---

 linux-2.6-npiggin/include/linux/mmzone.h |   37 +++++++++++++++----------------
 1 files changed, 19 insertions(+), 18 deletions(-)

diff -puN include/linux/mmzone.h~mm-help-zone-padding include/linux/mmzone.h
--- linux-2.6/include/linux/mmzone.h~mm-help-zone-padding	2004-10-22 08:21:30.000000000 +1000
+++ linux-2.6-npiggin/include/linux/mmzone.h	2004-10-22 08:24:09.000000000 +1000
@@ -35,7 +35,7 @@ struct pglist_data;
  */
 #if defined(CONFIG_SMP)
 struct zone_padding {
-	int x;
+	char x[0];
 } ____cacheline_maxaligned_in_smp;
 #define ZONE_PADDING(name)	struct zone_padding name;
 #else
@@ -108,10 +108,7 @@ struct per_cpu_pageset {
  */
 
 struct zone {
-	/*
-	 * Commonly accessed fields:
-	 */
-	spinlock_t		lock;
+	/* Fields commonly accessed by the page allocator */
 	unsigned long		free_pages;
 	unsigned long		pages_min, pages_low, pages_high;
 	/*
@@ -128,8 +125,18 @@ struct zone {
 	 */
 	unsigned long		protection[MAX_NR_ZONES];
 
+	struct per_cpu_pageset	pageset[NR_CPUS];
+
+	/*
+	 * free areas of different sizes
+	 */
+	spinlock_t		lock;
+	struct free_area	free_area[MAX_ORDER];
+
+
 	ZONE_PADDING(_pad1_)
 
+	/* Fields commonly accessed by the page reclaim scanner */
 	spinlock_t		lru_lock;	
 	struct list_head	active_list;
 	struct list_head	inactive_list;
@@ -137,10 +144,8 @@ struct zone {
 	unsigned long		nr_scan_inactive;
 	unsigned long		nr_active;
 	unsigned long		nr_inactive;
-	int			all_unreclaimable; /* All pages pinned */
 	unsigned long		pages_scanned;	   /* since last reclaim */
-
-	ZONE_PADDING(_pad2_)
+	int			all_unreclaimable; /* All pages pinned */
 
 	/*
 	 * prev_priority holds the scanning priority for this zone.  It is
@@ -161,10 +166,9 @@ struct zone {
 	int temp_priority;
 	int prev_priority;
 
-	/*
-	 * free areas of different sizes
-	 */
-	struct free_area	free_area[MAX_ORDER];
+	
+	ZONE_PADDING(_pad2_)
+	/* Rarely used or read-mostly fields */
 
 	/*
 	 * wait_table		-- the array holding the hash table
@@ -194,10 +198,6 @@ struct zone {
 	unsigned long		wait_table_size;
 	unsigned long		wait_table_bits;
 
-	ZONE_PADDING(_pad3_)
-
-	struct per_cpu_pageset	pageset[NR_CPUS];
-
 	/*
 	 * Discontig memory support fields.
 	 */
@@ -206,12 +206,13 @@ struct zone {
 	/* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
 	unsigned long		zone_start_pfn;
 
+	unsigned long		spanned_pages;	/* total size, including holes */
+	unsigned long		present_pages;	/* amount of memory (excluding holes) */
+
 	/*
 	 * rarely used fields:
 	 */
 	char			*name;
-	unsigned long		spanned_pages;	/* total size, including holes */
-	unsigned long		present_pages;	/* amount of memory (excluding holes) */
 } ____cacheline_maxaligned_in_smp;
 
 

_