Re: remove dead bdi congestion leftovers

[Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>]

On Thu, Jul 09, 2020 at 07:58:58AM -0600, Jens Axboe wrote:
> On 7/8/20 11:32 PM, Christoph Hellwig wrote:
> > On Wed, Jul 08, 2020 at 05:14:29PM -0600, Jens Axboe wrote:
> >> On 7/1/20 3:06 AM, Christoph Hellwig 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.
> >>
> >> Please run series like this through a full compilation, for both this one
> >> and the previous series I had to fix up issues like this:
> >>
> >> drivers/md/bcache/request.c: In function ‘bch_cached_dev_request_init’:
> >> drivers/md/bcache/request.c:1233:18: warning: unused variable ‘g’ [-Wunused-variable]
> >>  1233 |  struct gendisk *g = dc->disk.disk;
> >>       |                  ^
> >> drivers/md/bcache/request.c: In function ‘bch_flash_dev_request_init’:
> >> drivers/md/bcache/request.c:1320:18: warning: unused variable ‘g’ [-Wunused-variable]
> >>  1320 |  struct gendisk *g = d->disk;
> >>       |                  ^
> >>
> >> Did the same here, applied it.
> > 
> > And just like the previous one I did, and the compiler did not complain.
> > There must be something about certain gcc versions not warning about
> > variables that are initialized but not otherwise used.
> 
> Are you using gcc-10? It sucks for that. gcc-9 seems to reliably hit
> these cases for me, not sure why gcc-10 doesn't. And the ones quoted
> above are about as trivial as they can get.

gcc-9.3 from Debian -testing.  And yes, I'm really surprised it didn't
find those.