[comp.sys.hp] what is msmod?

njw@doc.ic.ac.uk (Nick Williams) (03/09/91)

Browsing through manual pages, binaries and other assorted locations
the other day, I found we have a program installed in /etc called
msmod.

There is no manual page but on startup it says:
	$Header: msmod.c,v 64.1 89/04/28 17:00:02 marcs Exp $

	User interface is likely to change.
	This version is preliminary.
	Comments and suggestions are encouraged.

It allows the superuser to activate or deactivate measurements of all
sorts of cute things, it seems, by using a device /dev/meas_drivr...

Anybody know anything about this program? What it really does? How it
displays its results? Or, is it even safe/useful to use?  (hpux7.0,
hp9000s300)

This is what happens if you spend boring afternoons poring over hpux,
instead of working...

Nick.
--
njw@doc.ic.ac.uk    Dept of Computing, Imperial College, London SW7 2B7.  UK
njw@athena.mit.edu  Project Athena, M.I.T., Cambridge, MA 02139. USA
(Andrew multi-media mail received and understood)

The ISO Standard Disclaimer should go here,
	unfortunately I didn't have enough disk space...

dah@hpcupt1.cup.hp.com (Dave Holt) (03/16/91)

The official story is that, like several other undocumented programs
in /etc, it's supported for HP field use only (and customers by 
special arrangement).

Now that the appropriate disclaimers are out of the way, msmod is the 
control program for the kernel measurement system, which has been part 
of HP-UX since 1.0 on the s800 and ~6.2 on the s300.

Msmod manages the trace points in the kernel, while iscan (also in /etc)
snarfs trace data from the kernel.  Iscan outputs binary data (for speed)
which can be parsed into ascii by /etc/translate.  At this point you
have a file full of numbers suitable for analysis by awk scripts, etc.

Unfortunately the set of instrumentation points in the s300 kernel
is not as rich as that of the s800 kernel, but you might have some fun
anyway.

Poke me if you'd like to try doing more with it (I wrote it about 5 years 
ago, and have been maintaining it in my spare time).

				Dave Holt
				HP-UX Kernel Performance (until the reorg)
				dah@hpda.cup.hp.com

mjf@mjm.mjm.com (Mark Fresolone) (03/20/91)

>/ mjm:comp.sys.hp / njw@doc.ic.ac.uk (Nick Williams) / 2:33 pm  Mar  8, 1991 /

>It allows the superuser to activate or deactivate measurements of all
>sorts of cute things, it seems, by using a device /dev/meas_drivr...
True.

>Anybody know anything about this program?	// Yes, though read on.

>What it really does?		//Your above description is pretty accurate.

>How it >displays its results?
Msmod(1) requests buffer allocation and measurement invocation in the
kernel.  The kernel measurement routines simply make binary measurements
available in kernel buffers (contrary to the apparent intent of
/dev/meas_drivr).  Other software opens /dev/kmem, and empties the circular
buffer.  Yet-other applications can be used to generate reports on the
data once brought out into user-land.

>Or, is it even safe/useful to use?  (hpux7.0, >hp9000s300)
The kernel and user software that msmod(1) is a part of is not documented
or intended for use outside of HP.  You seem aquainted with the disclaimers
that normally follow  ("ISO disclaimer..." et.al.).

HP uses this Measurement System and other HP-developed kernel statistics
software to provide performance analysis tools such as those found in the
HP "XEnvironment" product.  In vue of HP-VUE and other recent HP-UX
productizations, I couldn't tell you where this stuff shows up in HP's
price list nowadays.

>This is what happens if you spend boring afternoons poring over hpux,
>instead of working...
Tell me...........

>Nick.

Mark Fresolone					mjf@mjm.com, rutgers!mjm!mjf
Melillo Consulting/MJM Software			908-873-0075/Fax 908-873-2250