Re: [PATCH] selftests/mm: skip split_huge_page_test without the split_huge_pages file

[David Hildenbrand (Arm)]

On 11/5/26 16:19, Zi Yan wrote:
> On 4 Nov 2026, at 22:02, Sasha Levin wrote:
> 
>> Every case in split_huge_page_test goes through
>> /sys/kernel/debug/split_huge_pages. When that file does not exist,
>> because debugfs is not mounted or the kernel has no CONFIG_DEBUG_FS, the
>> first write bails out of the whole test and it is reported as a failure:
>>
>>   Bail out! write_file(/sys/kernel/debug/split_huge_pages): No such file or directory
>>
>> Skip the test in that case.
>>
>> Fixes: fa6c02315f74 ("mm: huge_memory: a new debugfs interface for splitting THP tests")
>> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
>> ---
>> Found with KernelCI's NVIDIA lab, which runs the tests in a chroot
>> without debugfs. Tested on an AMD EPYC 9655P with KernelCI's x86_64
>> build of next-20261104: without debugfs the test now skips, and with
>> debugfs mounted it still passes all 62 cases.
>>
>>  tools/testing/selftests/mm/split_huge_page_test.c | 3 +++
>>  1 file changed, 3 insertions(+)
>>
> 
> Thanks. But I do think we need a way of specifying the necessary
> Kconfig options for selftests. Oh, we do have one:
> https://elixir.bootlin.com/linux/v7.3.1/source/tools/testing/selftests/mm/config. Can you add CONFIG_DEBUG_FS=y to it while at it?

Just what I was thinking.

-- 
Cheers,

David