[PATCH 4/4] mm: move highest_memmap_pfn

Hugh Dickins
2009-09-15T20:39:06Z

Move highest_memmap_pfn __read_mostly from page_alloc.c next to
zero_pfn __read_mostly in memory.c: to help them share a cacheline,
since they're very often tested together in vm_normal_page().

Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
---

mm/internal.h | 3 ++-
mm/memory.c | 1 +
mm/page_alloc.c | 1 -
3 files changed, 3 insertions(+), 2 deletions(-)

--- mm3/mm/internal.h 2009-09-14 16:34:37.000000000 +0100
+++ mm4/mm/internal.h 2009-09-15 17:32:27.000000000 +0100
@@ -37,6 +37,8 @@ static inline void __put_page(struct pag
atomic_dec(&page->_count);
}

+extern unsigned long highest_memmap_pfn;
+
/*
* in mm/vmscan.c:
*/
@@ -46,7 +48,6 @@ extern void putback_lru_page(struct page
/*
* in mm/page_alloc.c
*/
-extern unsigned long highest_memmap_pfn;
extern void __free_pages_bootmem(struct page *page, unsigned int order);
extern void prep_compound_page(struct page *page, unsigned long order);

--- mm3/mm/memory.c 2009-09-15 17:32:19.000000000 +0100
+++ mm4/mm/memory.c 2009-09-15 17:32:27.000000000 +0100
@@ -108,6 +108,7 @@ static int __init disable_randmaps(char
__setup("norandmaps", disable_randmaps);

unsigned long zero_pfn __read_mostly;
+unsigned long highest_memmap_pfn __read_mostly;

/*
* CONFIG_MMU architectures set up ZERO_PAGE in their paging_init()
--- mm3/mm/page_alloc.c 2009-09-14 16:34:37.000000000 +0100
+++ mm4/mm/page_alloc.c 2009-09-15 17:32:27.000000000 +0100
@@ -72,7 +72,6 @@ EXPORT_SYMBOL(node_states);

unsigned long totalram_pages __read_mostly;
unsigned long totalreserve_pages __read_mostly;
-unsigned long highest_memmap_pfn __read_mostly;
int percpu_pagelist_fraction;
gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;