On Fri, Jul 3, 2009 at 12:07 AM, Li Zefan<lizf at cn.fujitsu.com> wrote: > >> + write_lock_irq(&css_set_lock); > > can be read_lock(&css_set_lock); I simplified the whole thing by removing the task_lock(current) and expanding the RCU section to cover the point where we read current->cgroups too. Paul