Re: kernel/sched/isolation.c:50: undefined reference to `sched_numa_find_closest'

[Ingo Molnar <mingo@kernel.org>]

* Oleg Nesterov <oleg@redhat.com> wrote:

> On 03/26, kernel test robot wrote:
> >
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > head:   2d09a9449ecd9a2b9fdac62408c12ee20b6307d2
> > commit: 5097cbcb38e6e0d2627c9dde1985e91d2c9f880e sched/isolation: Prevent boot crash when the boot CPU is nohz_full
> > date:   11 months ago
> > config: sh-randconfig-r132-20250326 (https://download.01.org/0day-ci/archive/20250326/202503260646.lrUqD3j5-lkp@intel.com/config)
> ...
> > >> kernel/sched/isolation.c:50: undefined reference to `sched_numa_find_closest'
> 
> kernel/sched/isolation.c makes no sense without CONFIG_SMP, but
> 
> 	config CPU_ISOLATION
> 		bool "CPU isolation"
> 		depends on SMP || COMPILE_TEST
> 
> and .config above has CONFIG_COMPILE_TEST but not CONFIG_SMP.
> 
> It also has CONFIG_NUMA, it doesn't depend on CONFIG_SMP in
> arch/sh/mm/Kconfig, so isolation.c can't use the dummy version
> of sched_numa_find_closest() in kernel/sched/sched.h, and
> kernel/sched/build_utility.c doesn't include topology.c without
> CONFIG_SMP.
> 
> Perhaps we can should simply remove this "|| COMPILE_TEST" ?
> 
> Oleg.
> 
> --- x/init/Kconfig
> +++ x/init/Kconfig
> @@ -709,7 +709,7 @@ endmenu # "CPU/Task time and stats accou
>  
>  config CPU_ISOLATION
>  	bool "CPU isolation"
> -	depends on SMP || COMPILE_TEST
> +	depends on SMP
>  	default y
>  	help
>  	  Make sure that CPUs running critical tasks are not disturbed by

Yeah, please send a patch with a SOB.

Thanks,

	Ingo