Re: Linux 2.5.3-pre1-aia1

Jens Axboe (axboe@suse.de)
Tue, 22 Jan 2002 09:16:53 +0100


On Mon, Jan 21 2002, Andre Hedrick wrote:
> > On Mon, Jan 21, 2002 at 03:53:20PM -0800, Andre Hedrick wrote:
> > > On Mon, 21 Jan 2002, Vojtech Pavlik wrote:
> > > Okay if the execution of the command block is ATOMIC, and we want to stop
> > > an ATOMIC operation to go alter buffers?
> >
> > YES! I think you got it! Because atomic here doesn't mean 'do it all as
> > soon as possible with no delay', but 'do nothing else on the ATA bus
> > inbetween'.
>
> In order to do this you can not issue a sector request larger than an
> addressable buffer, since the request walking of the rq->buffer is not
> allowed.

It's not that it's not allowed, it's that it doesn't work the way you
want it. ->buffer is just the first segment, which is 8 sectors max,
that much is correct. But nothing prevents your from ending the front
of the request and continuing and the drive will never know. Just see
task_mulin_intr.

-- 
Jens Axboe

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