From e461aae747ef3815eb2bd016169d17eb611f8328 Mon Sep 17 00:00:00 2001
From: Konstantin Belousov <kib@FreeBSD.org>
Date: Sat, 12 May 2012 20:34:22 +0000
Subject: [PATCH] Split the code from vm_page_getfake() to initialize the fake
 page struct vm_page into new interface vm_page_initfake(). Handle the case of
 fake page re-initialization with changed memattr.

Sponsored by:	The FreeBSD Foundation
Reviewed by:	alc
MFC after:	1 month
---
 sys/vm/vm_page.c | 18 +++++++++++++++++-
 sys/vm/vm_page.h |  1 +
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c
index bd004fb467f..832ab7eea93 100644
--- a/sys/vm/vm_page.c
+++ b/sys/vm/vm_page.c
@@ -646,6 +646,22 @@ vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr)
 	vm_page_t m;
 
 	m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO);
+	vm_page_initfake(m, paddr, memattr);
+	return (m);
+}
+
+void
+vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr)
+{
+
+	if ((m->flags & PG_FICTITIOUS) != 0) {
+		/*
+		 * The page's memattr might have changed since the
+		 * previous initialization.  Update the pmap to the
+		 * new memattr.
+		 */
+		goto memattr;
+	}
 	m->phys_addr = paddr;
 	m->queue = PQ_NONE;
 	/* Fictitious pages don't use "segind". */
@@ -653,8 +669,8 @@ vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr)
 	/* Fictitious pages don't use "order" or "pool". */
 	m->oflags = VPO_BUSY | VPO_UNMANAGED;
 	m->wire_count = 1;
+memattr:
 	pmap_page_set_memattr(m, memattr);
-	return (m);
 }
 
 /*
diff --git a/sys/vm/vm_page.h b/sys/vm/vm_page.h
index 2d2a1bcae9f..cad8c03488a 100644
--- a/sys/vm/vm_page.h
+++ b/sys/vm/vm_page.h
@@ -391,6 +391,7 @@ void vm_page_dontneed(vm_page_t);
 void vm_page_deactivate (vm_page_t);
 vm_page_t vm_page_find_least(vm_object_t, vm_pindex_t);
 vm_page_t vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr);
+void vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr);
 void vm_page_insert (vm_page_t, vm_object_t, vm_pindex_t);
 boolean_t vm_page_is_cached(vm_object_t object, vm_pindex_t pindex);
 vm_page_t vm_page_lookup (vm_object_t, vm_pindex_t);