From c555e520ef794a94dc36a8ded93ece6369ff7ca0 Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Tue, 9 Dec 2008 08:21:32 +0000 Subject: powerpc/mm: Add better comment on careful_allocation() The behavior in careful_allocation() really confused me at first. Add a comment to hopefully make it easier on the next doofus that looks at it. Signed-off-by: Dave Hansen Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/mm/numa.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'arch/powerpc') diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index cf81049e1e51..213664c9cdca 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -840,8 +840,16 @@ static void __init *careful_allocation(int nid, unsigned long size, size, nid); /* - * If the memory came from a previously allocated node, we must - * retry with the bootmem allocator. + * We initialize the nodes in numeric order: 0, 1, 2... + * and hand over control from the LMB allocator to the + * bootmem allocator. If this function is called for + * node 5, then we know that all nodes <5 are using the + * bootmem allocator instead of the LMB allocator. + * + * So, check the nid from which this allocation came + * and double check to see if we need to use bootmem + * instead of the LMB. We don't free the LMB memory + * since it would be useless. */ new_nid = early_pfn_to_nid(ret >> PAGE_SHIFT); if (new_nid < nid) { -- cgit v1.2.3