From 6f0489c670b961d3de0d21aee144e5bd1d44c5f1 Mon Sep 17 00:00:00 2001
From: Alan Cox <alc@FreeBSD.org>
Date: Sun, 21 Jun 2009 00:21:33 +0000
Subject: [PATCH] Strive for greater consistency among the places that
 implement real, fictious, and contiguous page allocation.  Eliminate
 unnecessary reinitialization of a page's fields.

---
 sys/vm/device_pager.c |  1 +
 sys/vm/vm_page.c      | 17 ++++++++---------
 sys/vm/vm_phys.c      | 13 +++++++++----
 3 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/sys/vm/device_pager.c b/sys/vm/device_pager.c
index 5e31e2b1900f..5472d64cc559 100644
--- a/sys/vm/device_pager.c
+++ b/sys/vm/device_pager.c
@@ -307,6 +307,7 @@ dev_pager_getfake(paddr)
 
 	m->flags = PG_FICTITIOUS;
 	m->oflags = VPO_BUSY;
+	/* Fictitious pages don't use "act_count". */
 	m->valid = VM_PAGE_BITS_ALL;
 	m->dirty = 0;
 	m->busy = 0;
diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c
index 370aea0f74f7..7148fdc0b760 100644
--- a/sys/vm/vm_page.c
+++ b/sys/vm/vm_page.c
@@ -1108,10 +1108,13 @@ vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req)
 	 *  At this point we had better have found a good page.
 	 */
 
-	KASSERT(
-	    m != NULL,
-	    ("vm_page_alloc(): missing page on free queue")
-	);
+	KASSERT(m != NULL, ("vm_page_alloc: missing page"));
+	KASSERT(m->queue == PQ_NONE, ("vm_page_alloc: page %p has unexpected queue %d",
+	    m, m->queue));
+	KASSERT(m->wire_count == 0, ("vm_page_alloc: page %p is wired", m));
+	KASSERT(m->hold_count == 0, ("vm_page_alloc: page %p is held", m));
+	KASSERT(m->busy == 0, ("vm_page_alloc: page %p is busy", m));
+	KASSERT(m->dirty == 0, ("vm_page_alloc: page %p is dirty", m));
 	if ((m->flags & PG_CACHED) != 0) {
 		KASSERT(m->valid != 0,
 		    ("vm_page_alloc: cached page %p is invalid", m));
@@ -1150,12 +1153,8 @@ vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req)
 	if (req & VM_ALLOC_WIRED) {
 		atomic_add_int(&cnt.v_wire_count, 1);
 		m->wire_count = 1;
-	} else
-		m->wire_count = 0;
-	m->hold_count = 0;
+	}
 	m->act_count = 0;
-	m->busy = 0;
-	KASSERT(m->dirty == 0, ("vm_page_alloc: free/cache page %p was dirty", m));
 	mtx_unlock(&vm_page_queue_free_mtx);
 
 	if ((req & VM_ALLOC_NOOBJ) == 0)
diff --git a/sys/vm/vm_phys.c b/sys/vm/vm_phys.c
index b6d1cb3e1e49..0de35cd75dc9 100644
--- a/sys/vm/vm_phys.c
+++ b/sys/vm/vm_phys.c
@@ -689,6 +689,14 @@ vm_phys_alloc_contig(unsigned long npages, vm_paddr_t low, vm_paddr_t high,
 		KASSERT(m->queue == PQ_NONE,
 		    ("vm_phys_alloc_contig: page %p has unexpected queue %d",
 		    m, m->queue));
+		KASSERT(m->wire_count == 0,
+		    ("vm_phys_alloc_contig: page %p is wired", m));
+		KASSERT(m->hold_count == 0,
+		    ("vm_phys_alloc_contig: page %p is held", m));
+		KASSERT(m->busy == 0,
+		    ("vm_phys_alloc_contig: page %p is busy", m));
+		KASSERT(m->dirty == 0,
+		    ("vm_phys_alloc_contig: page %p is dirty", m));
 		m_object = m->object;
 		if ((m->flags & PG_CACHED) != 0) {
 			m->valid = 0;
@@ -705,10 +713,7 @@ vm_phys_alloc_contig(unsigned long npages, vm_paddr_t low, vm_paddr_t high,
 		/* Don't clear the PG_ZERO flag; we'll need it later. */
 		m->flags = PG_UNMANAGED | (m->flags & PG_ZERO);
 		m->oflags = 0;
-		KASSERT(m->dirty == 0,
-		    ("vm_phys_alloc_contig: page %p was dirty", m));
-		m->wire_count = 0;
-		m->busy = 0;
+		/* Unmanaged pages don't use "act_count". */
 		if (m_object != NULL &&
 		    m_object->type == OBJT_VNODE &&
 		    m_object->cache == NULL) {