Subject: Re: write cache on ATA drives
To: Jason R Thorpe <thorpej@wasabisystems.com>
From: Thor Lancelot Simon <tls@rek.tjls.com>
List: tech-kern
Date: 12/09/2002 20:36:50
On Mon, Dec 09, 2002 at 05:24:55PM -0800, Jason R Thorpe wrote:
> On Mon, Dec 09, 2002 at 08:11:32PM -0500, Thor Lancelot Simon wrote:
> 
>  > Unless someone whacked it back out of all the SCSI drivers after I put it in,
>  > yes.
> 
> That logic does NOT belong in the SCSI drivers.  It should be handled in
> the mid-layer.

When I added it, we didn't _have_ a real mid-layer.  If it's still there,
by all means, feel free to move it. :-)

On a less contentious note, what do you think about my suggestion that we
should have that logic _somewhere_ and that we should explicitly set
drives' reordering policy in order to take advantage of it?  It's a hell
of a lot better than turning on the write cache, and we don't have to make
it a persistent setting, right? (I cannot remember how that mode page 
works).

It seems like this would provide exactly what softdep wants, among other
benefits.

-- 
 Thor Lancelot Simon	                                      tls@rek.tjls.com
   But as he knew no bad language, he had called him all the names of common
 objects that he could think of, and had screamed: "You lamp!  You towel!  You
 plate!" and so on.              --Sigmund Freud