Re: [PATCH] mm: vmscan: correct nr_reclaimed for THP

[William Kucharski]

> On May 9, 2019, at 9:03 PM, Huang, Ying <ying.huang@xxxxxxxxx> wrote:
> 
> Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx> writes:
> 
>> On 5/9/19 7:12 PM, Huang, Ying wrote:
>>> 
>>> How about to change this to
>>> 
>>> 
>>>         nr_reclaimed += hpage_nr_pages(page);
>> 
>> Either is fine to me. Is this faster than "1 << compound_order(page)"?
> 
> I think the readability is a little better.  And this will become
> 
>        nr_reclaimed += 1
> 
> if CONFIG_TRANSPARENT_HUAGEPAGE is disabled.

I find this more legible and self documenting, and it avoids the bit shift
operation completely on the majority of systems where THP is not configured.