kern/167321: Implement sysctl to control kernel accounting log messages (e.g. acct(2))

[Jeremy Chadwick]

...and also the patch for the acct(2) man page, documenting this
variable.

-- 
| Jeremy Chadwick                                   jdc at koitsu.org |
| UNIX Systems Administrator                http://jdc.koitsu.org/ |
| Mountain View, CA, US                                            |
| Making life hard for others since 1977.             PGP 4BD6C0CB |

--- SNIP ---

--- src/lib/libc/sys/acct.2.orig	2009-08-03 01:13:06.000000000 -0700
+++ src/lib/libc/sys/acct.2	2012-04-26 05:11:42.670706272 -0700
@@ -87,6 +87,16 @@
 .It Va kern.acct_suspend
 The percentage of free disk space below which process
 accounting will suspend.
+.It Va kern.acct_logging
+If set to 0, the kernel will inhibit console messages indicating when
+accounting is enabled, disabled, suspended, or resumed.  This can be
+useful when the
+.Xr periodic.conf 5
+variable
+.Va daily_accounting_enable
+is set to
+.Dq YES .
+The default value is 1 (enabled).
 .El
 .Sh RETURN VALUES
 On error -1 is returned.