Re: [PATCH 0/3] fs, mm: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
From: Kirill A. Shutemov <hidden>
Date: 2016-03-21 17:06:55
Also in:
linux-fsdevel, lkml
On Mon, Mar 21, 2016 at 11:59:25AM -0500, Christoph Lameter wrote:
On Mon, 21 Mar 2016, Kirill A. Shutemov wrote:quoted
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.
One entry on LRU per huge page.
quoted
quoted
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.
We do have two page sizes in the page cache. It's the only option to get transparent huge pages transparent. We have 512 (on x86-64) entries on radix-tree per huge page, but we can opt to Matthew's multi-order entries later. See e61452365372 "radix_tree: add support for multi-order entries". -- Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>