Subject: Re: bin/20316: systat interrupt counters
To: David Laight <david@l8s.co.uk>
From: Johnny Billquist <bqt@update.uu.se>
List: netbsd-bugs
Date: 02/12/2003 23:51:30
On Wed, 12 Feb 2003, David Laight wrote:

> > systat have recently had the "new" interrupt counters added.
> > However, when displaying the names of these counters, systat prefers
> > displaying the counter name to the counter group name.
> > This is wrong, I believe.
> 
> I do not believe so.  On i386 the full names are:
> 	group	counter
> 	cpu0	softclock
> 	cpu0	softnet
> 	cpu0	softserial
> 	pic0	pin 14
> 	pic0	pin 10
> 	pic0	pin 9
> 	pic0	pin 4
> 	pic0	pin 3
> 	pic0	pin 1
> 	pic0	pin 12
> 	pic0	pin 0
> 
> So just showing the group names would be rather pointless.

Sigh. The same problem but the other way...

> > The counter name is group specific, and is not guaranteed to be unique.
> True, but there are very likely to be many counters in a single grpoup.

To quote the man-page (9 evcnt):
     Each event counter also has a group name (ev_group) and an event name
     (ev_name) which are used to identify the counter.  The group name may be
     shared by a set of counters.  For example, device interrupt counters
     would use the name of the device whose interrupts are being counted as
     the group name.  The counter name is meant to distinguish the counter
     from others in its group (and need not be unique across groups).

Given this, the group name ought to be the most "interesting" name to
display. Take as much of the rest as possible, truncating at the right
end.

> > By prefering to show this string if both strings don't fit, you get a list
> > that is difficult to decipher.
> 
> > In addition systat also truncates group and name if they don't fit, which
> > removed important information.
> 
> Run systat in a wider window.  Both are actually allowed to be quite long.

I'm running on a VAX. What do you mean "wider window"? My VT320 is as wide
as it is.

> > The name of the event counter is often just "intr"
> > (atleast on VAXen), which means you just get a lists with "intr".
> 
> The display looks a lot better on i386, I put it to you that there are
> more i386 systems running netbsd than vax.

I can't argue with that one.

> Perhaps the actual problem is the unhelpful naming of the counters.

I really cannot do, or say much more on the subject. Could someone who
designed the evcnt stuff perhaps clarify what is to be expected in the two
strings.

On my VAX, it currently looks like this, anyway:
interrupt                                        total     rate
                                                     0        0
crl	intr                                         0        0
uba	stray intr                                   0        0
uba0	intr                                       164        0
mtc0	intr                                         6        0
uda0	intr                                    315053        3
de0	intr                                    513282        5
dmf0	srintr                                       0        0
dmf0	stintr                                       0        0
dmf0	piva                                         0        0
dmf0	pivb                                         0        0
dmf0	arintr                                   15723        0
dmf0	axintr                                   19283        0
dmf0	lpintr                                       0        0
uba1	intr                                         0        0
mtc1	intr                                         6        0
uda1	intr                                    536097        5
soft	serial                                       0        0
soft	net                                     178646        1
soft	clock                                   161566        1
clock	intr                                  10252164      100

	Johnny

Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email: bqt@update.uu.se           ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol