Re: [PATCH] mm,thp: stop leaking unreleased file pages

[Matthew Wilcox]

On Wed, May 27, 2020 at 02:28:10PM -0700, Hugh Dickins wrote:
> Saying "source inspection" reminds me: there is another funny in there,
> but I don't think it matters very much in practice, and might need
> rather a lot of testing to justify any particular patch: where
> page_cache_sync_readahead() asks for PAGE_SIZE pages!
> 
> "end - index" seems a more reasonable number to me: but then we
> might find that reading ahead into the next huge extent had actually
> been a useful optimization (and those readahead functions impose
> their own caps, so PAGE_SIZE shouldn't work out too outrageously).

That readahead was only added in 99cb0dbd47a15d395bf3faa78dc122bc5efe3fc0
so it probably hasn't really been performance tested yet.