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| author | Shaohua Li <shaohua.li@intel.com> | 2011-05-24 17:13:35 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-05-25 08:39:54 -0700 |
| commit | c84598bbfa756b7d042da31aa4e198ae866a6c7d (patch) | |
| tree | 9287d1dcfd313193b944f3dc49a6519a40a7ee4f /include/linux/percpu_counter.h | |
| parent | 3c8f370ded3483b27f1218ff0051fcf0c7a2facd (diff) | |
| download | lwn-c84598bbfa756b7d042da31aa4e198ae866a6c7d.tar.gz lwn-c84598bbfa756b7d042da31aa4e198ae866a6c7d.zip | |
percpu_counter: change return value and add comments
The percpu_counter_*_positive() API in UP case doesn't check if return
value is positive. Add comments to explain why we don't. Also if count <
0, returns 0 instead of 1 for *read_positive().
[akpm@linux-foundation.org: tweak comment]
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/percpu_counter.h')
| -rw-r--r-- | include/linux/percpu_counter.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/include/linux/percpu_counter.h b/include/linux/percpu_counter.h index 46f6ba56fa91..5edc9014263a 100644 --- a/include/linux/percpu_counter.h +++ b/include/linux/percpu_counter.h @@ -75,7 +75,7 @@ static inline s64 percpu_counter_read_positive(struct percpu_counter *fbc) barrier(); /* Prevent reloads of fbc->count */ if (ret >= 0) return ret; - return 1; + return 0; } static inline int percpu_counter_initialized(struct percpu_counter *fbc) @@ -133,6 +133,10 @@ static inline s64 percpu_counter_read(struct percpu_counter *fbc) return fbc->count; } +/* + * percpu_counter is intended to track positive numbers. In the UP case the + * number should never be negative. + */ static inline s64 percpu_counter_read_positive(struct percpu_counter *fbc) { return fbc->count; |