Subject: accounting daemon bug fixed + sysctl accounting threshold (#415)
Index:	 sys/subr_log.c,kern_sysctl.c,kern_acct.c 2.11BSD

Description:
	1. A bug in the circular buffer logic would cause the accounting daemon
	to repeatedly read the same data creating very large accounting files.

	2. The threshold of accouting events after which a wakeup() would be
	done on the accounting daemon was hard coded at 10.

Repeat-By:
	1. After applying updates 412 and 413 run the system for a little while
	and notice that /usr/adm/acct was many megabytes in size.

	2. Observation.

Fix:
	1.  Two lines of code which had been deleted the last time this bug
	    was fixed somehow reappeared.  They have been deleted again. This
	    time forever ;)

	2. A sysctl(8) interface to examine and change the number of accounting
	   events that must occur before a wakeup() of acctd(8) was added.  The
	   default is 10 (10 records are buffered by the kernel before waking
	   up the daemon).  To change this to a value between 0 and 128 
	   (inclusive) use:

		sysctl -w kern.acctthresh=6

	    If a value of 0 or 1 is specified then acctd(8) is notified after
	    each accounting record is placed in the buffer.  This is a fair
	    amount of extra overhead and is probably only desireable when
	    testing.

	    To simply examine the current setting:

		sysctl kern.acctthresh

	To install this patch cut where indicated and save to a file (/tmp/415).

	Then:

		patch -p0 < /tmp/415
		cd /sys/YOURKERNEL
		make
		mv /unix /ounix
		mv /netnix /onetnix
		mv unix netnix /
		chmod 744 /unix /netnix

		cd /usr/src/bin/sysctl
		make
		make install

		reboot

	As always this and previous updates to 2.11BSD are available via
	anonymous FTP to either FTP.IIPO.GTEGSC.COM or MOE.2BSD.COM in the
	directory /pub/2.11BSD.

-------------------------cut here----------------------
*** /usr/src/sys/sys/subr_log.c.old	Tue Mar  9 19:44:56 1999
--- /usr/src/sys/sys/subr_log.c	Thu Apr 29 19:46:29 1999
***************
*** 3,9 ****
   * All rights reserved.  The Berkeley software License Agreement
   * specifies the terms and conditions for redistribution.
   *
!  *	@(#)subr_log.c	2.0 (2.11BSD) 1998/12/5
   */
  
  /*
--- 3,9 ----
   * All rights reserved.  The Berkeley software License Agreement
   * specifies the terms and conditions for redistribution.
   *
!  *	@(#)subr_log.c	2.1 (2.11BSD) 1999/4/29
   */
  
  /*
***************
*** 170,177 ****
  		if	(error)
  			break;
  		mp->msg_bufr += l;
- 		if	(mp->msg_bufr < 0 || mp->msg_bufr >= MSG_BSIZE)
- 			mp->msg_bufr = 0;
  		}
  	splx(s);
  	return(error);
--- 170,175 ----
*** /usr/src/sys/sys/kern_acct.c.old	Sat Mar 20 20:43:51 1999
--- /usr/src/sys/sys/kern_acct.c	Thu Apr 29 19:59:36 1999
***************
*** 3,9 ****
   * All rights reserved.  The Berkeley software License Agreement
   * specifies the terms and conditions for redistribution.
   *
!  *	@(#)kern_acct.c	3.0 (2.11BSD) 1999/2/19
   *
   * This module is a shadow of its former self.  This comment:
   *
--- 3,9 ----
   * All rights reserved.  The Berkeley software License Agreement
   * specifies the terms and conditions for redistribution.
   *
!  *	@(#)kern_acct.c	3.1 (2.11BSD) 1999/4/29
   *
   * This module is a shadow of its former self.  This comment:
   *
***************
*** 20,25 ****
--- 20,26 ----
  #include "acct.h"
  
  	comp_t	compress();
+ 	int	Acctthresh = 10;
  
  /*
   * On exit, write a record on the accounting file.
***************
*** 54,65 ****
  	ap->ac_flag = u.u_acflag;
  /*
   * Not a lot that can be done if logwrt fails so ignore any errors.  Every
!  * 10 commands call the wakeup routine.  This isn't perfect but does cut 
!  * down the overhead of issuing a wakeup to the accounting daemon every 
!  * single accounting record.
  */
  	logwrt(ap, sizeof (*ap), logACCT);
! 	if	(acctcnt++ > 10)
  		{
  		logwakeup(logACCT);
  		acctcnt = 0;
--- 55,66 ----
  	ap->ac_flag = u.u_acflag;
  /*
   * Not a lot that can be done if logwrt fails so ignore any errors.  Every
!  * few (10 by default) commands call the wakeup routine.  This isn't perfect 
!  * but does cut down the overhead of issuing a wakeup to the accounting daemon 
!  * every single accounting record.  The threshold is settable via sysctl(8)
  */
  	logwrt(ap, sizeof (*ap), logACCT);
! 	if	(++acctcnt >= Acctthresh)
  		{
  		logwakeup(logACCT);
  		acctcnt = 0;
*** /usr/src/sys/sys/kern_sysctl.c.old	Tue Sep 15 19:57:05 1998
--- /usr/src/sys/sys/kern_sysctl.c	Thu Apr 29 20:18:27 1999
***************
*** 33,39 ****
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
!  *	@(#)kern_sysctl.c	8.4.9 (2.11BSD GTE) 1998/9/15
   */
  
  /*
--- 33,39 ----
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
!  *	@(#)kern_sysctl.c	8.4.10 (2.11BSD) 1999/4/29
   */
  
  /*
***************
*** 186,191 ****
--- 186,192 ----
  	int error, level;
  	u_long longhostid;
  	char bsd[10];
+ 	extern int Acctthresh;		/* kern_acct.c */
  	extern char version[];
  
  	/* all sysctl names at this level are terminal */
***************
*** 199,204 ****
--- 200,216 ----
  		bsd[0]='2';bsd[1]='.';bsd[2]='1';bsd[3]='1';bsd[4]='B';
  		bsd[5]='S';bsd[6]='D';bsd[7]='\0';
  		return (sysctl_rdstring(oldp, oldlenp, newp, bsd));
+ 	case KERN_ACCTTHRESH:
+ 		level = Acctthresh;
+ 		error = sysctl_int(oldp, oldlenp, newp, newlen, &level);
+ 		if	(newp && !error)
+ 			{
+  			if	(level < 0 || level > 128)
+ 				error = EINVAL;
+ 			else
+ 				Acctthresh = level;
+ 			}
+ 		return(error);
  	case KERN_OSREV:
  		return (sysctl_rdlong(oldp, oldlenp, newp, (long)BSD));
  	case KERN_VERSION:
*** /usr/src/sys/h/sysctl.h.old	Thu Jan 19 21:20:50 1995
--- /usr/src/sys/h/sysctl.h	Thu Apr 29 20:02:11 1999
***************
*** 33,39 ****
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
!  *	@(#)sysctl.h	8.1.2 (2.11BSD GTE) 1/19/95
   */
  
  #ifndef _SYS_SYSCTL_H_
--- 33,39 ----
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
!  *	@(#)sysctl.h	8.1.3 (2.11BSD) 1999/4/29
   */
  
  #ifndef _SYS_SYSCTL_H_
***************
*** 135,141 ****
  #define	KERN_BOOTTIME		21	/* struct: time kernel was booted */
  #define	KERN_MAXTEXTS		22	/* int: # of text entries */
  #define	KERN_TEXT		23	/* struct: text entries */
! #define	KERN_MAXID		24	/* number of valid kern ids */
  
  #ifndef	KERNEL
  #define CTL_KERN_NAMES { \
--- 135,142 ----
  #define	KERN_BOOTTIME		21	/* struct: time kernel was booted */
  #define	KERN_MAXTEXTS		22	/* int: # of text entries */
  #define	KERN_TEXT		23	/* struct: text entries */
! #define	KERN_ACCTTHRESH		24	/* int: accounting daemon threshold */
! #define	KERN_MAXID		25	/* number of valid kern ids */
  
  #ifndef	KERNEL
  #define CTL_KERN_NAMES { \
***************
*** 163,168 ****
--- 164,170 ----
  	{ "boottime", CTLTYPE_STRUCT }, \
  	{ "maxtexts", CTLTYPE_INT }, \
  	{ "text", CTLTYPE_STRUCT }, \
+ 	{ "acctthresh", CTLTYPE_INT }, \
  }
  #endif
  
*** /usr/src/bin/sysctl/sysctl.8.old	Fri Apr  3 20:33:02 1998
--- /usr/src/bin/sysctl/sysctl.8	Thu Apr 29 20:41:21 1999
***************
*** 29,37 ****
  .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  .\" SUCH DAMAGE.
  .\"
! .\"	@(#)sysctl.8	8.1.4 (2.11BSD GTE) 1998/4/3
  .\"
! .TH SYSCTL 8 "June 6, 1993"
  .UC 4
  .SH NAME
  sysctl \- get or set kernel state
--- 29,37 ----
  .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  .\" SUCH DAMAGE.
  .\"
! .\"	@(#)sysctl.8	8.1.5 (2.11BSD) 1999/4/29
  .\"
! .TH SYSCTL 8 "April 24, 1999"
  .UC 4
  .SH NAME
  sysctl \- get or set kernel state
***************
*** 109,114 ****
--- 109,115 ----
  .ta 0.5i 3.0i 4.0i
  .nf
  	Name	Type	Changeable
+ 	kern.acctthresh	int	yes
  	kern.ostype	string	no
  	kern.osrelease	string	no
  	kern.osrevision	long	no
*** /VERSION.old	Wed Apr 28 21:51:19 1999
--- /VERSION	Thu Apr 29 19:45:43 1999
***************
*** 1,5 ****
! Current Patch Level: 414
! Date: April 28, 1999
  
  2.11 BSD
  ============
--- 1,5 ----
! Current Patch Level: 415
! Date: April 29, 1999
  
  2.11 BSD
  ============