From b3a01bdf1f114c3ccd66f8c267c319908965ad2d Mon Sep 17 00:00:00 2001
From: Andrey Zonov <zont@FreeBSD.org>
Date: Mon, 28 Jan 2013 12:54:53 +0000
Subject: [PATCH] - Add system wide page faults requiring I/O counter.

Reviewed by:	alc
MFC after:	2 weeks
---
 sys/sys/vmmeter.h | 1 +
 sys/vm/vm_fault.c | 5 +++--
 sys/vm/vm_meter.c | 1 +
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/sys/sys/vmmeter.h b/sys/sys/vmmeter.h
index 1a29ec185382..59b430d53206 100644
--- a/sys/sys/vmmeter.h
+++ b/sys/sys/vmmeter.h
@@ -61,6 +61,7 @@ struct vmmeter {
 	 * Virtual memory activity.
 	 */
 	u_int v_vm_faults;	/* (p) address memory faults */
+	u_int v_io_faults;	/* (p) page faults requiring I/O */
 	u_int v_cow_faults;	/* (p) copy-on-writes faults */
 	u_int v_cow_optim;	/* (p) optimized copy-on-writes faults */
 	u_int v_zfod;		/* (p) pages zero filled on demand */
diff --git a/sys/vm/vm_fault.c b/sys/vm/vm_fault.c
index 6865782a5eac..b79b3f5e7b78 100644
--- a/sys/vm/vm_fault.c
+++ b/sys/vm/vm_fault.c
@@ -939,9 +939,10 @@ RetryFault:;
 	 * Unlock everything, and return
 	 */
 	unlock_and_deallocate(&fs);
-	if (hardfault)
+	if (hardfault) {
+		PCPU_INC(cnt.v_io_faults);
 		curthread->td_ru.ru_majflt++;
-	else
+	} else 
 		curthread->td_ru.ru_minflt++;
 
 	return (KERN_SUCCESS);
diff --git a/sys/vm/vm_meter.c b/sys/vm/vm_meter.c
index b5bb0fa9580a..05174e987867 100644
--- a/sys/vm/vm_meter.c
+++ b/sys/vm/vm_meter.c
@@ -283,6 +283,7 @@ VM_STATS_SYS(v_syscall, "System calls");
 VM_STATS_SYS(v_intr, "Device interrupts");
 VM_STATS_SYS(v_soft, "Software interrupts");
 VM_STATS_VM(v_vm_faults, "Address memory faults");
+VM_STATS_VM(v_io_faults, "Page faults requiring I/O");
 VM_STATS_VM(v_cow_faults, "Copy-on-write faults");
 VM_STATS_VM(v_cow_optim, "Optimized COW faults");
 VM_STATS_VM(v_zfod, "Pages zero-filled on demand");