[Xastir-Dev] Re: Re: CPU still too busy for the wrong reasons

[Tom Russo]

On Fri, Nov 28, 2003 at 05:59:28PM -0800, a Mr. Richard Feyler of Fort Lee, New Jersey <archer at eskimo.com> writes 'Dear Rosanne Rosannadanna':
> On Fri, 28 Nov 2003, Jerry Chamberlin wrote:
> 
> > Mine is RH 6.2 and RG 7.2 both do it.
> 
> Is there a case where it doesn't do it?  For instance try shutting
> off all interfaces, then try turning off dead-reckoning, then try
> turning off weather alerts, etc.  All the things I mentioned in my
> other e-mail (plus weather alerts).

In my case, none of these suggestions has any effect.  If I am running
xastir, it is taking all available CPU.  Right now, with all interfaces
turned off, dead reckoning off, weather alerts off, all networked maps 
disabled, basically just sitting there displaying static maps and no
stations, it's taking 97% of the laptop's CPU.


I did build xastir with profiling turned on and checked what's taking the
time.  In a 3 minute run, UpdateTime was called once.  During that
call, there were some amazingly huge numbers:  sec_now was called 2.3million
times.  check_statusline_timout, popup_timeout_check, 
check_and_transmit_objects_items, and several other routines had 236,626 calls 
each. 

There were also a very huge number of calls to various pthread-related
calls:  I'm out of practice reading gprof output, but it looks like
over 70 million calls to pthread_mutex_lock.  Remember, this is in a 3 minute
run of xastir, with one internet server interface turned on.

> If Xastir does it in all conditions, it's most likely that the
> UpdateTime() routine is running too often.  

In my case it's doing this under all conditions.  Gprof shows only a single
UpdateTime call in the whole 3 minutes, but it and its children took up 
63.15 seconds and 76.2% of the run time.  (not sure how gprof gets that number 
--- it says main and *its* decendents took only 67.44 seconds and accounted 
for 81% of the time)

-- 
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/
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