Re: [lkcd-devel] [PATCH] Fix the unbalanced spinlock in timer

[Jason U. <jas...@sg...>]

On Wed, Feb 15, 2006 at 12:47:24 +0100, Takashi Iwai wrote:
> Fix the unbalanced spinlock in timer.
> 
> 
> Takashi
> 
> --- linux-2.6.15/kernel/timer.c-dist	2006-01-30 18:18:24.000000000 +0100
> +++ linux-2.6.15/kernel/timer.c	2006-01-30 18:18:58.000000000 +0100
> @@ -473,7 +473,7 @@ static inline void __run_timers(tvec_bas
>  					BUG();
>  				}
>  			}
> -			spin_lock_irq(&base->t_base.lock);
> +			spin_lock_irqsave(&base->t_base.lock, flags);
>  		}
>  	}
>  	set_running_timer(base, NULL);


I think this imbalance was deliberate cleverness.  We've already saved
flags once (at the top of the function) and they're guaranteed to be
in the same state at this point.