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

From: Christoph Lameter
Date: Mon Mar 21 2016 - 12:59:30 EST


On Mon, 21 Mar 2016, Kirill A. Shutemov wrote:

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

So they are on the LRU as 4k units? Tried to look it up.

> > 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
> cache.

Thus my wonder about this patchset. It seems then that the huge pages are
treated as 4k pages? Otherwise we would have two sizes for pages in the
page cache. Sorry I did not follow that too closely. Will try finding that
patchset.