some machines don't boot with the previous uvm reserve enforcement diff.

back it out.

1 files changed, 34 insertions, 6 deletions

diff --git a/sys/uvm/uvm_page.c b/sys/uvm/uvm_page.c
index 318a0e52734..6d44a95b6aa 100644
--- a/sys/uvm/uvm_page.c
+++ b/sys/uvm/uvm_page.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_page.c,v 1.113 2011/07/07 20:52:50 oga Exp $	*/
+/*	$OpenBSD: uvm_page.c,v 1.114 2011/07/08 00:10:59 tedu Exp $	*/
 /*	$NetBSD: uvm_page.c,v 1.44 2000/11/27 08:40:04 chs Exp $	*/
 
 /*
@@ -76,6 +76,7 @@
 #include <sys/sched.h>
 #include <sys/kernel.h>
 #include <sys/vnode.h>
+#include <sys/mount.h>
 #include <sys/proc.h>
 
 #include <uvm/uvm.h>
@@ -919,19 +920,43 @@ uvm_pagealloc(struct uvm_object *obj, voff_t off, struct vm_anon *anon,
 	struct vm_page *pg;
 	struct pglist pgl;
 	int pmr_flags;
+	boolean_t use_reserve;
 
 	KASSERT(obj == NULL || anon == NULL);
 	KASSERT(off == trunc_page(off));
 
-	/* XXX these functions should share flags */
+	/*
+	 * check to see if we need to generate some free pages waking
+	 * the pagedaemon.
+	 */
+	if ((uvmexp.free - BUFPAGES_DEFICIT) < uvmexp.freemin ||
+	    ((uvmexp.free - BUFPAGES_DEFICIT) < uvmexp.freetarg &&
+	    (uvmexp.inactive + BUFPAGES_INACT) < uvmexp.inactarg))
+		wakeup(&uvm.pagedaemon);
+
+	/*
+	 * fail if any of these conditions is true:
+	 * [1]  there really are no free pages, or
+	 * [2]  only kernel "reserved" pages remain and
+	 *        the page isn't being allocated to a kernel object.
+	 * [3]  only pagedaemon "reserved" pages remain and
+	 *        the requestor isn't the pagedaemon.
+	 */
+
+	use_reserve = (flags & UVM_PGA_USERESERVE) ||
+		(obj && UVM_OBJ_IS_KERN_OBJECT(obj));
+	if ((uvmexp.free <= uvmexp.reserve_kernel && !use_reserve) ||
+	    (uvmexp.free <= uvmexp.reserve_pagedaemon &&
+	     !((curproc == uvm.pagedaemon_proc) ||
+	      (curproc == syncerproc))))
+		goto fail;
+
 	pmr_flags = UVM_PLA_NOWAIT;
 	if (flags & UVM_PGA_ZERO)
 		pmr_flags |= UVM_PLA_ZERO;
-	if (flags & UVM_PGA_USERESERVE)
-		pmr_flags |= UVM_PLA_USERESERVE;
 	TAILQ_INIT(&pgl);
 	if (uvm_pmr_getpages(1, 0, 0, 1, 0, 1, pmr_flags, &pgl) != 0)
-		return (NULL);
+		goto fail;
 
 	pg = TAILQ_FIRST(&pgl);
 	KASSERT(pg != NULL && TAILQ_NEXT(pg, pageq) == NULL);
@@ -942,7 +967,10 @@ uvm_pagealloc(struct uvm_object *obj, voff_t off, struct vm_anon *anon,
 	if (flags & UVM_PGA_ZERO)
 		atomic_clearbits_int(&pg->pg_flags, PG_CLEAN);
 
-	return (pg);
+	return(pg);
+
+ fail:
+	return (NULL);
 }
 
 /*