On Tue, 25 Jan 2011 13:53:45 +0900 Toshiyuki Okajima [off-list ref] wrote:

quoted

It should be fairly simple to reproduce this hang with the userspace
test harness (http://userweb.kernel.org/~akpm/stuff/rtth.tar.gz) and to
then demonstrate that the fix fixes it.

If you have time, could you please do that and then send the rtth
updates to me?

I add regression2_test for this bug into your testset (rtth.tar.gz).
This is originated from regression1_test.

Thanks.  I applied your
radix_tree-radix_tree_gang_lookup_tag_slot-may-not-return-forever.patch
to rtth's radix-tree.c (it was needed!) and refreshed
http://userweb.kernel.org/~akpm/stuff/rtth.tar.gz