Re: [LTP] [linux-next:master] [mm/migrate] b28dd7507f: ltp.move_pages04.fail

[David Hildenbrand <david@redhat.com>]

On 29.08.24 16:31, Cyril Hrubis wrote:
> Hi!
>>>>> Also I think there is a third case that we do not cover either, what
>>>>> happens when we pass an address that is not mapped at all, e.g. NULL? Do
>>>>> we get EFAULT as well?
>>>>
>>>> Yes, that's documented as EFAULT and should behave that way. I can
>>>> extend the test to handle that as well.
>>>
>>> Ideally the test should be ported to the new test API as well, but I can
>>> do that later on the top of your work.
>>
>> I tried, and it all looked easy, until I realized that these tests use a
>> share code-base:
>> 	testcases/kernel/syscalls/move_pages/move_pages_support.c
>>
>> That is also written using the old API. I assume mixing APIs might not
>> work as expected ...
> 
> The tst_resm() and tst_brkm() calls are redirected proplery in the case
> that the test runs with a new API so generally it should work fine as
> long as the cleanup callback is set to NULL for the tst_brkm(). That
> was one of the design decision we took years ago, because we knew that
> we are not going to reimplement thousands of tests instantly and that
> the old and new API would have to live alongside for a decade.

Ah, the "NULL" is the magic bit.

> 
> I glanced over the code and I do not see anything in the
> move_paves_support.c or in the kernel/lib/numa_helper.c that would break
> when executed under the new library test.

Okay, good. I can send a follow up to convert that file once the 
fix/extension was reviewed.

-- 
Cheers,

David / dhildenb