[dm-devel] remove dead bdi congestion leftovers

[Matthew Wilcox]

On Wed, Jul 01, 2020 at 12:41:03PM -0400, Mike Snitzer wrote:
> On Wed, Jul 01 2020 at  5:06am -0400,
> Christoph Hellwig <hch at lst.de> wrote:
> 
> > Hi Jens,
> > 
> > we have a lot of bdi congestion related code that is left around without
> > any use.  This series removes it in preparation of sorting out the bdi
> > lifetime rules properly.
> 
> I could do some git archeology to see what the fs, mm and block core
> changes were to stop using bdi congested but a pointer to associated
> changes (or quick recap) would save me some time.
> 
> Also, curious to know how back-pressure should be felt back up the IO
> stack now? (apologies if these are well worn topics, I haven't been
> tracking this area of development).

It isn't.  Jens declared the implementation was broken, and broke it
more.  So we're just living with stupid broken timeouts.