Re: [PATCH RFC v2 5/7] mm: selftests: Add shmem memory failure test

Baolin Wang
2026-03-24T12:36:47Z

On 3/24/26 8:43 AM, Lisa Wang wrote:
> On Sat, Mar 21, 2026 at 02:30:04PM +0800, Baolin Wang wrote:
>>
>>
>> On 3/20/26 7:30 AM, Lisa Wang wrote:
>>> Add a shmem memory failure selftest to test the shmem memory failure is
>>> correct after modifying shmem return value.
>>>
>>> Test that
>>> + madvise() call returns 0 at the first time
>>> + trigger a SIGBUS when the poisoned shmem page is fault-in again.
>>>
>>> Signed-off-by: Lisa Wang <wyihan@google.com>
>>> ---
>>
>> Why not move the shmem memory failure test into memory-failure.c?
>
> Do you mean let memory-failure.c kernel code check by itself?
> The reason I write the selftest instead of combining in memory-failure.c
> is because
> + do not need extra checking code in kernel code
> + make it easier to trace the entire execution flow, starting from the
> madvise() down through shmem_error_remove_folio() and into the
> truncate_error_folio() logic.
>
> Pleas let me know if I've missed something. Thanks!

That's not quite what I meant. I mean, since there is already a
memory-failure.c in mm selftests (see [1]), I think we should move the
shmem memory failure test cases into that file.

[1]