Re: [PATCH 1/4] x86, numa: Do not scan two times forsetup_node_bootmem()

From: David Rientjes
Date: Sat Feb 19 2011 - 23:03:57 EST


On Fri, 18 Feb 2011, Yinghai Lu wrote:

>
> We don't need to scan two times for setup_node_bootmem()
> because We are using mapped memblock for node_data finding already.
>
> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
>
> ---
> arch/x86/mm/numa_64.c | 31 +++++++++++++------------------
> 1 file changed, 13 insertions(+), 18 deletions(-)
>
> Index: linux-2.6/arch/x86/mm/numa_64.c
> ===================================================================
> --- linux-2.6.orig/arch/x86/mm/numa_64.c
> +++ linux-2.6/arch/x86/mm/numa_64.c
> @@ -480,7 +480,7 @@ static bool __init numa_meminfo_cover_me
>
> static int __init numa_register_memblks(struct numa_meminfo *mi)
> {
> - int i, j, nid;
> + int i, nid;
>
> /* Account for nodes with cpus and no memory */
> node_possible_map = numa_nodes_parsed;
> @@ -507,27 +507,22 @@ static int __init numa_register_memblks(
> init_memory_mapping_high();
>
> /*
> - * Finally register nodes. Do it twice in case setup_node_bootmem
> - * missed one due to missing bootmem.
> + * Do not do that twice, not needed!
> + * We are using mapped memblock directly for node data

I don't think this comment is actually needed, it seems to be referring to
why this patch is changing it and has no real relevance once it's merged.

Other than that:

Acked-by: David Rientjes <rientjes@xxxxxxxxxx>

> */
> - for (i = 0; i < 2; i++) {
> - for_each_node_mask(nid, node_possible_map) {
> - u64 start = (u64)max_pfn << PAGE_SHIFT;
> - u64 end = 0;
> + for_each_node_mask(nid, node_possible_map) {
> + u64 start = (u64)max_pfn << PAGE_SHIFT;
> + u64 end = 0;
>
> - if (node_online(nid))
> + for (i = 0; i < mi->nr_blks; i++) {
> + if (nid != mi->blk[i].nid)
> continue;
> -
> - for (j = 0; j < mi->nr_blks; j++) {
> - if (nid != mi->blk[j].nid)
> - continue;
> - start = min(mi->blk[j].start, start);
> - end = max(mi->blk[j].end, end);
> - }
> -
> - if (start < end)
> - setup_node_bootmem(nid, start, end);
> + start = min(mi->blk[i].start, start);
> + end = max(mi->blk[i].end, end);
> }
> +
> + if (start < end)
> + setup_node_bootmem(nid, start, end);
> }
>
> return 0;
>
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