Re: [RFC PATCH 3/3] mm, fault_around: do not take a reference to a locked page

[Kirill A. Shutemov]

On Tue, Nov 20, 2018 at 02:43:23PM +0100, Michal Hocko wrote:
> From: Michal Hocko <mhocko@xxxxxxxx>
> 
> filemap_map_pages takes a speculative reference to each page in the
> range before it tries to lock that page. While this is correct it
> also can influence page migration which will bail out when seeing
> an elevated reference count. The faultaround code would bail on
> seeing a locked page so we can pro-actively check the PageLocked
> bit before page_cache_get_speculative and prevent from pointless
> reference count churn.

Looks fine to me.

But please drop a line of comment in the code. As is it might be confusing
for a reader.

-- 
 Kirill A. Shutemov