--- linux-2.6.4/mm/vmscan.c	2004-02-18 21:09:41.000000000 +1100
+++ linux-2.6.4-ck1/mm/vmscan.c	2004-03-11 22:18:35.267730038 +1100
@@ -41,6 +41,7 @@
  * From 0 .. 100.  Higher means more swappy.
  */
 int vm_swappiness = 60;
+int auto_swappiness = 1;
 static long total_memory;
 
 #ifdef ARCH_HAS_PREFETCH
@@ -635,6 +636,41 @@ refill_inactive_zone(struct zone *zone, 
 	 */
 	mapped_ratio = (ps->nr_mapped * 100) / total_memory;
 
+	if (auto_swappiness) {
+#ifdef CONFIG_SWAP
+		int app_percent;
+		struct sysinfo i;
+		
+		si_swapinfo(&i);
+			
+		if (likely(i.totalswap)) {
+			int swap_centile;
+	
+			/*
+			 * app_percent is the percentage of physical ram used
+			 * by application pages.
+			 */
+			si_meminfo(&i);
+			app_percent = 100 - ((i.freeram + get_page_cache_size() -
+				swapper_space.nrpages) / (i.totalram / 100));
+	
+			/*
+			 * swap_centile is the percentage of the last (sizeof physical
+			 * ram) of swap free.
+			 */
+			swap_centile = i.freeswap / 
+				(min(i.totalswap, i.totalram) / 100);
+	
+			/*
+			 * Autoregulate vm_swappiness to be equal to the lowest of
+			 * app_percent and swap_centile. -ck
+			 */
+			vm_swappiness = min(app_percent, swap_centile);
+		} else 
+			vm_swappiness = 0;
+#endif
+	}
+	
 	/*
 	 * Now decide how much we really want to unmap some pages.  The mapped
 	 * ratio is downgraded - just because there's a lot of mapped memory
--- linux-2.6.4/include/linux/swap.h	2004-02-04 22:06:06.000000000 +1100
+++ linux-2.6.4-ck1/include/linux/swap.h	2004-03-11 22:17:56.487779080 +1100
@@ -176,6 +176,7 @@ extern void swap_setup(void);
 extern int try_to_free_pages(struct zone **, unsigned int, unsigned int);
 extern int shrink_all_memory(int);
 extern int vm_swappiness;
+extern int auto_swappiness;
 
 /* linux/mm/rmap.c */
 #ifdef CONFIG_MMU
--- linux-2.6.4/include/linux/sysctl.h	2004-03-11 21:26:35.000000000 +1100
+++ linux-2.6.4-ck1/include/linux/sysctl.h	2004-03-11 22:15:46.547046694 +1100
@@ -158,6 +158,7 @@ enum
 	VM_SWAPPINESS=19,	/* Tendency to steal mapped memory */
 	VM_LOWER_ZONE_PROTECTION=20,/* Amount of protection of lower zones */
 	VM_MIN_FREE_KBYTES=21,	/* Minimum free kilobytes to maintain */
+	VM_AUTO_SWAPPINESS=22,	/* Make vm_swappiness autoregulated */
 };
 
 
--- linux-2.6.4/kernel/sysctl.c	2004-03-11 21:26:35.000000000 +1100
+++ linux-2.6.4-ck1/kernel/sysctl.c	2004-03-11 22:15:46.548046538 +1100
@@ -706,6 +706,17 @@ static ctl_table vm_table[] = {
 		.extra1		= &zero,
 		.extra2		= &one_hundred,
 	},
+	{
+		.ctl_name	= VM_AUTO_SWAPPINESS,
+		.procname	= "autoswappiness",
+		.data		= &auto_swappiness,
+		.maxlen		= sizeof(auto_swappiness),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_minmax,
+		.strategy	= &sysctl_intvec,
+		.extra1		= &zero,
+		.extra2		= &one_hundred,
+	},
 #ifdef CONFIG_HUGETLB_PAGE
 	 {
 		.ctl_name	= VM_HUGETLB_PAGES,