diff options
| author | Andrew Morton <akpm@osdl.org> | 2004-06-23 18:55:44 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2004-06-23 18:55:44 -0700 |
| commit | 6a948bc8ac0d7b3c4bf1a46838fb3786ecffbd93 (patch) | |
| tree | 77b1a49078e399ce48764873e47a7a06a96a7e7a | |
| parent | 26b193e6bf56a27bc9ffe759f1c3b384c309a0a6 (diff) | |
[PATCH] nr_pagecache can go negative
We use per-cpu counters for the system-wide pagecache accounting. The
counters spill into the global nr_pagecache atomic_t when they underflow or
overflow.
Hence it is possible, under weird circumstances, for nr_pagecache to go
negative. Anton says he has hit this.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | include/linux/pagemap.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 427b696f484b..4da205f3cb26 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -8,6 +8,7 @@ #include <linux/fs.h> #include <linux/list.h> #include <linux/highmem.h> +#include <linux/compiler.h> #include <asm/uaccess.h> #include <linux/gfp.h> @@ -136,7 +137,10 @@ static inline void pagecache_acct(int count) static inline unsigned long get_page_cache_size(void) { - return atomic_read(&nr_pagecache); + int ret = atomic_read(&nr_pagecache); + if (unlikely(ret < 0)) + ret = 0; + return ret; } static inline pgoff_t linear_page_index(struct vm_area_struct *vma, |