Re: [PATCH] selftests/vm: Make charge_reserved_hugetlb.sh work with existing cgroup setting

[Mina Almasry]

On Thu, Jan 6, 2022 at 12:14 PM Waiman Long <longman@xxxxxxxxxx> wrote:
>
> 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.
>
> Fixes: 29750f71a9b4 ("hugetlb_cgroup: add hugetlb_cgroup reservation tests")
> Signed-off-by: Waiman Long <longman@xxxxxxxxxx>

Thank you very much.

Acked-by: Mina Almasry <almasrymina@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(-)
>  mode change 100644 => 100755 tools/testing/selftests/vm/charge_reserved_hugetlb.sh
>  mode change 100644 => 100755 tools/testing/selftests/vm/hugetlb_reparenting_test.sh
>  mode change 100644 => 100755 tools/testing/selftests/vm/write_hugetlb_memory.sh
>
> diff --git a/tools/testing/selftests/vm/charge_reserved_hugetlb.sh b/tools/testing/selftests/vm/charge_reserved_hugetlb.sh
> old mode 100644
> new mode 100755
> index fe8fcfb334e0..a5cb4b09a46c
> --- 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
> old mode 100644
> new mode 100755
> index 4a9a3afe9fd4..bf2d2a684edf
> --- 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
> old mode 100644
> new mode 100755
> index d3d0d108924d..70a02301f4c2
> --- 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"
>
> --
> 2.27.0
>