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.;KLBPA %1(1) users manual				RDH  --  12-SEP-79
.;
.;This file produces KLBPA.MAN,  a general manual for the use
.;of the KLBPA program.
.;
.;This document reflects KLBPA %1(1) as of 12-Sep-79
.;
.;
.;
.PS 59,80
.LM 0
.RM 80
.PAGING
.NUMBER PAGE 0
.TITLE KLBPA %1(1) Users Reference Manual
.SUBTTL
.;Copyright
.BLANK 10
.CENTER
KLBPA %1(1) users reference manual
.SKIP 20
Copyright (C) 1979
.BREAK
Digital Equipment Corporation, Maynard, Massachusetts, U.S.A.
.SKIP
This software is furnished under a license and may be used and copyed only
in accordance with the terms of such license and with the inclusion of the
above copyright notice.  This software or any other copies thereof may not
be provided or otherwise made available to any other person.   No title to
and ownership of the software is hereby transferred.
.SKIP
The information in this software is subject to change  without  notice and
should not be construed as a commitment by Digital Equipment Corporation.
.SKIP
Digital  assumes  no  responsibility  for  the  use  or reliability of its
software on equipment which is not supplied by Digital.
.SUBTTL Introduction
.PAGE
.AUTOP

KLBPA (KL-10 Background Performance Analysis) is a program to
control the gathering of general "background" system performance statistics
of a 7-series TOPS-10 monitor via the performance meter available
on all KL-10 cpus. As such, KLBPA is meaningful only for KL-10
based TOPS-10 systems.

In order to use KLBPA you must be running under the OPR account.

.SUBTTL Background Performance Analysis Overview.
.PAGE

KL-10 processors come equipped with a very powerful and very
flexible analytical tool called the "Performance Meter" or
"Performance Meter Board", hereinafter referred to as
simply the "meter". The meter allows measurement of a wide
variety of operating conditions or events which take place
under the control of the KL-10 cpu.

The meter operates in one of two modes - duration mode
or event mode. In duration mode the meter measures the amount of
time (the duration of) a condition occurs. In event mode
the meter counts how many times (events) a condition
occurs.

The meter can measure user mode versus executive mode, interrupt
level processing, RH20 channel to memory usage, memory usage
(from which the cache hit ratio can be calculated), and a number of
other conditions. The meter can even measure a microcode-controlled
condition, enabling the KL-10 to, for example, count the number of
times an ILDB instruction is executed (or the amount of
time spent executing ILDB instructions). To use the microcode in
conjunction with the meter requires modifying the microcode.

For details on exact meter operation read the DECsystem-10 Hardware
Reference Manual.

The meter is available to user programs via the PERF. monitor
call. For details on how to use the PERF. monitor call read the
TOPS-10 7.00 Monitor Calls Manual.

Starting with the 7.00 release of the TOPS-10 monitor the monitor
itself can use the meter to gather system-wide operating statistics
independent of user programs. If a specific user program has a cpu's
meter in use then the monitor can not use that cpu's meter (when
the job releases the meter the monitor will automatically resume
its background usage, if enabled).

If the meter is available to the monitor then the monitor will (on
orders from, for example, KLBPA) enable the meter and leave it
running "in the background" gathering statistics.

The monitor has a command table (in the COMMON module) which contain
meter commands. The monitor will round-robin through the command
table passing successive conditions to the meter. A user-settable
sampling interval controls how often the meter command is changed.

At the end of a sample interval the monitor reads the meter value
and the elapsed time and adds them into a CDB variables subtable
(GETTAB item %CCBPA), then steps to the next command, reenables
the meter, and continues. The monitor sampling is driven by the
monitor clock interrupt service, which, running at the APR PI level
(the highest ever used by the monitor), gives a very accurate sampling
interval.

It is important to note that the monitor has no idea what the
meter is doing, the monitor merely picks up the 36-bit meter
command from the meter command table, passes the command to the
meter, then later reads what the meter has "counted", as well as
the interval for which the meter was enabled. Any interpretation
of the statistics so gathered is left to user programs.

With the 7.00 release of the monitor the meter commands table has
16 (decimal) entries, the first eight of which watch the RH20 to
MBOX interactions, and the second eight of which watch the amount
of time spent at various interrupt levels. All sixteen entries are
duration mode. 

KLBPA itself does not do anything with the background performance
statistics, the ONLY function of KLBPA is to control whether or not
said statistics are gathered.
SYSDPY %434(562) will display these statistics as part of the
"system" display for any cpu which is enabled to maintain them.
See the SYSDPY manual for details.
.SUBTTL Commands
.PAGE

KLBPA will prompt the user with a "/" character. At this
point the user may type in a single command to KLBPA. Commands to
KLBPA are of the form of action keywords, optionally followed by any
arguments (similar to BACKUP).

The commands to KLBPA are:
.B1
.LM 16
.TS 16
.I -16
[NO]ALL	Enable [Disable] all cpus. The "ALL" command instructs KLBPA
to turn on the performance meter for all cpus in the system. The NOALL
command instructs KLBPA to turn off the performance meter for all cpus
in the system.
.b1;.i -16
[NO]CLEAR	Do [not] zero the statistics tables when enabling a cpu.
The CLEAR command instructs KLBPA to have the monitor zero the per-cpu
statistics table when the cpu is enabled for performance measurements.
The NOCLEAR command instructs KLBPA to not cause the per-cpu statistics
table to be cleared when a cpu is enabled. The [NO]CLEAR command is a
status switch which will affect all subsequent enable/disable commands.
.B1;.I -16
[NO]CPU0	Enable [Disable] only CPU0. The CPU0 command enables
background performance statistics gathering only for CPU0. The NOCPU0
command disables background performance statistics gathering only
for CPU0.
.B1;.I -16
[NO]CPU1	Enable [Disable] only CPU1. The CPU1 command enables
background performance statistics gathering only for CPU1. The NOCPU1
command disables background performance statistics gathering only
for CPU1.
.B1;.I -16
[NO]CPU2	Enable [Disable] only CPU2. The CPU2 command enables
background performance statistics gathering only for CPU2. The NOCPU2
command disables background performance statistics gathering only
for CPU2.
.B1;.I -16
[NO]CPU3	Enable [Disable] only CPU3. The CPU3 command enables
background performance statistics gathering only for CPU3. The NOCPU3
command disables background performance statistics gathering only
for CPU3.
.B1;.I -16
[NO]CPU4	Enable [Disable] only CPU4. The CPU4 command enables
background performance statistics gathering only for CPU4. The NOCPU4
command disables background performance statistics gathering only
for CPU4.
.B1;.I -16
[NO]CPU5	Enable [Disable] only CPU5. The CPU5 command enables
background performance statistics gathering only for CPU5. The NOCPU5
command disables background performance statistics gathering only
for CPU5.
.B1;.I -16
TICKS:nnn	Set measurement cycling interval to nnn clock ticks.
The TICKS command sets the interval between successive samples read from
the performance meter. The TICKS command is a status-setting command
which affects all subsequent enabling commands. The default value for
the sampling interval is one clock tick.