In cgroup v2, memory and hugetlb usage reparenting is asynchronous. This
can cause test flakiness when immediately asserting usage after deleting a
child cgroup. To address this, add a helper function
`assert_with_retry()` that checks usage values with a timeout-based retry.
This improves test stability without relying on fixed sleep delays.
Also bump up the tolerance size to 7MB.
To avoid False Positives:
...
# Assert memory charged correctly for child only use.
# actual a = 11 MB
# expected a = 0 MB
# fail
# cleanup
# [FAIL]
not ok 11 hugetlb_reparenting_test.sh -cgroup-v2 # exit=1
# 0
# SUMMARY: PASS=10 SKIP=0 FAIL=1
Link: https://lkml.kernel.org/r/20250407084201.74492-1-liwang@redhat.com
Signed-off-by: Li Wang <liwang@redhat.com>
Tested-by: Donet Tom <donettom@linux.ibm.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Currently if the filesystem for the cgroups version it wants to use is not
mounted charge_reserved_hugetlb.sh and hugetlb_reparenting_test.sh tests
will attempt to mount it on the hard coded path /dev/cgroup/memory,
deleting that directory when the test finishes. This will fail if there
is not a preexisting directory at that path, and since the directory is
deleted subsequent runs of the test will fail. Instead of relying on this
hard coded directory name use mktemp to generate a temporary directory to
use as a mountpoint, fixing both the assumption and the disruption caused
by deleting a preexisting directory.
This means that if the relevant cgroup filesystem is not already mounted
then we rely on having coreutils (which provides mktemp) installed. I
suspect that many current users are relying on having things automounted
by default, and given that the script relies on bash it's probably not an
unreasonable requirement.
Link: https://lkml.kernel.org/r/20250404-kselftest-mm-cgroup2-detection-v1-1-3dba6d32ba8c@kernel.org
Fixes: 209376ed2a ("selftests/vm: make charge_reserved_hugetlb.sh work with existing cgroup setting")
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: Aishwarya TCV <aishwarya.tcv@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "selftests/mm: Improve run_vmtests.sh", v3.
In this series, I'm trying to add 3 missing tests to vm_runtests.sh which
is used to run all the tests in mm suite. These tests weren't running by
CIs. While enabling them and through review feedback, I've fixed some
problems in tests as well. I've found more flakiness in more tests which
I'll be fixing with future patches.
hugetlb-read-hwpoison test is being added where it can only run with newly
added "-d" (destructive) flag only. Not sure why it is failing again. So
once it become stable, we can think of moving it to default set of tests
if it doesn't have any side-effect to them.
This patch (of 5):
Do not unmount the cgroup if it wasn't mounted by the test. The earlier
patch had fixed this for charge_reserved_hugetlb, but not for this test.
I'm adding fixes tag to that earlier patch.
Link: https://lkml.kernel.org/r/20240125154608.720072-1-usama.anjum@collabora.com
Link: https://lkml.kernel.org/r/20240125154608.720072-2-usama.anjum@collabora.com
Fixes: 209376ed2a ("selftests/vm: make charge_reserved_hugetlb.sh work with existing cgroup setting")
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
