[src/trunk]: src/sys/uvm Enable ubc_direct by default, but only on systems wi...

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

details:   https://anonhg.NetBSD.org/src/rev/dafe3bed6f9a
branches:  trunk
changeset: 1009465:dafe3bed6f9a
user:      ad <ad%NetBSD.org@localhost>
date:      Thu Apr 23 21:53:01 2020 +0000

description:
Enable ubc_direct by default, but only on systems with no more than 2 CPUs
for now.

diffstat:

 sys/uvm/uvm_bio.c  |   6 +++---
 sys/uvm/uvm_glue.c |  16 ++++++++++++++--
 2 files changed, 17 insertions(+), 5 deletions(-)

diffs (64 lines):

diff -r 9174fac0875d -r dafe3bed6f9a sys/uvm/uvm_bio.c
--- a/sys/uvm/uvm_bio.c Thu Apr 23 21:47:07 2020 +0000
+++ b/sys/uvm/uvm_bio.c Thu Apr 23 21:53:01 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uvm_bio.c,v 1.110 2020/04/23 21:47:09 ad Exp $ */
+/*     $NetBSD: uvm_bio.c,v 1.111 2020/04/23 21:53:01 ad Exp $ */
 
 /*
  * Copyright (c) 1998 Chuck Silvers.
@@ -34,7 +34,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_bio.c,v 1.110 2020/04/23 21:47:09 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_bio.c,v 1.111 2020/04/23 21:53:01 ad Exp $");
 
 #include "opt_uvmhist.h"
 #include "opt_ubc.h"
@@ -64,7 +64,7 @@
                          int, int);
 static void __noinline ubc_zerorange_direct(struct uvm_object *, off_t, size_t, int);
 
-bool ubc_direct = false; /* XXX */
+bool ubc_direct = true;
 #endif
 
 /*
diff -r 9174fac0875d -r dafe3bed6f9a sys/uvm/uvm_glue.c
--- a/sys/uvm/uvm_glue.c        Thu Apr 23 21:47:07 2020 +0000
+++ b/sys/uvm/uvm_glue.c        Thu Apr 23 21:53:01 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uvm_glue.c,v 1.177 2020/03/05 12:21:00 rin Exp $       */
+/*     $NetBSD: uvm_glue.c,v 1.178 2020/04/23 21:53:01 ad Exp $        */
 
 /*
  * Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -62,7 +62,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_glue.c,v 1.177 2020/03/05 12:21:00 rin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_glue.c,v 1.178 2020/04/23 21:53:01 ad Exp $");
 
 #include "opt_kgdb.h"
 #include "opt_kstack.h"
@@ -504,6 +504,18 @@
        /* Start the freelist cache. */
        uvm_pgflcache_start();
 
+#ifdef PMAP_DIRECT
+       /*
+        * XXX Temporary ugly hack.  Just before boot, disable ubc_direct if
+        * there's more than a couple of CPUs, since it has concurrency
+        * problems.
+        */
+       if (ncpu > 2) {
+               extern bool ubc_direct;
+               ubc_direct = false;
+       }
+#endif
+
        for (;;) {
                /* Update legacy stats for post-mortem debugging. */
                uvm_update_uvmexp();