Re: kernel/sched/fair.c:9551:12: warning: stack frame size of 1376 bytes in function 'load_balance'

From: Arnd Bergmann
Date: Wed May 19 2021 - 08:33:52 EST


On Mon, May 17, 2021 at 3:45 PM Vincent Guittot
<vincent.guittot@xxxxxxxxxx> wrote:
>
> On Tue, 11 May 2021 at 18:01, kernel test robot <lkp@xxxxxxxxx> wrote:
> >
> > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > head: 1140ab592e2ebf8153d2b322604031a8868ce7a5
> > commit: 0826530de3cbdc89e60a89e86def94a5f0fc81ca sched/fair: Remove update of blocked load from newidle_balance
> > date: 9 weeks ago
> > config: mips-randconfig-r022-20210511 (attached as .config)
> > compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project a0fed635fe1701470062495a6ffee1c608f3f1bc)
> > reproduce (this is a W=1 build):
> > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> > chmod +x ~/bin/make.cross
> > # install mips cross compiling tool for clang build
> > # apt-get install binutils-mips-linux-gnu
> > # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0826530de3cbdc89e60a89e86def94a5f0fc81ca
> > git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> > git fetch --no-tags linus master
> > git checkout 0826530de3cbdc89e60a89e86def94a5f0fc81ca
> > # save the attached .config to linux build tree
> > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=mips
>
> It was a bit difficult to find the warning among the thousand

I opened an issue against clang about it:

See https://github.com/ClangBuiltLinux/linux/issues/1379

but then found that this is already known. I think it would be best to
make the kernel test robot
set CONFIG_COMPILE_TEST to avoid issues like this. I have annotated a
number of symbols
that are known to cause unnecessary false positives in a similar way
to get a clean build.

Arnd