path: root/mm
diff options
authorRafael Aquini <>2014-08-06 16:06:38 -0700
committerLinus Torvalds <>2014-08-06 18:01:19 -0700
commitcc7452b6dca384400960d40090a98d0eb920ab22 (patch)
treea87ea435e22a09630d1d74c30052744414359095 /mm
parent82f71ae4a2b829a25971bdf54b4d0d3d69d3c8b7 (diff)
mm: export NR_SHMEM via sysinfo(2) / si_meminfo() interfaces
Historically, we exported shared pages to userspace via sysinfo(2) sharedram and /proc/meminfo's "MemShared" fields. With the advent of tmpfs, from kernel v2.4 onward, that old way for accounting shared mem was deemed inaccurate and we started to export a hard-coded 0 for sysinfo.sharedram. Later on, during the 2.6 timeframe, "MemShared" got re-introduced to /proc/meminfo re-branded as "Shmem", but we're still reporting sysinfo.sharedmem as that old hard-coded zero, which makes the "shared memory" report inconsistent across interfaces. This patch leverages the addition of explicit accounting for pages used by shmem/tmpfs -- "4b02108 mm: oom analysis: add shmem vmstat" -- in order to make the users of sysinfo(2) and si_meminfo*() friends aware of that vmstat entry and make them report it consistently across the interfaces, as well to make sysinfo(2) returned data consistent with our current API documentation states. Signed-off-by: Rafael Aquini <> Acked-by: Rik van Riel <> Cc: Mel Gorman <> Cc: Johannes Weiner <> Cc: KOSAKI Motohiro <> Cc: Hugh Dickins <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
Diffstat (limited to 'mm')
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c1c6cb78e5ca..0987ac9f0a4e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3047,7 +3047,7 @@ static inline void show_node(struct zone *zone)
void si_meminfo(struct sysinfo *val)
val->totalram = totalram_pages;
- val->sharedram = 0;
+ val->sharedram = global_page_state(NR_SHMEM);
val->freeram = global_page_state(NR_FREE_PAGES);
val->bufferram = nr_blockdev_pages();
val->totalhigh = totalhigh_pages;
@@ -3067,6 +3067,7 @@ void si_meminfo_node(struct sysinfo *val, int nid)
for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
managed_pages += pgdat->node_zones[zone_type].managed_pages;
val->totalram = managed_pages;
+ val->sharedram = node_page_state(nid, NR_SHMEM);
val->freeram = node_page_state(nid, NR_FREE_PAGES);
val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].managed_pages;