Revert "mm: don't reclaim inodes with many attached pages"

This reverts commit a76cf1a4 ("mm: don't reclaim inodes with many
attached pages").

This change causes serious changes to page cache and inode cache
behaviour and balance, resulting in major performance regressions when
combining worklaods such as large file copies and kernel compiles.

  https://bugzilla.kernel.org/show_bug.cgi?id=202441

This change is a hack to work around the problems introduced by changing
how agressive shrinkers are on small caches in commit 172b06c3 ("mm:
slowly shrink slabs with a relatively small number of objects").  It
creates more problems than it solves, wasn't adequately reviewed or
tested, so it needs to be reverted.

Link: http://lkml.kernel.org/r/20190130041707.27750-2-david@fromorbit.com


Fixes: a76cf1a4 ("mm: don't reclaim inodes with many attached pages")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Cc: Wolfgang Walter <linux@stwm.de>
Cc: Roman Gushchin <guro@fb.com>
Cc: Spock <dairinin@gmail.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>