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

[Andrew Morton]

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.