[Xastir] Xastir -CPU

[Tom Russo]

On Thu, Sep 16, 2004 at 07:17:53PM -0700, a Mr. Richard Feyler of Fort Lee, New Jersey <archer at eskimo.com> writes 'Dear Rosanne Rosannadanna':
> On Thu, 16 Sep 2004, Tom Russo wrote:
> 
> > On Windows 2000, on another 2GHz machine with 640MB ram, we're looking at
> > 80%-90% CPU usage with the only feed being the server port on the above home
> > machine.  Spikes up to 90+% every time there's a packet received or an expose
> > event, drops to around 82% and stays there when everything's quiet.  X doesn't
> > eat that CPU when xastir is not running, but it's clearly related to xastir's
> > use of X.
> 
> Henk de Groot has been keeping me informed of such things.  I think
> he may do a bit more work on getting that CPU usage down on Cygwin.
> I have a hard time finding test machines to do it with.

That's why the kid has a computer, so Dad can have an extra test platform 
without actually claiming to own a Losedows box.  

> If you get a chance though, crank up "nexttime" in
> main.c:UpdateTime() to see if it helps on Cygwin.  Henk was doing
> some of that and got it down to 30% or so.  If you can do a bit more
> and track down where the CPU is really getting used, that'd be even
> better.  We can put in Cygwin-specific delays once we find the
> culprit, or code around the problem.

Xastir is, in fact, using very, very little of the CPU on windows.

Looking at Windows Task Manager, xastir rides around 1-5% of the CPU.  Where 
all that time is being eaten is in the "System" process, and it is indeed very
sensitive to nexttime in UpdateTime.

With the Cygwin X server running, total system load sits around 2-40% 
(spiking whenever doing complex tasks like raising the bash window to the
front).

At nexttime=2, upon startup xastir floats at single digit CPU percentage,
while System eats nearer to 70%, and the total system load as shown by the
performance monitor is nearer 90%.

At nexttime=20, System  hovers a bit lower, xastir stays in the single 
digits, but average system load is stil near 65%.

At nexttime=50, System is bouncing around between  50-60%, and average system
load is bouncing between 40 and 50%.  This is with a single internet server,
connected directly to my copy of xastir running on a real OS, which is 
currently getting data from a TNC,  heavily filtered aprs2.net and firenet 
feeds over dialup.  Shutting off the internet server does not, in fact, 
change the total CPU utilization very much at all (a percent point or less).

Last test I did was with nexttime=200, which appears to get the total 
CPU usage down to 15-25%.  The little red arrow in the interface graphic
on the bottom right doesn't flicker at the epilepsy-inducing rate it does when
running with much lower nexttimes, but other than that the thing does
seem to be working Just Fine and not consuming the machine.  "System" 
is still the dominant process, xastir is still in the single digits in CPU %.

Gonna leave it running overnight and see how it looks in the morning.

Oh, and BTW --- with the TNC feed, the filterd aprs2 and firenet feeds, and
the connection to the losedows box, my BSD xastir is hovering at 0.3-0.8% CPU 
utilization, with 15 hour uptime.

-- 
Tom Russo    KM5VY     SAR502  DM64ux         http://www.swcp.com/~russo/
Tijeras, NM  QRPL#1592 K2#398  SOC#236 AHTB#1 http://www.qsl.net/~km5vy/
(1) Ignorance of your profession is best concealed by solemnity and silence,
which pass for profound knowledge upon the generality of mankind.
                -------"Advice to Officers of the British Army", 1783