Re: [PATCH v2 3/7] x86, gfp: Cache best near node for memory allocation.

[Tejun Heo]

Hello,

On Thu, Sep 10, 2015 at 12:27:45PM +0800, Tang Chen wrote:
> diff --git a/include/linux/gfp.h b/include/linux/gfp.h
> index ad35f30..1a1324f 100644
> --- a/include/linux/gfp.h
> +++ b/include/linux/gfp.h
> @@ -307,13 +307,19 @@ static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
>  	if (nid < 0)
>  		nid = numa_node_id();
>  
> +	if (!node_online(nid))
> +		nid = get_near_online_node(nid);
> +
>  	return __alloc_pages(gfp_mask, order, node_zonelist(nid, gfp_mask));
>  }

Why not just update node_data[]->node_zonelist in the first place?
Also, what's the synchronization rule here?  How are allocators
synchronized against node hot [un]plugs?

Thanks.

-- 
tejun
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/