From dca400e253df97804dd04b24e96aebba878781a0 Mon Sep 17 00:00:00 2001
From: Justus Winter <4winter@informatik.uni-hamburg.de>
Date: Wed, 30 Apr 2014 15:23:36 +0200
Subject: vm: make struct vm_map fit into a cache line

Currently, the size of struct vm_map is 68 bytes.  By using a bit
field for the boolean flags, it can be made fit into a cache line.

* vm/vm_map.h (struct vm_map): Use a bit field for the boolean flags
wait_for_space and wiring_required.
---
 vm/vm_map.h | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

(limited to 'vm/vm_map.h')

diff --git a/vm/vm_map.h b/vm/vm_map.h
index b6bc177..b8103eb 100644
--- a/vm/vm_map.h
+++ b/vm/vm_map.h
@@ -175,9 +175,12 @@ struct vm_map {
 	vm_map_entry_t		hint;		/* hint for quick lookups */
 	decl_simple_lock_data(,	hint_lock)	/* lock for hint storage */
 	vm_map_entry_t		first_free;	/* First free space hint */
-	boolean_t		wait_for_space;	/* Should callers wait
+
+	/* Flags */
+	unsigned int	wait_for_space:1,	/* Should callers wait
 						   for space? */
-	boolean_t		wiring_required;/* All memory wired? */
+	/* boolean_t */ wiring_required:1;	/* All memory wired? */
+
 	unsigned int		timestamp;	/* Version number */
 };
 
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