From 2bdaf115b1c364d89484b59d5b937973f1c5a5c3 Mon Sep 17 00:00:00 2001 From: Andy Whitcroft Date: Fri, 6 Jan 2006 00:10:53 -0800 Subject: [PATCH] [PATCH] flatmem split out memory model There are three places we define pfn_to_nid(). Two in linux/mmzone.h and one in asm/mmzone.h. These in essence represent the three memory models. The definition in linux/mmzone.h under !NEED_MULTIPLE_NODES is both the FLATMEM definition and the optimisation for single NUMA nodes; the one under SPARSEMEM is the NUMA sparsemem one; the one in asm/mmzone.h under DISCONTIGMEM is the discontigmem one. This is not in the least bit obvious, particularly the connection between the non-NUMA optimisations and the memory models. Two patches: flatmem-split-out-memory-model: simplifies the selection of pfn_to_nid() implementations. The selection is based primarily off the memory model selected. Optimisations for non-NUMA are applied where needed. sparse-provide-pfn_to_nid: implement pfn_to_nid() for SPARSEMEM This patch: pfn_to_nid is memory model specific The pfn_to_nid() call is memory model specific. It represents the locality identifier for the memory passed. Classically this would be a NUMA node, but not a chunk of memory under DISCONTIGMEM. The SPARSEMEM and FLATMEM memory model non-NUMA versions of pfn_to_nid() are folded together under NEED_MULTIPLE_NODES, while DISCONTIGMEM has its own optimisation. This is all very confusing. This patch splits out each implementation of pfn_to_nid() so that we can see them and the optimisations to each. Signed-off-by: Andy Whitcroft Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mmzone.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index d294b57a4016..ee9f7b74e613 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -435,7 +435,6 @@ extern struct pglist_data contig_page_data; #define NODE_DATA(nid) (&contig_page_data) #define NODE_MEM_MAP(nid) mem_map #define MAX_NODES_SHIFT 1 -#define pfn_to_nid(pfn) (0) #else /* CONFIG_NEED_MULTIPLE_NODES */ @@ -470,6 +469,10 @@ extern struct pglist_data contig_page_data; #define early_pfn_to_nid(nid) (0UL) #endif +#ifdef CONFIG_FLATMEM +#define pfn_to_nid(pfn) (0) +#endif + #define pfn_to_section_nr(pfn) ((pfn) >> PFN_SECTION_SHIFT) #define section_nr_to_pfn(sec) ((sec) << PFN_SECTION_SHIFT) @@ -594,6 +597,8 @@ static inline int pfn_valid(unsigned long pfn) */ #ifdef CONFIG_NUMA #define pfn_to_nid early_pfn_to_nid +#else +#define pfn_to_nid(pfn) (0) #endif #define early_pfn_valid(pfn) pfn_valid(pfn)