Re: [PATCH 0/3] fs, mm: get rid of PAGE_CACHE_* and page_cache_{get,release} macros

From: Kirill A. Shutemov
Date: Mon Mar 21 2016 - 12:34:31 EST

On Mon, Mar 21, 2016 at 11:25:09AM -0500, Christoph Lameter wrote:
> On Mon, 21 Mar 2016, Kirill A. Shutemov wrote:
> > PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago
> > with promise that one day it will be possible to implement page cache with
> > bigger chunks than PAGE_SIZE.
> >
> > This promise never materialized. And unlikely will.
> So we decided that we are never going to put THP pages on a LRU?

Err?.. What?

We do have anon-THP pages on LRU. My huge tmpfs patchset also put
file-THPs on LRU list.

The patchset has nothing to do with THP or them being on LRU.

> Will this actually work if we have really huge memory (100s of TB) where
> almost everything is a huge page? Guess we have to use hugetlbfs and we
> need to think about this as being exempt from paging.

Sorry, I failed to understand your message.

Look on huge tmpfs patchset. It allows both small and huge pages in page

Anyway, it's out of scope of the patchset.

Kirill A. Shutemov