixes: 29750f71a9b4 ("hugetlb_cgroup: add hugetlb_cgroup reservation tests")
Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
Acked-by: Mina Almasry <almasrymina@xxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
.../selftests/vm/charge_reserved_hugetlb.sh | 34 +++++++++++--------
.../selftests/vm/hugetlb_reparenting_test.sh | 21 +++++++-----
.../selftests/vm/write_hugetlb_memory.sh | 2 +-
3 files changed, 34 insertions(+), 23 deletions(-)

diff --git a/tools/testing/selftests/vm/charge_reserved_hugetlb.sh b/tools/testing/selftests/vm/charge_reserved_hugetlb.sh
index fe8fcfb334e06..a5cb4b09a46c4 100644
--- a/tools/testing/selftests/vm/charge_reserved_hugetlb.sh
+++ b/tools/testing/selftests/vm/charge_reserved_hugetlb.sh
@@ -24,19 +24,23 @@ if [[ "$1" == "-cgroup-v2" ]]; then
reservation_usage_file=rsvd.current
fi

-cgroup_path=/dev/cgroup/memory
-if [[ ! -e $cgroup_path ]]; then
- mkdir -p $cgroup_path
- if [[ $cgroup2 ]]; then
+if [[ $cgroup2 ]]; then
+ cgroup_path=$(mount -t cgroup2 | head -1 | awk -e '{print $3}')
+ if [[ -z "$cgroup_path" ]]; then
+ cgroup_path=/dev/cgroup/memory
mount -t cgroup2 none $cgroup_path
- else
+ do_umount=1
+ fi
+ echo "+hugetlb" >$cgroup_path/cgroup.subtree_control
+else
+ cgroup_path=$(mount -t cgroup | grep ",hugetlb" | awk -e '{print $3}')
+ if [[ -z "$cgroup_path" ]]; then
+ cgroup_path=/dev/cgroup/memory
mount -t cgroup memory,hugetlb $cgroup_path
+ do_umount=1
fi
fi
-
-if [[ $cgroup2 ]]; then
- echo "+hugetlb" >/dev/cgroup/memory/cgroup.subtree_control
-fi
+export cgroup_path

function cleanup() {
if [[ $cgroup2 ]]; then
@@ -108,7 +112,7 @@ function setup_cgroup() {

function wait_for_hugetlb_memory_to_get_depleted() {
local cgroup="$1"
- local path="/dev/cgroup/memory/$cgroup/hugetlb.${MB}MB.$reservation_usage_file"
+ local path="$cgroup_path/$cgroup/hugetlb.${MB}MB.$reservation_usage_file"
# Wait for hugetlbfs memory to get depleted.
while [ $(cat $path) != 0 ]; do
echo Waiting for hugetlb memory to get depleted.
@@ -121,7 +125,7 @@ function wait_for_hugetlb_memory_to_get_reserved() {
local cgroup="$1"
local size="$2"

- local path="/dev/cgroup/memory/$cgroup/hugetlb.${MB}MB.$reservation_usage_file"
+ local path="$cgroup_path/$cgroup/hugetlb.${MB}MB.$reservation_usage_file"
# Wait for hugetlbfs memory to get written.
while [ $(cat $path) != $size ]; do
echo Waiting for hugetlb memory reservation to reach size $size.
@@ -134,7 +138,7 @@ function wait_for_hugetlb_memory_to_get_written() {
local cgroup="$1"
local size="$2"

- local path="/dev/cgroup/memory/$cgroup/hugetlb.${MB}MB.$fault_usage_file"
+ local path="$cgroup_path/$cgroup/hugetlb.${MB}MB.$fault_usage_file"
# Wait for hugetlbfs memory to get written.
while [ $(cat $path) != $size ]; do
echo Waiting for hugetlb memory to reach size $size.
@@ -574,5 +578,7 @@ for populate in "" "-o"; do
done # populate
done # method

-umount $cgroup_path
-rmdir $cgroup_path
+if [[ $do_umount ]]; then
+ umount $cgroup_path
+ rmdir $cgroup_path
+fi
diff --git a/tools/testing/selftests/vm/hugetlb_reparenting_test.sh b/tools/testing/selftests/vm/hugetlb_reparenting_test.sh
index 4a9a3afe9fd4d..bf2d2a684edfd 100644
--- a/tools/testing/selftests/vm/hugetlb_reparenting_test.sh
+++ b/tools/testing/selftests/vm/hugetlb_reparenting_test.sh
@@ -18,19 +18,24 @@ if [[ "$1" == "-cgroup-v2" ]]; then
usage_file=current
fi

-CGROUP_ROOT='/dev/cgroup/memory'
-MNT='/mnt/huge/'

-if [[ ! -e $CGROUP_ROOT ]]; then
- mkdir -p $CGROUP_ROOT
- if [[ $cgroup2 ]]; then
+if [[ $cgroup2 ]]; then
+ CGROUP_ROOT=$(mount -t cgroup2 | head -1 | awk -e '{print $3}')
+ if [[ -z "$CGROUP_ROOT" ]]; then
+ CGROUP_ROOT=/dev/cgroup/memory
mount -t cgroup2 none $CGROUP_ROOT
- sleep 1
- echo "+hugetlb +memory" >$CGROUP_ROOT/cgroup.subtree_control
- else
+ do_umount=1
+ fi
+ echo "+hugetlb +memory" >$CGROUP_ROOT/cgroup.subtree_control
+else
+ CGROUP_ROOT=$(mount -t cgroup | grep ",hugetlb" | awk -e '{print $3}')
+ if [[ -z "$CGROUP_ROOT" ]]; then
+ CGROUP_ROOT=/dev/cgroup/memory
mount -t cgroup memory,hugetlb $CGROUP_ROOT
+ do_umount=1
fi
fi
+MNT='/mnt/huge/'

function get_machine_hugepage_size() {
hpz=$(grep -i hugepagesize /proc/meminfo)
diff --git a/tools/testing/selftests/vm/write_hugetlb_memory.sh b/tools/testing/selftests/vm/write_hugetlb_memory.sh
index d3d0d108924d4..70a02301f4c27 100644
--- a/tools/testing/selftests/vm/write_hugetlb_memory.sh
+++ b/tools/testing/selftests/vm/write_hugetlb_memory.sh
@@ -14,7 +14,7 @@ want_sleep=$8
reserve=$9

echo "Putting task in cgroup '$cgroup'"
-echo $$ > /dev/cgroup/memory/"$cgroup"/cgroup.procs
+echo $$ > ${cgroup_path:-/dev/cgroup/memory}/"$cgroup"/cgroup.procs

echo "Method is $method"

--
2.34.1