On Wed, Dec 09, 2020 at 10:16:20PM -0800, Randy Dunlap wrote: > On 12/9/20 10:07 PM, Christoph Hellwig wrote: > > On Wed, Dec 09, 2020 at 12:46:57PM -0800, Randy Dunlap wrote: > >> When building block/blk-iocost.c on arch/x6x/ or arch/nios2/, the > >> build fails due to missing the <asm/local64.h> file. > > > > Please mark it mandatory-y if the asm-generic version is suitable > > for everyone and random pieces of kernel code are supposed to include > > it. > > 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. Yeah, it's only 32bit archs, and of those I'm only sure i386 could do it better, very maybe arm-v7. But nobody cares enough to make it happen. All the 64bit archs are already good, because local_t is long and local64_t defaults to local_t.