On Mon, Nov 14, 2011 at 07:10:28PM +0800, Jan Kara wrote:
> 
>   Hello,
> 
>   these two patches aim at making task waiting in balance_dirty_pages()
> killable.  This is desirable because otherwise if filesystem stops accepting
> writes (e.g. if device has been removed or other serious error condidion) we
> have a task stuck in D state forever.

Agreed totally. I myself has run into such conditions and get very
annoyed not being able to kill the hard throttled tasks -- they just
stuck there for ever if the error condition does not change.

>   I'm not sure who should merge these two patches... Al, Fengguang?

I'd like to do it -- otherwise there will obviously be merge conflicts.

Actually I also queued a patch to do this (attached). Your patches do
better on TASK_KILLABLE and the use of signal_pending() in write
routines, while mine goes further to add the break to various
filesystems.  How about combining them together?

Thanks,
Fengguang