[src/yamt-pagecache]: src/sys/uvm create a sysctl knob to turn on/off loaned ...

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

details:   https://anonhg.NetBSD.org/src/rev/f866e864b47b
branches:  yamt-pagecache
changeset: 770858:f866e864b47b
user:      yamt <yamt%NetBSD.org@localhost>
date:      Wed Jan 11 00:08:40 2012 +0000

description:
create a sysctl knob to turn on/off loaned read.

diffstat:

 sys/uvm/uvm_extern.h |   4 +++-
 sys/uvm/uvm_loan.c   |   8 ++++----
 sys/uvm/uvm_meter.c  |  10 ++++++++--
 3 files changed, 15 insertions(+), 7 deletions(-)

diffs (85 lines):

diff -r 70541da42d2e -r f866e864b47b sys/uvm/uvm_extern.h
--- a/sys/uvm/uvm_extern.h      Wed Jan 04 16:43:37 2012 +0000
+++ b/sys/uvm/uvm_extern.h      Wed Jan 11 00:08:40 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uvm_extern.h,v 1.176.2.6 2011/12/26 16:03:10 yamt Exp $        */
+/*     $NetBSD: uvm_extern.h,v 1.176.2.7 2012/01/11 00:08:40 yamt Exp $        */
 
 /*
  * Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -504,6 +504,8 @@
 extern struct uvmexp uvmexp;
 /* MD code needs this without including <uvm/uvm.h> */
 extern bool vm_page_zero_enable;
+
+extern bool vm_loan_read;
 #endif
 
 /*
diff -r 70541da42d2e -r f866e864b47b sys/uvm/uvm_loan.c
--- a/sys/uvm/uvm_loan.c        Wed Jan 04 16:43:37 2012 +0000
+++ b/sys/uvm/uvm_loan.c        Wed Jan 11 00:08:40 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uvm_loan.c,v 1.81.2.9 2012/01/04 16:31:17 yamt Exp $   */
+/*     $NetBSD: uvm_loan.c,v 1.81.2.10 2012/01/11 00:08:41 yamt Exp $  */
 
 /*
  * Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -32,7 +32,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_loan.c,v 1.81.2.9 2012/01/04 16:31:17 yamt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_loan.c,v 1.81.2.10 2012/01/11 00:08:41 yamt Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -42,7 +42,7 @@
 
 #include <uvm/uvm.h>
 
-bool doloanobj = true;
+bool vm_loan_read = true;
 
 /*
  * "loaned" pages are pages which are (read-only, copy-on-write) loaned
@@ -1304,7 +1304,7 @@
        size_t len;
        int i, error = 0;
 
-       if (!doloanobj) {
+       if (!vm_loan_read) {
                return ENOSYS;
        }
 
diff -r 70541da42d2e -r f866e864b47b sys/uvm/uvm_meter.c
--- a/sys/uvm/uvm_meter.c       Wed Jan 04 16:43:37 2012 +0000
+++ b/sys/uvm/uvm_meter.c       Wed Jan 11 00:08:40 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uvm_meter.c,v 1.56.4.6 2011/12/26 16:03:11 yamt Exp $  */
+/*     $NetBSD: uvm_meter.c,v 1.56.4.7 2012/01/11 00:08:41 yamt Exp $  */
 
 /*
  * Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -36,7 +36,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_meter.c,v 1.56.4.6 2011/12/26 16:03:11 yamt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_meter.c,v 1.56.4.7 2012/01/11 00:08:41 yamt Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -322,6 +322,12 @@
                       SYSCTL_DESCR("Whether try to zero pages in idle loop"),
                       NULL, 0, &vm_page_zero_enable, 0,
                       CTL_VM, CTL_CREATE, CTL_EOL);
+       sysctl_createv(clog, 0, NULL, NULL,
+                      CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
+                      CTLTYPE_BOOL, "loanread",
+                      SYSCTL_DESCR("Use page loaning for read"),
+                      NULL, 0, &vm_loan_read, 0,
+                      CTL_VM, CTL_CREATE, CTL_EOL);
 
        uvmpdpol_sysctlsetup();
 }