Re: [PATCH 11/21] x86: get pg_data_t's memory from other node

[Tejun Heo]

On Fri, Jul 19, 2013 at 03:59:24PM +0800, Tang Chen wrote:
> From: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
> 
> If system can create movable node which all memory of the
> node is allocated as ZONE_MOVABLE, setup_node_data() cannot
> allocate memory for the node's pg_data_t.
> So, use memblock_alloc_try_nid() instead of memblock_alloc_nid()
> to retry when the first allocation fails. Otherwise, the system
> could failed to boot.
> 
> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
> Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxx>
> Signed-off-by: Tang Chen <tangchen@xxxxxxxxxxxxxx>
> Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
> Reviewed-by: Wanpeng Li <liwanp@xxxxxxxxxxxxxxxxxx>
> ---
>  arch/x86/mm/numa.c |    5 ++---
>  1 files changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
> index a71c4e2..5013583 100644
> --- a/arch/x86/mm/numa.c
> +++ b/arch/x86/mm/numa.c
> @@ -209,10 +209,9 @@ static void __init setup_node_data(int nid, u64 start, u64 end)
>  	 * Allocate node data.  Try node-local memory and then any node.
>  	 * Never allocate in DMA zone.
>  	 */
> -	nd_pa = memblock_alloc_nid(nd_size, SMP_CACHE_BYTES, nid);
> +	nd_pa = memblock_alloc_try_nid(nd_size, SMP_CACHE_BYTES, nid);
>  	if (!nd_pa) {
> -		pr_err("Cannot find %zu bytes in node %d\n",
> -		       nd_size, nid);
> +		pr_err("Cannot find %zu bytes in any node\n", nd_size);

Hmm... we want the node data to be colocated on the same node and I
don't think being hotpluggable necessarily requires the node data to
be allocated on a different node.  Does node data of a hotpluggable
node need to stay around after hotunplug?

I don't think it's a huge issue but it'd be great if we can clarify
where the restriction is coming from.

Thanks.

-- 
tejun
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