This commit does a couple of things:

	Re-enables the RSS limiting, and the routine is now tail-recursive,
	making it much more safe (eliminates the possiblity of kernel stack
	overflow.) Also, the RSS limiting is a little more intelligent about
	finding the likely objects that are pushing the process over the limit.

	Added some sysctls that help with VM system tuning.

New sysctl features:
	1)	Enable/disable lru pageout algorithm.
		vm.pageout_algorithm = 0, default algorithm that works
			well, especially using X windows and heavy
			memory loading.  Can have adverse effects,
			sometimes slowing down program loading.

		vm.pageout_algorithm = 1, close to true LRU.  Works much
			better than clock, etc.  Does not work as well as
			the default algorithm in general.  Certain memory
			"malloc" type benchmarks work a little better with
			this setting.

		Please give me feedback on the performance results
		associated with these.

	2)	Enable/disable swapping.
		vm.swapping_enabled = 1, default.

		vm.swapping_enabled = 0, useful for cases where swapping
			degrades performance.

		The config option "NO_SWAPPING" is still operative, and
		takes precedence over the sysctl.  If "NO_SWAPPING" is
		specified, the sysctl still exists, but "vm.swapping_enabled"
		is hard-wired to "0".

Each of these can be changed "on the fly."

1 files changed, 4 insertions, 1 deletions

diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c
index 880c3dd6f85d..4a95e6e1f1d6 100644
--- a/sys/vm/vm_page.c
+++ b/sys/vm/vm_page.c
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)vm_page.c	7.4 (Berkeley) 5/7/91
- *	$Id: vm_page.c,v 1.58 1996/06/17 03:35:37 dyson Exp $
+ *	$Id: vm_page.c,v 1.59 1996/06/21 05:39:22 dyson Exp $
  */
 
 /*
@@ -693,6 +693,7 @@ vm_page_alloc(object, pindex, page_req)
 	}
 	m->wire_count = 0;
 	m->hold_count = 0;
+	m->act_count = 0;
 	m->busy = 0;
 	m->valid = 0;
 	m->dirty = 0;
@@ -740,6 +741,8 @@ vm_page_activate(m)
 	if (m->wire_count == 0) {
 		TAILQ_INSERT_TAIL(&vm_page_queue_active, m, pageq);
 		m->queue = PQ_ACTIVE;
+		if (m->act_count < ACT_INIT)
+			m->act_count = ACT_INIT;
 		cnt.v_active_count++;
 	}
 	splx(s);