From a29b63cb739723c4874f328af2cbdfac80d184bd Mon Sep 17 00:00:00 2001
From: John Dyson <dyson@FreeBSD.org>
Date: Sun, 3 Sep 1995 20:39:22 +0000
Subject: [PATCH] Machine dependent routines to support pre-zeroed free pages. 
 This significantly improves demand zero performance.

---
 sys/amd64/amd64/cpu_switch.S |  5 ++++-
 sys/amd64/amd64/swtch.s      |  5 ++++-
 sys/amd64/amd64/vm_machdep.c | 21 ++++++++++++++++++++-
 sys/i386/i386/swtch.s        |  5 ++++-
 sys/i386/i386/vm_machdep.c   | 21 ++++++++++++++++++++-
 5 files changed, 52 insertions(+), 5 deletions(-)

diff --git a/sys/amd64/amd64/cpu_switch.S b/sys/amd64/amd64/cpu_switch.S
index e15298d6d046..db95daac6237 100644
--- a/sys/amd64/amd64/cpu_switch.S
+++ b/sys/amd64/amd64/cpu_switch.S
@@ -33,7 +33,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: swtch.s,v 1.19 1995/01/21 15:20:23 bde Exp $
+ *	$Id: swtch.s,v 1.20 1995/02/17 02:22:42 phk Exp $
  */
 
 #include "npx.h"	/* for NNPX */
@@ -278,6 +278,9 @@ idle_loop:
 	cmpl	$0,_whichidqs			/* 'idle' queue */
 	jne	idqr
 	movb	$0,_intr_nesting_level		/* charge Idle for this loop */
+	call	_vm_page_zero_idle
+	testl	%eax, %eax
+	jnz	idle_loop
 #if NAPM > 0
 #if APM_SLOWSTART <= 0 || !defined(APM_SLOWSTART)
 	/*
diff --git a/sys/amd64/amd64/swtch.s b/sys/amd64/amd64/swtch.s
index e15298d6d046..db95daac6237 100644
--- a/sys/amd64/amd64/swtch.s
+++ b/sys/amd64/amd64/swtch.s
@@ -33,7 +33,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: swtch.s,v 1.19 1995/01/21 15:20:23 bde Exp $
+ *	$Id: swtch.s,v 1.20 1995/02/17 02:22:42 phk Exp $
  */
 
 #include "npx.h"	/* for NNPX */
@@ -278,6 +278,9 @@ idle_loop:
 	cmpl	$0,_whichidqs			/* 'idle' queue */
 	jne	idqr
 	movb	$0,_intr_nesting_level		/* charge Idle for this loop */
+	call	_vm_page_zero_idle
+	testl	%eax, %eax
+	jnz	idle_loop
 #if NAPM > 0
 #if APM_SLOWSTART <= 0 || !defined(APM_SLOWSTART)
 	/*
diff --git a/sys/amd64/amd64/vm_machdep.c b/sys/amd64/amd64/vm_machdep.c
index 08dab5355036..debfe4a3ba71 100644
--- a/sys/amd64/amd64/vm_machdep.c
+++ b/sys/amd64/amd64/vm_machdep.c
@@ -38,7 +38,7 @@
  *
  *	from: @(#)vm_machdep.c	7.3 (Berkeley) 5/13/91
  *	Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$
- *	$Id: vm_machdep.c,v 1.40 1995/07/13 08:47:29 davidg Exp $
+ *	$Id: vm_machdep.c,v 1.41 1995/07/29 11:38:53 bde Exp $
  */
 
 #include "npx.h"
@@ -862,3 +862,22 @@ grow(p, sp)
 
 	return (1);
 }
+
+/*
+ * prototype routine to implement the pre-zeroed page mechanism
+ * this routine is called from the idle loop.
+ */
+int
+vm_page_zero_idle() {
+	vm_page_t m;
+	if ((cnt.v_free_count > cnt.v_interrupt_free_min) &&
+		(m = vm_page_queue_free.tqh_first)) {
+		TAILQ_REMOVE(&vm_page_queue_free, m, pageq);
+		enable_intr();
+		pmap_zero_page(VM_PAGE_TO_PHYS(m));
+		disable_intr();
+		TAILQ_INSERT_TAIL(&vm_page_queue_zero, m, pageq);
+		return 1;
+	}
+	return 0;
+}
diff --git a/sys/i386/i386/swtch.s b/sys/i386/i386/swtch.s
index e15298d6d046..db95daac6237 100644
--- a/sys/i386/i386/swtch.s
+++ b/sys/i386/i386/swtch.s
@@ -33,7 +33,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: swtch.s,v 1.19 1995/01/21 15:20:23 bde Exp $
+ *	$Id: swtch.s,v 1.20 1995/02/17 02:22:42 phk Exp $
  */
 
 #include "npx.h"	/* for NNPX */
@@ -278,6 +278,9 @@ idle_loop:
 	cmpl	$0,_whichidqs			/* 'idle' queue */
 	jne	idqr
 	movb	$0,_intr_nesting_level		/* charge Idle for this loop */
+	call	_vm_page_zero_idle
+	testl	%eax, %eax
+	jnz	idle_loop
 #if NAPM > 0
 #if APM_SLOWSTART <= 0 || !defined(APM_SLOWSTART)
 	/*
diff --git a/sys/i386/i386/vm_machdep.c b/sys/i386/i386/vm_machdep.c
index 08dab5355036..debfe4a3ba71 100644
--- a/sys/i386/i386/vm_machdep.c
+++ b/sys/i386/i386/vm_machdep.c
@@ -38,7 +38,7 @@
  *
  *	from: @(#)vm_machdep.c	7.3 (Berkeley) 5/13/91
  *	Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$
- *	$Id: vm_machdep.c,v 1.40 1995/07/13 08:47:29 davidg Exp $
+ *	$Id: vm_machdep.c,v 1.41 1995/07/29 11:38:53 bde Exp $
  */
 
 #include "npx.h"
@@ -862,3 +862,22 @@ grow(p, sp)
 
 	return (1);
 }
+
+/*
+ * prototype routine to implement the pre-zeroed page mechanism
+ * this routine is called from the idle loop.
+ */
+int
+vm_page_zero_idle() {
+	vm_page_t m;
+	if ((cnt.v_free_count > cnt.v_interrupt_free_min) &&
+		(m = vm_page_queue_free.tqh_first)) {
+		TAILQ_REMOVE(&vm_page_queue_free, m, pageq);
+		enable_intr();
+		pmap_zero_page(VM_PAGE_TO_PHYS(m));
+		disable_intr();
+		TAILQ_INSERT_TAIL(&vm_page_queue_zero, m, pageq);
+		return 1;
+	}
+	return 0;
+}