From the UBC branch and NetBSD.

We allocate map entries for the non-intrsafe kernel map (most notably
kernel_map and exec_map) from a pool that's backed by kmem_map (to avoid
deadlocking).

This should get rid of MAX_KMAPENT panics.

2 files changed, 33 insertions, 26 deletions

diff --git a/sys/uvm/uvm_map.c b/sys/uvm/uvm_map.c
index f30fae1c6da..4c02265a654 100644
--- a/sys/uvm/uvm_map.c
+++ b/sys/uvm/uvm_map.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_map.c,v 1.37 2002/01/23 00:39:48 art Exp $	*/
+/*	$OpenBSD: uvm_map.c,v 1.38 2002/02/18 10:02:20 art Exp $	*/
 /*	$NetBSD: uvm_map.c,v 1.86 2000/11/27 08:40:03 chs Exp $	*/
 
 /* 
@@ -77,6 +77,7 @@
 #include <sys/proc.h>
 #include <sys/malloc.h>
 #include <sys/pool.h>
+#include <sys/kernel.h>
 
 #ifdef SYSVSHM
 #include <sys/shm.h>
@@ -105,6 +106,7 @@ struct pool uvm_vmspace_pool;
  */
 
 struct pool uvm_map_entry_pool;
+struct pool uvm_map_entry_kmem_pool;
 
 #ifdef PMAP_GROWKERNEL
 /*
@@ -189,39 +191,39 @@ static void		uvm_map_unreference_amap __P((vm_map_entry_t, int));
 
 /*
  * uvm_mapent_alloc: allocate a map entry
- *
- * => XXX: static pool for kernel map?
  */
 
 static __inline vm_map_entry_t
 uvm_mapent_alloc(map)
 	vm_map_t map;
 {
-	vm_map_entry_t me;
+	struct vm_map_entry *me;
 	int s;
-	UVMHIST_FUNC("uvm_mapent_alloc");
-	UVMHIST_CALLED(maphist);
+	UVMHIST_FUNC("uvm_mapent_alloc"); UVMHIST_CALLED(maphist);
 
-	if ((map->flags & VM_MAP_INTRSAFE) == 0 &&
-	    map != kernel_map && kernel_map != NULL /* XXX */) {
-		me = pool_get(&uvm_map_entry_pool, PR_WAITOK);
-		me->flags = 0;
-		/* me can't be null, wait ok */
-	} else {
-		s = splvm();	/* protect kentry_free list with splvm */
+	if (map->flags & VM_MAP_INTRSAFE || cold) {
+		s = splvm();
 		simple_lock(&uvm.kentry_lock);
 		me = uvm.kentry_free;
 		if (me) uvm.kentry_free = me->next;
 		simple_unlock(&uvm.kentry_lock);
 		splx(s);
-		if (!me)
-	panic("mapent_alloc: out of static map entries, check MAX_KMAPENT");
+		if (me == NULL) {
+			panic("uvm_mapent_alloc: out of static map entries, "
+			      "check MAX_KMAPENT (currently %d)",
+			      MAX_KMAPENT);
+		}
 		me->flags = UVM_MAP_STATIC;
+	} else if (map == kernel_map) {
+		me = pool_get(&uvm_map_entry_kmem_pool, PR_WAITOK);
+		me->flags = UVM_MAP_KMEM;
+	} else {
+		me = pool_get(&uvm_map_entry_pool, PR_WAITOK);
+		me->flags = 0;
 	}
 
-	UVMHIST_LOG(maphist, "<- new entry=0x%x [kentry=%d]", 
-		me, ((map->flags & VM_MAP_INTRSAFE) != 0 || map == kernel_map)
-		? TRUE : FALSE, 0, 0);
+	UVMHIST_LOG(maphist, "<- new entry=0x%x [kentry=%d]", me,
+	    ((map->flags & VM_MAP_INTRSAFE) != 0 || map == kernel_map), 0, 0);
 	return(me);
 }
 
@@ -236,19 +238,21 @@ uvm_mapent_free(me)
 	vm_map_entry_t me;
 {
 	int s;
-	UVMHIST_FUNC("uvm_mapent_free");
-	UVMHIST_CALLED(maphist);
-	UVMHIST_LOG(maphist,"<- freeing map entry=0x%x [flags=%d]", 
+	UVMHIST_FUNC("uvm_mapent_free"); UVMHIST_CALLED(maphist);
+
+	UVMHIST_LOG(maphist,"<- freeing map entry=0x%x [flags=%d]",
 		me, me->flags, 0, 0);
-	if ((me->flags & UVM_MAP_STATIC) == 0) {
-		pool_put(&uvm_map_entry_pool, me);
-	} else {
-		s = splvm();	/* protect kentry_free list with splvm */
+	if (me->flags & UVM_MAP_STATIC) {
+		s = splvm();
 		simple_lock(&uvm.kentry_lock);
 		me->next = uvm.kentry_free;
 		uvm.kentry_free = me;
 		simple_unlock(&uvm.kentry_lock);
 		splx(s);
+	} else if (me->flags & UVM_MAP_KMEM) {
+		pool_put(&uvm_map_entry_kmem_pool, me);
+	} else {
+		pool_put(&uvm_map_entry_pool, me);
 	}
 }
 
@@ -358,6 +362,8 @@ uvm_map_init()
 	    0, 0, 0, "vmsppl", &pool_allocator_nointr);
 	pool_init(&uvm_map_entry_pool, sizeof(struct vm_map_entry),
 	    0, 0, 0, "vmmpepl", &pool_allocator_nointr);
+	pool_init(&uvm_map_entry_kmem_pool, sizeof(struct vm_map_entry),
+	    0, 0, 0, "vmmpekpl", NULL);
 }
 
 /*
diff --git a/sys/uvm/uvm_map.h b/sys/uvm/uvm_map.h
index 724bd78ab23..ad865ece22b 100644
--- a/sys/uvm/uvm_map.h
+++ b/sys/uvm/uvm_map.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_map.h,v 1.20 2001/12/19 08:58:07 art Exp $	*/
+/*	$OpenBSD: uvm_map.h,v 1.21 2002/02/18 10:02:20 art Exp $	*/
 /*	$NetBSD: uvm_map.h,v 1.24 2001/02/18 21:19:08 chs Exp $	*/
 
 /* 
@@ -156,6 +156,7 @@ struct vm_map_entry {
 	u_int8_t		flags;		/* flags */
 
 #define UVM_MAP_STATIC		0x01		/* static map entry */
+#define UVM_MAP_KMEM		0x02		/* from kmem entry pool */
 
 };