[src/trunk]: src/sys/dev - Increase the default number of buffers, and scale ...

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

details:   https://anonhg.NetBSD.org/src/rev/cf689b429968
branches:  trunk
changeset: 461336:cf689b429968
user:      ad <ad%NetBSD.org@localhost>
date:      Sat Nov 23 17:32:10 2019 +0000

description:
- Increase the default number of buffers, and scale it by ncpu.
- Stop tracing when the device is closed.

diffstat:

 sys/dev/lockstat.c |  20 +++++++++++++-------
 1 files changed, 13 insertions(+), 7 deletions(-)

diffs (60 lines):

diff -r ab3598cd0c97 -r cf689b429968 sys/dev/lockstat.c
--- a/sys/dev/lockstat.c        Sat Nov 23 17:13:46 2019 +0000
+++ b/sys/dev/lockstat.c        Sat Nov 23 17:32:10 2019 +0000
@@ -1,7 +1,7 @@
-/*     $NetBSD: lockstat.c,v 1.25 2017/06/01 02:45:09 chs Exp $        */
+/*     $NetBSD: lockstat.c,v 1.26 2019/11/23 17:32:10 ad Exp $ */
 
 /*-
- * Copyright (c) 2006, 2007 The NetBSD Foundation, Inc.
+ * Copyright (c) 2006, 2007, 2019 The NetBSD Foundation, Inc.
  * All rights reserved.
  *
  * This code is derived from software contributed to The NetBSD Foundation
@@ -37,10 +37,11 @@
  * Only one thread can hold the device at a time, providing a global lock.
  *
  * XXX Timings for contention on sleep locks are currently incorrect.
+ * XXX Convert this to use timecounters!
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: lockstat.c,v 1.25 2017/06/01 02:45:09 chs Exp $");
+__KERNEL_RCSID(0, "$NetBSD: lockstat.c,v 1.26 2019/11/23 17:32:10 ad Exp $");
 
 #include <sys/types.h>
 #include <sys/param.h>
@@ -71,7 +72,7 @@
 #endif
 
 #define        LOCKSTAT_MINBUFS        1000
-#define        LOCKSTAT_DEFBUFS        10000
+#define        LOCKSTAT_DEFBUFS        20000
 #define        LOCKSTAT_MAXBUFS        1000000
 
 #define        LOCKSTAT_HASH_SIZE      128
@@ -453,6 +454,10 @@
 {
 
        lockstat_lwp = NULL;
+       if (lockstat_dev_enabled) {
+               lockstat_stop(NULL);
+               lockstat_free();
+       }
        __cpu_simple_unlock(&lockstat_lock);
        return 0;
 }
@@ -490,9 +495,10 @@
                /*
                 * Sanitize the arguments passed in and set up filtering.
                 */
-               if (le->le_nbufs == 0)
-                       le->le_nbufs = LOCKSTAT_DEFBUFS;
-               else if (le->le_nbufs > LOCKSTAT_MAXBUFS ||
+               if (le->le_nbufs == 0) {
+                       le->le_nbufs = MIN(LOCKSTAT_DEFBUFS * ncpu,
+                           LOCKSTAT_MAXBUFS);
+               } else if (le->le_nbufs > LOCKSTAT_MAXBUFS ||
                    le->le_nbufs < LOCKSTAT_MINBUFS) {
                        error = EINVAL;
                        break;