You can drop this patch.
This turned out to be a race in xpmem. It "appeared" as if it were a
race in get_task_mm, but it really is not. The current->mm field is
cleared under the task_lock and the task_lock is grabbed by get_task_mm.
I have been testing you v15 version without this patch and not
encountere the problem again (now that I fixed my xpmem race).
Thanks,
Robin
On Wed, May 07, 2008 at 04:35:52PM +0200, Andrea Arcangeli wrote: