Re: [PATCH] block: blk-iocost: fix build for ARCH with missing local64.h files

[Christoph Hellwig]

On Wed, Dec 09, 2020 at 10:16:20PM -0800, Randy Dunlap wrote:
> include/asm-generic/local64.h has comments about some $arch could do
> its things better/faster instead of using asm-generic, but no $arch has
> done that since 2010 when it was added.
> 
> Is that conclusive?
> If it is, why even use mandatory-y?
> Why not just change all occurrences of <asm/local64.h>
> to <asm-generic/local64.h> ?

asm-generic must not be included by non-arch code directly.  So the
sensible options are either:

 a) mark it as mandatory-y in include/asm-generic/Kbuild
 b) rename it to linux/local64.h and fixup all references

a) seems much less invasive, but b) might be the better option long
term.