Re: kernel/sched/fair.c:9246:53: error: use of undeclared identifier 'select_idle_mask'

[Dietmar Eggemann <dietmar.eggemann@arm.com>]

On 22/06/2022 06:13, kernel test robot wrote:
> tree:   https://github.com/intel-lab-lkp/linux/commits/Vincent-Donnefort/feec-energy-margin-removal/20220621-170631
> head:   2059fff7a5a2b6016ef5843c673845283a00a646
> commit: a4a1ec79913664ac49b72cda8c3756c4da7c16b4 sched/fair: Rename select_idle_mask to select_rq_mask
> date:   19 hours ago
> config: s390-randconfig-r044-20220622 (https://download.01.org/0day-ci/archive/20220622/202206221253.ZVyGQvPX-lkp@intel.com/config)
> compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 8b8d126598ce7bd5243da7f94f69fa1104288bee)
> 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 s390 cross compiling tool for clang build
>         # apt-get install binutils-s390x-linux-gnu
>         # https://github.com/intel-lab-lkp/linux/commit/a4a1ec79913664ac49b72cda8c3756c4da7c16b4
>         git remote add linux-review https://github.com/intel-lab-lkp/linux
>         git fetch --no-tags linux-review Vincent-Donnefort/feec-energy-margin-removal/20220621-170631
>         git checkout a4a1ec79913664ac49b72cda8c3756c4da7c16b4
>         # save the config file
>         mkdir build_dir && cp config build_dir/.config
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash kernel/
> 

[...]

>>> kernel/sched/fair.c:9246:53: error: use of undeclared identifier 'select_idle_mask'
>                                    struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_idle_mask);
>                                                                                    ^
>>> kernel/sched/fair.c:9246:53: error: use of undeclared identifier 'select_idle_mask'
>>> kernel/sched/fair.c:9246:53: error: use of undeclared identifier 'select_idle_mask'
>>> kernel/sched/fair.c:9246:21: error: initializing 'struct cpumask *' with an expression of incompatible type 'void'
>                                    struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_idle_mask);
>                                                    ^      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This is due to commit f5b2eeb499910 ("sched/fair: Consider CPU affinity
when allowing NUMA imbalance in find_idlest_group()") which appeared on
tip sched/core and linux-next in the meantime.

Fixed in
https://lkml.kernel.org/r/250691c7-0e2b-05ab-bedf-b245c11d9400@arm.com .

Thanks!