Re: s390: block/blk-iocost.c:1101:11: error: call to '__compiletime_assert_557' declared with 'error' attribute: clamp() low limit 1 greater than high limit active

['Tejun Heo' <tj@kernel.org>]

Hello,

On Wed, Dec 04, 2024 at 06:26:16PM +0000, David Laight wrote:
> > This is a good catch. It's impressive that this can be caught at compile
> > time. The upper limit can become zero but the lower limit should win as
> > that's there to protect against divide by zero, so I think the right thinig
> > to do is replacing clamp() with max(min()). Is someone interested in writing
> > up the patch and sending it Jens' way?
> 
> Perhaps if written as:
> 	inuse = min(inuse, active) ?: 1;
> it might stop someone changing it back.

And maybe some comments too. When I was writing that clamp(), the case of
min and max crossing each other didn't even cross my mind and I was dumbly
thinking just "oh, this protects the value on both fronts", so yeah, there's
some chance of someone (including myself) converting it back to clamp().

Thanks.

-- 
tejun