[PATCH 1/7] mm: fix return type for functions nr_free_*_pages

From: Zhang Yanfei
Date: Wed Feb 06 2013 - 00:17:13 EST


Currently, the amount of RAM that functions nr_free_*_pages return
is held in unsigned int. But in machines with big memory (exceeding
16TB), the amount may be incorrect because of overflow, so fix it.

Signed-off-by: Zhang Yanfei <zhangyanfei@xxxxxxxxxxxxxx>
---
include/linux/swap.h | 4 ++--
mm/page_alloc.c | 8 ++++----
2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 68df9c1..c238323 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -216,8 +216,8 @@ struct swap_list_t {
extern unsigned long totalram_pages;
extern unsigned long totalreserve_pages;
extern unsigned long dirty_balance_reserve;
-extern unsigned int nr_free_buffer_pages(void);
-extern unsigned int nr_free_pagecache_pages(void);
+extern unsigned long nr_free_buffer_pages(void);
+extern unsigned long nr_free_pagecache_pages(void);

/* Definition of global_page_state not available yet */
#define nr_free_pages() global_page_state(NR_FREE_PAGES)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index df2022f..4acf733 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2785,13 +2785,13 @@ void free_pages_exact(void *virt, size_t size)
}
EXPORT_SYMBOL(free_pages_exact);

-static unsigned int nr_free_zone_pages(int offset)
+static unsigned long nr_free_zone_pages(int offset)
{
struct zoneref *z;
struct zone *zone;

/* Just pick one node, since fallback list is circular */
- unsigned int sum = 0;
+ unsigned long sum = 0;

struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);

@@ -2808,7 +2808,7 @@ static unsigned int nr_free_zone_pages(int offset)
/*
* Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
*/
-unsigned int nr_free_buffer_pages(void)
+unsigned long nr_free_buffer_pages(void)
{
return nr_free_zone_pages(gfp_zone(GFP_USER));
}
@@ -2817,7 +2817,7 @@ EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
/*
* Amount of free RAM allocatable within all zones
*/
-unsigned int nr_free_pagecache_pages(void)
+unsigned long nr_free_pagecache_pages(void)
{
return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
}
--
1.7.1

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