Re: [PATCH] Section mismatch contig_page_data and bootmem_node_data

[Marcin Slusarz <marcin.slusarz@gmail.com>]

On Wed, Aug 20, 2008 at 01:55:51PM -0400, Sean MacLennan wrote:
> If CONFIG_NEED_MULTIPLE_NODES is *not* set, then you get a section
> mismatch in reference from the variable contig_page_data to the
> variable __initdata bootmem_node_data.
> 
> The simple solution is to just remove the __initdata from
> bootmem_node_data. We could also put an ifdef around the __initdata.
> 
> Signed-off-by: Sean MacLennan <smaclennan@pikatech.com>
> ---
> diff --git a/mm/bootmem.c b/mm/bootmem.c
> index e023c68..a968ae2 100644
> --- a/mm/bootmem.c
> +++ b/mm/bootmem.c
> @@ -31,7 +31,7 @@ unsigned long max_pfn;
>  unsigned long saved_max_pfn;
>  #endif
>  
> -bootmem_data_t bootmem_node_data[MAX_NUMNODES] __initdata;
> +bootmem_data_t bootmem_node_data[MAX_NUMNODES];
>  
>  static struct list_head bdata_list __initdata = LIST_HEAD_INIT(bdata_list);
>  
> --

I thought about this warning today and found 2 other solutions:
1) Mark contig_page_data as __ref (but it might hide real bugs).
2) Remove bdata from struct pglist_data and access it directly through
   bootmem_node_data. It requires passing node number to all functions
   which use bdata, but unfortunately arch/ia64/mm/discontig.c handles
   node numbering its own way. I'm still investigating it.

Marcin