Re: [PATCH v3 3/3] kselftest: mm: introduce size_to_shift() helper

[David Hildenbrand (Arm)]

On 9/14/26 16:06, Yeoreum Yun wrote:
> On Mon, Sep 14, 2026 at 04:01:02PM +0200, David Hildenbrand (Arm) wrote:
>> On 9/14/26 09:30, Yeoreum Yun wrote:
>>> Introduce size_to_shift() for future users that need to
>>> obtain shift of a huge-page which is other than pmd_psize().
>>>
>>> Suggested-by: David Hildenbrand (Arm) <david@xxxxxxxxxx>
>>> Signed-off-by: Yeoreum Yun <yeoreum.yun@xxxxxxx>
>>> ---
>>>  tools/testing/selftests/mm/vm_util.c | 10 +++++++++-
>>>  tools/testing/selftests/mm/vm_util.h |  1 +
>>>  2 files changed, 10 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c
>>> index fd1432dc6152..1fef1266429f 100644
>>> --- a/tools/testing/selftests/mm/vm_util.c
>>> +++ b/tools/testing/selftests/mm/vm_util.c
>>> @@ -157,6 +157,14 @@ bool check_for_pattern(FILE *fp, const char *pattern, char *buf, size_t len)
>>>  	return false;
>>>  }
>>>  
>>> +uint64_t size_to_shift(uint64_t size)
>>> +{
>>> +	if (__builtin_popcountll(size) != 1)
>>> +		return 0;
>>> +
>>> +	return ffsl(size) - 1;
>>> +}
>>
>> Could likely just be an inline helper?
> 
> Okay. If there is no comments on today, I'll post tomorrow with this.
> 

No need to rush, leave some more days for people to catch up.

-- 
Cheers,

David