[PATCH] don't pass mem_map into init functions

  When using CONFIG_NONLINEAR, a zone's mem_map isn't contiguous, and isn't
  allocated in the same place.  This means that nonlinear doesn't really have
  a mem_map[] to pass into free_area_init_node() or memmap_init_zone() which
  makes any sense.

  So, this patch removes the 'struct page *mem_map' argument to both of
  those functions.  All non-NUMA architectures just pass a NULL in there,
  which is ignored.  The solution on the NUMA arches is to pass the mem_map in
  via the pgdat, which works just fine.

  To replace the removed arguments, a call to pfn_to_page(node_start_pfn) is
  made.  This is valid because all of the pfn_to_page() implementations rely
  only on the pgdats, which are already set up at this time.  Plus, the
  pfn_to_page() method should work for any future nonlinear-type code.  

  Finally, the patch creates a function: node_alloc_mem_map(), which I plan
  to effectively #ifdef out for nonlinear at some future date. 

  Compile tested and booted on SMP x86, NUMAQ, and ppc64.

From: Jesse Barnes <jbarnes@engr.sgi.com>

  Fix up ia64 specific memory map init function in light of Dave's
  memmap_init cleanups.

Signed-off-by: Jesse Barnes <jbarnes@sgi.com>

From: Dave Hansen <haveblue@us.ibm.com>

  Looks like I missed a couple of architectures.  This patch, on top of my
  previous one and Jesse's should clean up the rest.

From: William Lee Irwin III <wli@holomorphy.com>

  x86-64 wouldn't compile with NUMA support on, as node_alloc_mem_map()
  references mem_map outside #ifdefs on CONFIG_NUMA/CONFIG_DISCONTIGMEM.  This
  patch wraps that reference in such an #ifdef.

From: William Lee Irwin III <wli@holomorphy.com>

  Initializing NODE_DATA(nid)->node_mem_map prior to calling it should do.

From: Dave Hansen <haveblue@us.ibm.com>

  Rick, I bet you didn't think your nerf weapons would be so effective in
  getting that compile error fixed, did you?

  Applying the attached patch and commenting out this line:

  arch/i386/kernel/nmi.c: In function `proc_unknown_nmi_panic':
  arch/i386/kernel/nmi.c:558: too few arguments to function `proc_dointvec'

  will let it compile.  

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 23 insertions, 18 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 62be1c9e9c85ba..aa5cfa69e584a5 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1383,9 +1383,10 @@ static void __init calculate_zone_totalpages(struct pglist_data *pgdat,
  * up by free_all_bootmem() once the early boot process is
  * done. Non-atomic initialization, single-pass.
  */
-void __init memmap_init_zone(struct page *start, unsigned long size, int nid,
-		unsigned long zone, unsigned long start_pfn)
+void __init memmap_init_zone(unsigned long size, int nid, unsigned long zone,
+		unsigned long start_pfn)
 {
+	struct page *start = pfn_to_page(start_pfn);
 	struct page *page;
 
 	for (page = start; page < (start + size); page++) {
@@ -1449,8 +1450,8 @@ void zone_init_free_lists(struct pglist_data *pgdat, struct zone *zone, unsigned
 }
 
 #ifndef __HAVE_ARCH_MEMMAP_INIT
-#define memmap_init(start, size, nid, zone, start_pfn) \
-	memmap_init_zone((start), (size), (nid), (zone), (start_pfn))
+#define memmap_init(size, nid, zone, start_pfn) \
+	memmap_init_zone((size), (nid), (zone), (start_pfn))
 #endif
 
 /*
@@ -1465,7 +1466,6 @@ static void __init free_area_init_core(struct pglist_data *pgdat,
 	unsigned long i, j;
 	const unsigned long zone_required_alignment = 1UL << (MAX_ORDER-1);
 	int cpu, nid = pgdat->node_id;
-	struct page *lmem_map = pgdat->node_mem_map;
 	unsigned long zone_start_pfn = pgdat->node_start_pfn;
 
 	pgdat->nr_zones = 0;
@@ -1553,35 +1553,41 @@ static void __init free_area_init_core(struct pglist_data *pgdat,
 
 		pgdat->nr_zones = j+1;
 
-		zone->zone_mem_map = lmem_map;
+		zone->zone_mem_map = pfn_to_page(zone_start_pfn);
 		zone->zone_start_pfn = zone_start_pfn;
 
 		if ((zone_start_pfn) & (zone_required_alignment-1))
 			printk("BUG: wrong zone alignment, it will crash\n");
 
-		memmap_init(lmem_map, size, nid, j, zone_start_pfn);
+		memmap_init(size, nid, j, zone_start_pfn);
 
 		zone_start_pfn += size;
-		lmem_map += size;
 
 		zone_init_free_lists(pgdat, zone, zone->spanned_pages);
 	}
 }
 
-void __init free_area_init_node(int nid, struct pglist_data *pgdat,
-		struct page *node_mem_map, unsigned long *zones_size,
-		unsigned long node_start_pfn, unsigned long *zholes_size)
+void __init node_alloc_mem_map(struct pglist_data *pgdat)
 {
 	unsigned long size;
 
+	size = (pgdat->node_spanned_pages + 1) * sizeof(struct page);
+	pgdat->node_mem_map = alloc_bootmem_node(pgdat, size);
+#ifndef CONFIG_DISCONTIGMEM
+	mem_map = contig_page_data.node_mem_map;
+#endif
+}
+
+void __init free_area_init_node(int nid, struct pglist_data *pgdat,
+		unsigned long *zones_size, unsigned long node_start_pfn,
+		unsigned long *zholes_size)
+{
 	pgdat->node_id = nid;
 	pgdat->node_start_pfn = node_start_pfn;
 	calculate_zone_totalpages(pgdat, zones_size, zholes_size);
-	if (!node_mem_map) {
-		size = (pgdat->node_spanned_pages + 1) * sizeof(struct page);
-		node_mem_map = alloc_bootmem_node(pgdat, size);
-	}
-	pgdat->node_mem_map = node_mem_map;
+
+	if (!pfn_to_page(node_start_pfn))
+		node_alloc_mem_map(pgdat);
 
 	free_area_init_core(pgdat, zones_size, zholes_size);
 }
@@ -1594,9 +1600,8 @@ EXPORT_SYMBOL(contig_page_data);
 
 void __init free_area_init(unsigned long *zones_size)
 {
-	free_area_init_node(0, &contig_page_data, NULL, zones_size,
+	free_area_init_node(0, &contig_page_data, zones_size,
 			__pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
-	mem_map = contig_page_data.node_mem_map;
 }
 #endif