Re: [PATCH v3 04/13] selftest/mm: fix cgroup task placement and drop memory.current checks in hugetlb_reparenting_test.sh

Sayali Patil
2026-04-03T19:59:50Z

On 01/04/26 19:38, David Hildenbrand (Arm) wrote:
> On 3/27/26 08:15, Sayali Patil wrote:
>> Launch write_to_hugetlbfs as a separate process and move only its PID
>> into the target cgroup before waiting for completion. This avoids moving
>> the test shell itself, prevents unintended charging to the shell, and
>> ensures hugetlb and memcg accounting is attributed only to the intended
>> workload.
>>
>> Add a short delay before the hugetlb allocation to avoid a race where
>> memory may be charged before the task migration takes effect, which
>> can lead to incorrect accounting and intermittent test failures.
>
> Isn't there still a chance for a race, for example, when running in a VM?
>
Yes, there is still a small race window in the current approach.

I am looking into making this more reliable with a deterministic
synchronization mechanism to avoid such timing dependencies.

I will send a v4 with this improvement.

Thanks,
Sayali