[PATCH v6, part3 15/16] mm: report available pages as "MemTotal" for each NUMA node

From: Jiang Liu
Date: Sat May 11 2013 - 13:42:32 EST


As reported by https://bugzilla.kernel.org/show_bug.cgi?id=53501,
"MemTotal" from /proc/meminfo means memory pages managed by the buddy
system (managed_pages), but "MemTotal" from /sys/.../node/nodex/meminfo
means phsical pages present (present_pages) within the NUMA node.
There's a difference between managed_pages and present_pages due to
bootmem allocator and reserved pages.

And Documentation/filesystems/proc.txt says
MemTotal: Total usable ram (i.e. physical ram minus a few reserved
bits and the kernel binary code)

So change /sys/.../node/nodex/meminfo to report available pages within
the node as "MemTotal".

Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
Reported-by: sworddragon2@xxxxxxx
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
mm/page_alloc.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 56b0097..e7a517d 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2924,9 +2924,13 @@ EXPORT_SYMBOL(si_meminfo);
#ifdef CONFIG_NUMA
void si_meminfo_node(struct sysinfo *val, int nid)
{
+ int zone_type; /* needs to be signed */
+ unsigned long managed_pages = 0;
pg_data_t *pgdat = NODE_DATA(nid);

- val->totalram = pgdat->node_present_pages;
+ 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->freeram = node_page_state(nid, NR_FREE_PAGES);
#ifdef CONFIG_HIGHMEM
val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].managed_pages;
--
1.8.1.2

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