Re: 2.6.20-rc3-mm1 - git-block.patch causes hard lockups

[Valdis.Kletnieks@vt.edu]

On Mon, 08 Jan 2007 09:55:24 +0100, Jens Axboe said:
> On Sat, Jan 06 2007, Valdis.Kletnieks@vt.edu wrote:
> > On Thu, 04 Jan 2007 22:02:00 PST, Andrew Morton said:
> > 
> > > 	ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.20-rc
3/2.6.20-rc3-mm1/
> > 
> > With git-block.patch applied, my system locks up *hard* at system
> > shutdown time - even alt-sysrq doesn't do anything.  Need to do the
> > "power button for 5" stunt to get the system back.
> 
> Does this change anything?
> 
> diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
> index ec40e44..bae57e0 100644
> --- a/block/ll_rw_blk.c
> +++ b/block/ll_rw_blk.c
> @@ -1542,7 +1542,7 @@ static inline void queue_sync_plugs(request_queue_t *q)
>  	 * If the current process is plugged and has barriers submitted,
>  	 * we will livelock if we don't unplug first.
>  	 */
> -	blk_unplug_current();
> +	blk_replug_current_nested();
>  
>  	synchronize_qrcu(&q->qrcu);
>  }

Nope, still hangs exactly the same way.  Maybe I need to get the watchdog
timer stuff working, and see if that can kick the system in a way that
produces a backtrace....

Attachment: pgpLslFkMXIN2.pgp
Description: PGP signature