From: Martin Pieuchot <mpi@grenadille.net>
Subject: fail earlier in pgo_get
To: tech@openbsd.org
Date: Mon, 27 Oct 2025 10:34:45 +0100

Stop iterating as soon as a page is missing or busy when all pages are
asked by the caller.

Note that currently pgo_get() is not called with PGO_ALLPAGES in the
kernel.  This is a requirement for upcoming changes.

ok?

Index: uvm/uvm_aobj.c
===================================================================
RCS file: /cvs/src/sys/uvm/uvm_aobj.c,v
diff -u -p -r1.116 uvm_aobj.c
--- uvm/uvm_aobj.c	10 Mar 2025 14:13:58 -0000	1.116
+++ uvm/uvm_aobj.c	27 Oct 2025 09:31:40 -0000
@@ -1024,10 +1024,13 @@ uao_get(struct uvm_object *uobj, voff_t 
 			 * to be useful must get a non-busy page
 			 */
 			if (ptmp == NULL || (ptmp->pg_flags & PG_BUSY) != 0) {
-				if (lcv == centeridx ||
-				    (flags & PGO_ALLPAGES) != 0)
+				if (lcv == centeridx)
 					/* need to do a wait or I/O! */
 					done = FALSE;
+				if ((flags & PGO_ALLPAGES) != 0) {
+					done = FALSE;
+					break;
+				}
 				continue;
 			}
 
Index: uvm/uvm_vnode.c
===================================================================
RCS file: /cvs/src/sys/uvm/uvm_vnode.c,v
diff -u -p -r1.142 uvm_vnode.c
--- uvm/uvm_vnode.c	29 Sep 2025 09:55:01 -0000	1.142
+++ uvm/uvm_vnode.c	27 Oct 2025 09:32:09 -0000
@@ -977,10 +990,13 @@ uvn_get(struct uvm_object *uobj, voff_t 
 			 * to be useful must get a non-busy page
 			 */
 			if (ptmp == NULL || (ptmp->pg_flags & PG_BUSY) != 0) {
-				if (lcv == centeridx ||
-				    (flags & PGO_ALLPAGES) != 0)
+				if (lcv == centeridx)
 					/* need to do a wait or I/O! */
 					done = FALSE;
+				if ((flags & PGO_ALLPAGES) != 0) {
+					done = FALSE;
+					break;
+				}
 				continue;
 			}