[RFC PATCH v3 1/3] powerpc: Fix warning reported by verify_cpu_node_mapping()

[Nishanth Aravamudan]

Ben & Michael,

What's the status of these patches?

Thanks,
Nish

On 27.08.2014 [17:33:59 +0800], Li Zhong wrote:
> With commit 2fabf084b6ad ("powerpc: reorder per-cpu NUMA information's
> initialization"), during boottime, cpu_numa_callback() is called
> earlier(before their online) for each cpu, and verify_cpu_node_mapping()
> uses cpu_to_node() to check whether siblings are in the same node.
> 
> It skips the checking for siblings that are not online yet. So the only
> check done here is for the bootcpu, which is online at that time. But
> the per-cpu numa_node cpu_to_node() uses hasn't been set up yet (which
> will be set up in smp_prepare_cpus()).
> 
> So I saw something like following reported:
> [    0.000000] CPU thread siblings 1/2/3 and 0 don't belong to the same
> node!
> 
> As we don't actually do the checking during this early stage, so maybe
> we could directly call numa_setup_cpu() in do_init_bootmem().
> 
> Cc: Nishanth Aravamudan <nacc at linux.vnet.ibm.com>
> Cc: Nathan Fontenot <nfont at linux.vnet.ibm.com>
> Signed-off-by: Li Zhong <zhong at linux.vnet.ibm.com>
> ---
>  arch/powerpc/mm/numa.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
> index d7737a5..9918c02 100644
> --- a/arch/powerpc/mm/numa.c
> +++ b/arch/powerpc/mm/numa.c
> @@ -1128,8 +1128,7 @@ void __init do_init_bootmem(void)
>  	 * early in boot, cf. smp_prepare_cpus().
>  	 */
>  	for_each_possible_cpu(cpu) {
> -		cpu_numa_callback(&ppc64_numa_nb, CPU_UP_PREPARE,
> -				  (void *)(unsigned long)cpu);
> +		numa_setup_cpu((unsigned long)cpu);
>  	}
>  }
> 
> -- 
> 1.9.1
>