[src/trunk]: src/sys/uvm uvmpdpol_selectvictim: don't assert wire_count == 0,...

[ad <ad%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/d142322aa203
branches:  trunk
changeset: 967843:d142322aa203
user:      ad <ad%NetBSD.org@localhost>
date:      Mon Dec 23 19:29:03 2019 +0000

description:
uvmpdpol_selectvictim: don't assert wire_count == 0, as we can (safely)
race with object owner and wired pages can very briefly appear on the queue.

diffstat:

 sys/uvm/uvm_pdpolicy_clock.c |  6 ++----
 1 files changed, 2 insertions(+), 4 deletions(-)

diffs (27 lines):

diff -r fd035f428d15 -r d142322aa203 sys/uvm/uvm_pdpolicy_clock.c
--- a/sys/uvm/uvm_pdpolicy_clock.c      Mon Dec 23 19:28:04 2019 +0000
+++ b/sys/uvm/uvm_pdpolicy_clock.c      Mon Dec 23 19:29:03 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uvm_pdpolicy_clock.c,v 1.21 2019/12/21 13:00:25 ad Exp $       */
+/*     $NetBSD: uvm_pdpolicy_clock.c,v 1.22 2019/12/23 19:29:03 ad Exp $       */
 /*     NetBSD: uvm_pdaemon.c,v 1.72 2006/01/05 10:47:33 yamt Exp $     */
 
 /*
@@ -69,7 +69,7 @@
 #else /* defined(PDSIM) */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_pdpolicy_clock.c,v 1.21 2019/12/21 13:00:25 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_pdpolicy_clock.c,v 1.22 2019/12/23 19:29:03 ad Exp $");
 
 #include <sys/param.h>
 #include <sys/proc.h>
@@ -208,8 +208,6 @@
                        break;
                }
                ss->ss_nextpg = TAILQ_NEXT(pg, pageq.queue);
-               KASSERT(pg->wire_count == 0);
-
                uvmexp.pdscans++;
 
                /*