diff options
| author | Namhyung Kim <namhyung@gmail.com> | 2010-10-26 14:22:01 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-10-26 16:52:09 -0700 |
| commit | ea4525b6008fb29553306ec6719f8e6930ac9499 (patch) | |
| tree | 1d168e0a05a5f2fc962b8a6e991a21b704ad6e0b | |
| parent | 1b36ba815bd91f17e31277a44dd5c6b6a5a8d97e (diff) | |
rmap: annotate lock context change on page_[un]lock_anon_vma()
The page_lock_anon_vma() conditionally grabs RCU and anon_vma lock but
page_unlock_anon_vma() releases them unconditionally. This leads sparse
to complain about context imbalance. Annotate them.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/linux/rmap.h | 15 | ||||
| -rw-r--r-- | mm/rmap.c | 4 |
2 files changed, 17 insertions, 2 deletions
diff --git a/include/linux/rmap.h b/include/linux/rmap.h index 5c98df68a953..07ea89c16761 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -230,7 +230,20 @@ int try_to_munlock(struct page *); /* * Called by memory-failure.c to kill processes. */ -struct anon_vma *page_lock_anon_vma(struct page *page); +struct anon_vma *__page_lock_anon_vma(struct page *page); + +static inline struct anon_vma *page_lock_anon_vma(struct page *page) +{ + struct anon_vma *anon_vma; + + __cond_lock(RCU, anon_vma = __page_lock_anon_vma(page)); + + /* (void) is needed to make gcc happy */ + (void) __cond_lock(&anon_vma->root->lock, anon_vma); + + return anon_vma; +} + void page_unlock_anon_vma(struct anon_vma *anon_vma); int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma); diff --git a/mm/rmap.c b/mm/rmap.c index f5ad996a4a8f..0995a8f68866 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -314,7 +314,7 @@ void __init anon_vma_init(void) * Getting a lock on a stable anon_vma from a page off the LRU is * tricky: page_lock_anon_vma rely on RCU to guard against the races. */ -struct anon_vma *page_lock_anon_vma(struct page *page) +struct anon_vma *__page_lock_anon_vma(struct page *page) { struct anon_vma *anon_vma, *root_anon_vma; unsigned long anon_mapping; @@ -348,6 +348,8 @@ out: } void page_unlock_anon_vma(struct anon_vma *anon_vma) + __releases(&anon_vma->root->lock) + __releases(RCU) { anon_vma_unlock(anon_vma); rcu_read_unlock(); |