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Fix alloc_node_mem_map() to work on ia64 again

PATCH New Tony Luck 1 participant 1 message Nov 10, 2015

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Tony Luck

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PATCH 1/1 Fix alloc_node_mem_map() to work on ia64 again

In commit a1c34a3bf00af2cede839879502e12dc68491ad5
"mm: Don't offset memmap for flatmem"

Laura fixed a problem for Srinivas relating to the bottom 2MB of RAM on an ARM IFC6410 board.

One small wrinkle on ia64 is that it allocates the node_mem_map earlier in arch code, so it skips the block of code where "offset" is initialized.

Move initialization of start and offset before the check for the node_mem_map so that they will always be available in the latter part of the function.

Tested-by Laura Abbott <[email protected]>
Fixes a1c34a3bf00a (mm: Don't offset memmap for flatmem)
Signed-off-by Tony Luck <[email protected]>
---
 mm/page_alloc.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)
mm/page_alloc.c +4 -3
index 208e4c7e771b..17a3c66639a9 100644
@@ -5266,6 +5266,7 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat)
 
 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
 {
+	unsigned long __maybe_unused start = 0;
 	unsigned long __maybe_unused offset = 0;
 
 	/* Skip empty nodes */

@@ -5273,9 +5274,11 @@ static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
 		return;
 
 #ifdef CONFIG_FLAT_NODE_MEM_MAP
+	start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
+	offset = pgdat->node_start_pfn - start;
 	/* ia64 gets its own node_mem_map, before this, without bootmem */
 	if (!pgdat->node_mem_map) {
-		unsigned long size, start, end;
+		unsigned long size, end;
 		struct page *map;
 
 		/*

@@ -5283,8 +5286,6 @@ static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
 		 * aligned but the node_mem_map endpoints must be in order
 		 * for the buddy allocator to function correctly.
 		 */
-		start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
-		offset = pgdat->node_start_pfn - start;
 		end = pgdat_end_pfn(pgdat);
 		end = ALIGN(end, MAX_ORDER_NR_PAGES);
 		size =  (end - start) * sizeof(struct page);
Signature · 1 line
2.1.4