mm: remove useless rcu lock-unlock from mapping_tagged()

radix_tree_tagged() is lockless - it reads from a member of the raid-tree
root node.  It does not require any protection.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Konstantin Khlebnikov 2011-07-25 17:12:31 -07:00 committed by Linus Torvalds
parent 76d3fbf8fb
commit 72c4783210
1 changed files with 1 additions and 5 deletions

View File

@ -1405,10 +1405,6 @@ EXPORT_SYMBOL(test_set_page_writeback);
*/
int mapping_tagged(struct address_space *mapping, int tag)
{
int ret;
rcu_read_lock();
ret = radix_tree_tagged(&mapping->page_tree, tag);
rcu_read_unlock();
return ret;
return radix_tree_tagged(&mapping->page_tree, tag);
}
EXPORT_SYMBOL(mapping_tagged);