Messages in this thread | | | Date | Fri, 4 Feb 2011 11:28:34 +0800 | From | Yong Zhang <> | Subject | Re: [PATCH 1/4] lockdep, timer: Fix del_timer_sync() annotation |
| |
On Thu, Feb 03, 2011 at 03:09:41PM +0100, Peter Zijlstra wrote: > Calling local_bh_enable() will want to actually start processing > softirqs, which isn't a good idea since this can get called with IRQs > disabled. > > Cure this by using _local_bh_enable() which doesn't start processing > softirqs, and use raw_local_irq_save() to avoid any softirqs from > happending without letting lockdep think IRQs are in fact disabled. > > Reported-by: Nick Bowler <nbowler@elliptictech.com> > Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> > LKML-Reference: <new-submission> > --- > kernel/timer.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > Index: linux-2.6/kernel/timer.c > =================================================================== > --- linux-2.6.orig/kernel/timer.c > +++ linux-2.6/kernel/timer.c > @@ -969,10 +969,14 @@ EXPORT_SYMBOL(try_to_del_timer_sync); > int del_timer_sync(struct timer_list *timer) > { > #ifdef CONFIG_LOCKDEP > + unsigned long flags; > + > + raw_local_irq_save(flags); > local_bh_disable(); > lock_map_acquire(&timer->lockdep_map); > lock_map_release(&timer->lockdep_map); > - local_bh_enable(); > + _local_bh_enable(); > + raw_local_irq_restore(flags);
This is more cheap than what I have done ;) I think it will cure the issue reported by Nick. Thanks you anyway.
Reviewed-by: Yong Zhang <yong.zhang0@gmail.com>
| |