Re: block devices don't work without plugging in 2.4.3

[Jens Axboe <axboe@suse.de>]

On Thu, Apr 19 2001, Peter T. Breuer wrote:
> "A month of sundays ago Jens Axboe wrote:"
> > On Thu, Apr 19 2001, Peter T. Breuer wrote:
> > > So the consensus is that I should enable plugging while the plugging
> > > function is still here and do nothing when it goes? I must say I don't
> > > think it should really "go", since that means I have to add a no-op
> > > macro to replace it, and I don't like #ifdefs. 
> > 
> > The moral would be that you should never do anything. You didn't enable
> > plugging with blk_queue_pluggable, only disabled it by using a noop
> > plug.
> 
> I was thinking about what has to be done to allow my code to compile in
> older kernels. I _believe_ (I may be mistaken) that I had to _explicitly_
> disable plugging at some stage. Probably in 2.2. and possibly in 2.4.0.
> 
> On that basis, I do need a plug_fn and a blk_queue_pluggable for
> compilation against those kernels, and these should both be macro'ed to
> oblivion in the newest kernels. No? 

Examine _why_ you don't want plugging. In 2.2, you would have to edit
the kernel manually to disable it for your device. For 2.4, as long as
there has been blk_queue_pluggable, there has also been the
disable-merge function mentioned. Why are you disabling plugging??

-- 
Jens Axboe