Re: [PATCH] mm: gup: Re-define follow_page_mask output parameter page_mask usage

[Michal Hocko]

On Wed 13-07-16 01:03:10, Chen Gang wrote:
> On 7/12/16 05:17, Andrew Morton wrote:
> > On Sun, 10 Jul 2016 01:17:05 +0800 chengang@xxxxxxxxxxxxxxxx wrote:
> > 
> >> For a pure output parameter:
> >>
> >>  - When callee fails, the caller should not assume the output parameter
> >>    is still valid.
> >>
> >>  - And callee should not assume the pure output parameter must be
> >>    provided by caller -- caller has right to pass NULL when caller does
> >>    not care about it.
> > 
> > Sorry, I don't think this one is worth merging really.
> > 
> 
> OK, thanks, I can understand.
> 
> It will be better if provide more details: e.g.
> 
>  - This patch is incorrect, or the comments is not correct.
> 
>  - The patch is worthless, at present.

I would say the patch is not really needed. The code you are touching
works just fine and there is no reason to touch it unless this is a part
of a larger change where future changes would be easier to
review/implement.

-- 
Michal Hocko
SUSE Labs