add a param to uvm_map_hint to not skip over the heap, and use it as a last

resort if mmap fails otherwise to enable more complete address space
utilization.  tested for a while with no ill effects.

3 files changed, 16 insertions, 6 deletions

diff --git a/sys/uvm/uvm_map.c b/sys/uvm/uvm_map.c
index 53aa5c4fe7c..91d5db39e64 100644
--- a/sys/uvm/uvm_map.c
+++ b/sys/uvm/uvm_map.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_map.c,v 1.130 2010/12/15 04:59:52 tedu Exp $	*/
+/*	$OpenBSD: uvm_map.c,v 1.131 2010/12/24 21:49:04 tedu Exp $	*/
 /*	$NetBSD: uvm_map.c,v 1.86 2000/11/27 08:40:03 chs Exp $	*/
 
 /* 
@@ -1241,7 +1241,7 @@ uvm_map_pie(vaddr_t align)
  * creating a new mapping with "prot" protection.
  */
 vaddr_t
-uvm_map_hint(struct proc *p, vm_prot_t prot)
+uvm_map_hint1(struct proc *p, vm_prot_t prot, int skipheap)
 {
 	vaddr_t addr;
 
@@ -1258,7 +1258,9 @@ uvm_map_hint(struct proc *p, vm_prot_t prot)
 	}
 #endif
 	/* start malloc/mmap after the brk */
-	addr = (vaddr_t)p->p_vmspace->vm_daddr + BRKSIZ;
+	addr = (vaddr_t)p->p_vmspace->vm_daddr;
+	if (skipheap)
+		addr += BRKSIZ;
 #if !defined(__vax__)
 	addr += arc4random() & (MIN((256 * 1024 * 1024), BRKSIZ) - 1);
 #endif
diff --git a/sys/uvm/uvm_map.h b/sys/uvm/uvm_map.h
index 0838713311b..0c05d491289 100644
--- a/sys/uvm/uvm_map.h
+++ b/sys/uvm/uvm_map.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_map.h,v 1.43 2010/04/20 22:05:44 tedu Exp $	*/
+/*	$OpenBSD: uvm_map.h,v 1.44 2010/12/24 21:49:04 tedu Exp $	*/
 /*	$NetBSD: uvm_map.h,v 1.24 2001/02/18 21:19:08 chs Exp $	*/
 
 /* 
@@ -287,7 +287,8 @@ int		uvm_map_extract(vm_map_t, vaddr_t, vsize_t,
 vm_map_entry_t	uvm_map_findspace(vm_map_t, vaddr_t, vsize_t, vaddr_t *,
 		    struct uvm_object *, voff_t, vsize_t, int);
 vaddr_t		uvm_map_pie(vaddr_t);
-vaddr_t		uvm_map_hint(struct proc *, vm_prot_t);
+#define		uvm_map_hint(p, prot) uvm_map_hint1(p, prot, 1)
+vaddr_t		uvm_map_hint1(struct proc *, vm_prot_t, int);
 int		uvm_map_inherit(vm_map_t, vaddr_t, vaddr_t, vm_inherit_t);
 int		uvm_map_advice(vm_map_t, vaddr_t, vaddr_t, int);
 void		uvm_map_init(void);
diff --git a/sys/uvm/uvm_mmap.c b/sys/uvm/uvm_mmap.c
index 4e606dbf8ae..4ae8c3d3797 100644
--- a/sys/uvm/uvm_mmap.c
+++ b/sys/uvm/uvm_mmap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_mmap.c,v 1.81 2010/12/15 04:59:53 tedu Exp $	*/
+/*	$OpenBSD: uvm_mmap.c,v 1.82 2010/12/24 21:49:04 tedu Exp $	*/
 /*	$NetBSD: uvm_mmap.c,v 1.49 2001/02/18 21:19:08 chs Exp $	*/
 
 /*
@@ -604,6 +604,13 @@ sys_mmap(struct proc *p, void *v, register_t *retval)
 
 	error = uvm_mmap(&p->p_vmspace->vm_map, &addr, size, prot, maxprot,
 	    flags, handle, pos, p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur, p);
+	if (error == ENOMEM && !(flags & (MAP_FIXED | MAP_TRYFIXED))) {
+		/* once more, with feeling */
+		addr = uvm_map_hint1(p, prot, 0);
+		error = uvm_mmap(&p->p_vmspace->vm_map, &addr, size, prot,
+		    maxprot, flags, handle, pos,
+		    p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur, p);
+	}
 
 	if (error == 0)
 		/* remember to add offset */