mm: Export nr_swap_pages
authorChris Wilson <chris@chris-wilson.co.uk>
Fri, 4 Dec 2015 15:58:53 +0000 (15:58 +0000)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Tue, 5 Jan 2016 10:02:18 +0000 (11:02 +0100)
commitfb0fec501f08a0a83af7a2b25888ec8cebab53b0
tree82f78ea91951ae741276fad297ab96ea4638a0c7
parent934acce3c069a3d8b14085957248444145d9ec1b
mm: Export nr_swap_pages

Some modules, like i915.ko, use swappable objects and may try to swap
them out under memory pressure (via the shrinker). Before doing so, they
want to check using get_nr_swap_pages() to see if any swap space is
available as otherwise they will waste time purging the object from the
device without recovering any memory for the system. This requires the
nr_swap_pages counter to be exported to the modules.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: "Goel, Akash" <akash.goel@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: linux-mm@kvack.org
Link: http://patchwork.freedesktop.org/patch/msgid/1449244734-25733-1-git-send-email-chris@chris-wilson.co.uk
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
mm/swapfile.c