From ca737cbec5c16debd771700a0451a5f19b06f5be Mon Sep 17 00:00:00 2001
From: Bill Joy <wnj@ucbvax.Berkeley.EDU>
Date: Sun, 1 Mar 1981 02:01:33 -0800
Subject: [PATCH 1/1] fixups for rm* routines

SCCS-vsn: sys/sys/map.h 4.5
SCCS-vsn: sys/sys/systm.h 4.13
---
 usr/src/sys/sys/map.h   | 36 +++++++++++++++++++++++++++++++-----
 usr/src/sys/sys/systm.h |  3 ++-
 2 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/usr/src/sys/sys/map.h b/usr/src/sys/sys/map.h
index 9251c5f054..dffed9feff 100644
--- a/usr/src/sys/sys/map.h
+++ b/usr/src/sys/sys/map.h
@@ -1,17 +1,43 @@
-/*	map.h	4.4	81/02/27	*/
+/*	map.h	4.5	81/02/28	*/
 
 /*
- * Resource Allocation Maps
+ * Resource Allocation Maps.
+ *
+ * Associated routines manage sub-allocation of an address space using
+ * an array of segment descriptors.  The first element of this array
+ * is a map structure, describing the arrays extent and the name
+ * of the controlled object.  Each additional structure represents
+ * a free segment of the address space.
+ *
+ * A call to rminit initializes a resource map and may also be used
+ * to free some address space for the map.  Subsequent calls to rmalloc
+ * and rmfree allocate and free space in the resource map.  If the resource
+ * map becomes too fragmented to be described in the available space,
+ * then some of the resource is discarded.  This may lead to critical
+ * shortages, but is better than not checking (as the previous versions
+ * of these routines did) or giving up and calling panic().  The routines
+ * could use linked lists and call a memory allocator when they run
+ * out of space, but that would not solve the out of space problem when
+ * called at interrupt time.
+ *
+ * N.B.: The address 0 in the resource address space is not available
+ * as it is used internally by the resource map routines.
  */
-struct map
+struct map {
+	struct	mapent *m_limit;	/* address of last slot in map */
+	char	*m_name;		/* name of resource */
+/* we use m_name when the map overflows, in warning messages */
+};
+struct mapent
 {
-	int	m_size;
-	int	m_addr;
+	int	m_size;		/* size of this segment of the map */
+	int	m_addr;		/* resource-space addr of start of segment */
 };
 
 #ifdef KERNEL
 struct	map *swapmap;
 int	nswapmap;
 struct	map *argmap;
+#define	ARGMAPSIZE	16
 struct	map *kernelmap;
 #endif
diff --git a/usr/src/sys/sys/systm.h b/usr/src/sys/sys/systm.h
index 6c767ef03b..87b0fc9e80 100644
--- a/usr/src/sys/sys/systm.h
+++ b/usr/src/sys/sys/systm.h
@@ -1,4 +1,4 @@
-/*	systm.h	4.12	81/02/27	*/
+/*	systm.h	4.13	81/02/28	*/
 
 /*
  * Random set of variables
@@ -83,3 +83,4 @@ char	vmmap[];		/* poor name! */
 int	umbabeg,umbaend;	/* where sensitive vm begins/ends */
 int	noproc;			/* no one is running just now */
 extern	int catcher[256];
+char	*panicstr;
-- 
2.20.1