Commit 4c4c402d authored by Martin Hicks's avatar Martin Hicks Committed by Linus Torvalds
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[PATCH] meminfo: add Cached underflow check 



Working on some code lately I've been getting huge values for "Cached".
The cause is that get_page_cache_size() is an approximate value, and for a
sufficiently small returned value of get_page_cache_size() the value
underflows.

Signed-off-by: default avatarMartin Hicks <mort@sgi.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 76c3073a

fs/proc/proc_misc.c

+6 −1
Original line number Diff line number Diff line
@@ -126,6 +126,7 @@ static int meminfo_read_proc(char *page, char **start, off_t off, 
	unsigned long committed;

	unsigned long allowed;

	struct vmalloc_info vmi;

	long cached;



	get_page_state(&ps);

	get_zone_counts(&active, &inactive, &free);
@@ -140,6 +141,10 @@ static int meminfo_read_proc(char *page, char **start, off_t off, 
	allowed = ((totalram_pages - hugetlb_total_pages())

		* sysctl_overcommit_ratio / 100) + total_swap_pages;



	cached = get_page_cache_size() - total_swapcache_pages - i.bufferram;

	if (cached < 0)

		cached = 0;



	get_vmalloc_info(&vmi);



	/*
@@ -172,7 +177,7 @@ static int meminfo_read_proc(char *page, char **start, off_t off, 
		K(i.totalram),

		K(i.freeram),

		K(i.bufferram),

		K(get_page_cache_size()-total_swapcache_pages-i.bufferram),

		K(cached),

		K(total_swapcache_pages),

		K(active),

		K(inactive),