From: Dave Hansen The following four patches provide the last needed changes before the introduction of sparsemem. For a more complete description of what this will do, please see this patch: http://www.sr71.net/patches/2.6.11/2.6.11-bk7-mhp1/broken-out/B-sparse-150-sparsemem.patch or previous posts on the subject: http://marc.theaimsgroup.com/?t=110868540700001&r=1&w=2 http://marc.theaimsgroup.com/?l=linux-mm&m=109897373315016&w=2 Three of these are i386-only, but one of them reorganizes the macros used to manage the space in page->flags, and will affect all platforms. There are analogous patches to the i386 ones for ppc64, ia64, and x86_64, but those will be submitted by the normal arch maintainers. The combination of the four patches has been test-booted on a variety of i386 hardware, and compiled for ppc64, i386, and x86-64 with about 17 different .configs. It's also been runtime-tested on ia64 configs (with more patches on top). This patch: We _know_ which node pages in general belong to, at least at a very gross level in node_{start,end}_pfn[]. Use those to target the allocations of pages. Signed-off-by: Andy Whitcroft Signed-off-by: Dave Hansen Signed-off-by: Andrew Morton --- 25-akpm/arch/i386/mm/discontig.c | 15 +++++++++++++++ 1 files changed, 15 insertions(+) diff -puN arch/i386/mm/discontig.c~resubmit-sparsemem-base-early_pfn_to_nid-works-before-sparse-is-initialized arch/i386/mm/discontig.c --- 25/arch/i386/mm/discontig.c~resubmit-sparsemem-base-early_pfn_to_nid-works-before-sparse-is-initialized 2005-03-28 15:56:01.000000000 -0800 +++ 25-akpm/arch/i386/mm/discontig.c 2005-03-28 15:56:01.000000000 -0800 @@ -146,6 +146,21 @@ static void __init find_max_pfn_node(int BUG(); } +/* Find the owning node for a pfn. */ +int early_pfn_to_nid(unsigned long pfn) +{ + int nid; + + for_each_node(nid) { + if (node_end_pfn[nid] == 0) + break; + if (node_start_pfn[nid] <= pfn && node_end_pfn[nid] >= pfn) + return nid; + } + + return 0; +} + /* * Allocate memory for the pg_data_t for this node via a crude pre-bootmem * method. For node zero take this from the bottom of memory, for _