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

From: Roman Gushchin
Date: Mon Mar 05 2018 - 08:38:39 EST


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