From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 27 Nov 2008 19:39:26 +0800 From: Wu Fengguang Subject: Re: [PATCH] radix-tree: document wrap-around issue of radix_tree_next_hole() Message-ID: <20081127113926.GA28636@localhost> References: <20081123105155.GA14524@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org Return-Path: To: Jiri Kosina Cc: Trivial Patch Monkey , Nick Piggin , linux-mm List-ID: On Thu, Nov 27, 2008 at 12:38:06PM +0200, Jiri Kosina wrote: > On Sun, 23 Nov 2008, Wu Fengguang wrote: > > > And some 80-line cleanups. > > > > Signed-off-by: Wu Fengguang > > --- > > lib/radix-tree.c | 11 ++++++----- > > 1 file changed, 6 insertions(+), 5 deletions(-) > > > > --- linux-2.6.orig/lib/radix-tree.c > > +++ linux-2.6/lib/radix-tree.c > > @@ -640,13 +640,14 @@ EXPORT_SYMBOL(radix_tree_tag_get); > > * > > * Returns: the index of the hole if found, otherwise returns an index > > * outside of the set specified (in which case 'return - index >= max_scan' > > - * will be true). > > + * will be true). In rare cases of index wrap-around, 0 will be returned. > > * > > * radix_tree_next_hole may be called under rcu_read_lock. However, like > > - * radix_tree_gang_lookup, this will not atomically search a snapshot of the > > - * tree at a single point in time. For example, if a hole is created at index > > - * 5, then subsequently a hole is created at index 10, radix_tree_next_hole > > - * covering both indexes may return 10 if called under rcu_read_lock. > > + * radix_tree_gang_lookup, this will not atomically search a snapshot of > > + * the tree at a single point in time. For example, if a hole is created > > + * at index 5, then subsequently a hole is created at index 10, > > + * radix_tree_next_hole covering both indexes may return 10 if called > > + * under rcu_read_lock. > > */ > > unsigned long radix_tree_next_hole(struct radix_tree_root *root, > > unsigned long index, unsigned long max_scan) > > > > I don't see this applied in any of the publically visible trees, so I have > taken this into -trivial. Please let me know if it has been through any > other channel already. OK, thank you. Fengguang -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org