Re: [PATCH] Section mismatch contig_page_data and bootmem_node_data

From: Marcin Slusarz
Date: Wed Aug 20 2008 - 15:06:23 EST


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@xxxxxxxxxxxx>
> ---
> 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
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