Subject: Re: [PATCH v6 3/4] x86/vmemmap: Handle unpopulated sub-pmd ranges

From: Oscar Salvador <[email-masked]>
Date: Wed, 10 Mar 2021 08:24:17 +0100

On Wed, Mar 10, 2021 at 11:37:53AM +0530, Naresh Kamboju wrote:
> Hi Oscar,

Hi Naresh,

> While building the linux next 20210310 tag for x86_64 architecture with clang-12
> and gcc-9 the following warnings / errors were noticed.
> 
> arch/x86/mm/init_64.c:1585:6: error: implicit declaration of function
> 'vmemmap_use_new_sub_pmd' [-Werror,-Wimplicit-function-declaration]
>                                         vmemmap_use_new_sub_pmd(addr, next);
>                                         ^
> arch/x86/mm/init_64.c:1591:4: error: implicit declaration of function
> 'vmemmap_use_sub_pmd' [-Werror,-Wimplicit-function-declaration]
>                         vmemmap_use_sub_pmd(addr, next);
>                         ^
> 2 errors generated.
> make[3]: *** [scripts/Makefile.build:271: arch/x86/mm/init_64.o] Error 1
> 
> Reported-by: Naresh Kamboju <[email-masked]>

Yes, this was also reported by Zi Yan here [1].
Looking into your .config, seems to be the same issue as you have
CONFIG_SPARSE_VMEMMAP but !CONFIG_MEMORY_HOTPLUG.

This version fixes those compilation errors.

Thanks for reporting it anyway!

[1] https://lore.kernel.org/linux-mm/[email-masked]/T/#ma566ff437ff4bf8fcc5f80f62cd0cc8761edd12d

> Steps to reproduce:
> -------------------
> # TuxMake is a command line tool and Python library that provides
> # portable and repeatable Linux kernel builds across a variety of
> # architectures, toolchains, kernel configurations, and make targets.
> #
> # TuxMake supports the concept of runtimes.
> # See https://docs.tuxmake.org/runtimes/, for that to work it requires
> # that you install podman or docker on your system.
> #
> # To install tuxmake on your system globally:
> # sudo pip3 install -U tuxmake
> #
> # See https://docs.tuxmake.org/ for complete documentation.
> 
> 
> tuxmake --runtime podman --target-arch x86_64 --toolchain clang-12
> --kconfig defconfig --kconfig-add
> https://builds.tuxbuild.com/1pYCPt4WlgSfSdv1BULm6ABINeJ/config
> 
> 
> Build pipeline error link,
> https://gitlab.com/Linaro/lkft/mirrors/next/linux-next/-/jobs/1085496613#L428
> 
> -- 
> Linaro LKFT
> https://lkft.linaro.org

-- 
Oscar Salvador
SUSE L3