[PATCH 2/3] mm: treat indirectly reclaimable memory as available in MemAvailable

[Roman Gushchin]

This patch adjusts /proc/meminfo MemAvailable calculation
by adding the amount of indirectly reclaimable memory
(rounded to the PAGE_SIZE).

Signed-off-by: Roman Gushchin <guro@xxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: linux-fsdevel@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Cc: kernel-team@xxxxxx
---
 mm/page_alloc.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 2836bc9e0999..2247cda9e94e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4695,6 +4695,13 @@ long si_mem_available(void)
 		     min(global_node_page_state(NR_SLAB_RECLAIMABLE) / 2,
 			 wmark_low);
 
+	/*
+	 * Part of the kernel memory, which can be released under memory
+	 * pressure.
+	 */
+	available += global_node_page_state(NR_INDIRECTLY_RECLAIMABLE_BYTES) >>
+		PAGE_SHIFT;
+
 	if (available < 0)
 		available = 0;
 	return available;
-- 
2.14.3