* Arnd Bergmann <arnd@xxxxxxxx> wrote: > On Mon, Jan 10, 2022 at 11:03 PM Arnd Bergmann <arnd@xxxxxxxx> wrote: > > On Sat, Jan 8, 2022 at 5:26 PM Ingo Molnar <mingo@xxxxxxxxxx> wrote: > > I've started building randconfig kernels for arm64 and x86, and fixing > > up things that come up, a few things I have noticed out so far: > > I have run into a couple more specific issues: > > * net/smc/smc_ib.c:824:26: error: implicit declaration of function > 'cache_line_size' [-Werror=implicit-function-declaration] > cache_line_size is generally provided by linux/cache.h, which includes > asm/cache.h. > This works on arm64, but not on x86, where asm/cache.h would have to include > asm/cpufeature.h, and but it would be good to avoid that because of the implicit > linux/percpu.h and linux/bitops.h inclusions. Also, if I add the > include, I get this > build failure instead: include/linux/smp_types.h:88:33: error: > requested alignment '20' > is not a positive power of 2 Note that this particular one should be fixed in the WIP branch, which is at: git://git.kernel.org/pub/scm/linux/kernel/git/mingo/tip.git sched/headers > * arm64 has a couple of issues around asm/memory.h, linux/mm_types.h and > asm/page.h that can cause loops. I think my latest version has it figured > out, but there is probably room for optimization. Yeah, this is like the 5th attempt at finding a robust solution. :-/ > * There is no general way to get the get_order() definition, other than > including asm/page.h from .c files. On arm64, this shows up in a couple > of files after the cleanup. Only xtensa and ia64 define their own version > of get_order(), and I think we should just remove those and move the > generic version to linux/getorder.h, where any file using it can pick it > up. For randconfig builds, I had to add asm/page.h to > net/xdp/xsk_queue.c, mm/memtest.c and > drivers/target/iscsi/iscsi_target_nego.c, after I removed the indirect > include from arch/arm64/include/asm/mmu.h in the previous step. Would including <linux/mm_page_address.h> be sufficient? That already has an <asm/page.h> inclusion and is vaguely related. I tried to avoid as many low level headers as possible from the main types headers - and the get_order() functionality also brings in bitops definitions, which I'm still hoping to be able to reduce from its current ~95% utilization in a distro kernel ... We could add <linux/page_api.h> as well, as a standardized header. We already have page_types.h and et_order() is a page types API. Thanks, Ingo
