Performance problem

Performance problem

[Gregor Pavlin]

Hi,


I'm trying to configure a small, embedded Linux system (Pentium III
1000MHz), that supports Java+X-Windows. In any case, the Java application
runs very slowly. Even worse, the same application runs on a Linux-system
with a (Pentium III 450MHz)twice as fast.

Initially I thought that it was the X-server configuration problem but now I
guess that it has to do with scheduling. Namely, when I checked the
processes with "top" on both systems and got interesting results:


System with (Pentium III 1000MHz):

Java stuff was assigned less than 30% of the CPU
X windows used more than 60% of the CPU resources.


System with (Pentium III 450MHz):

Java more than 80% of the CPU
X windows few % of the CPU resources.



In order to influence the CPU sharing on the slow computer (Pentium III
1000MHz) I tryed "nice --20 /$PATH/java-application". However, this doesn't
result in a significant improvement in performance.



Therefore I have the following questions:


1.) Can this be a scheduler's problem?

2.) If so, are there any other ways I can influence the scheduler, e.g. the
policy without recompiling the Kernel?

3.) I'm using a read-only mounted file systems with about 10 MB RAM-disk and
no Swapping. Could these features be a problem in the context of threads and
X-Windows?




Thank you in advance.

Regards,
Gregor



----------------------------

Gregor Pavlin

email: g.pavlin@gmx.at
Tel.:++43 316 244233
     ++43 316 289402
Fax.:++43 316 244243

Kalsdorferstr. 41,
A-8073, Feldkirchen bei Graz
Austria

Re: Performance problem

[Joseph Bueno]

Gregor Pavlin a écrit :
> 
> Hi,
> 
> I'm trying to configure a small, embedded Linux system (Pentium III
> 1000MHz), that supports Java+X-Windows. In any case, the Java application
> runs very slowly. Even worse, the same application runs on a Linux-system
> with a (Pentium III 450MHz)twice as fast.
> 
> Initially I thought that it was the X-server configuration problem but now I
> guess that it has to do with scheduling. Namely, when I checked the
> processes with "top" on both systems and got interesting results:
> 
> System with (Pentium III 1000MHz):
> 
> Java stuff was assigned less than 30% of the CPU
> X windows used more than 60% of the CPU resources.
> 
> System with (Pentium III 450MHz):
> 
> Java more than 80% of the CPU
> X windows few % of the CPU resources.
> 
> In order to influence the CPU sharing on the slow computer (Pentium III
> 1000MHz) I tryed "nice --20 /$PATH/java-application". However, this doesn't
> result in a significant improvement in performance.
> 
> Therefore I have the following questions:
> 
> 1.) Can this be a scheduler's problem?
> 
> 2.) If so, are there any other ways I can influence the scheduler, e.g. the
> policy without recompiling the Kernel?
> 
> 3.) I'm using a read-only mounted file systems with about 10 MB RAM-disk and
> no Swapping. Could these features be a problem in the context of threads and
> X-Windows?
> 
> Thank you in advance.
> 
> Regards,
> Gregor
> 
> ----------------------------
> 
> Gregor Pavlin
> 
> email: g.pavlin@gmx.at
> Tel.:++43 316 244233
>      ++43 316 289402
> Fax.:++43 316 244243
> 
> Kalsdorferstr. 41,
> A-8073, Feldkirchen bei Graz
> Austria
> 
Hi,

What makes you think that this is NOT an Xserver problem ?
What you describe would be normal if your P450 has an accelerated
video board with an optimised Xserver and your P1000 an unaccelerated
VGA Xserver.

Have you tried to compare Xwindow graphics performance on your
machines ?
Some X benchmark program (xbench) could be useful.

Hope this helps
--
Joseph Bueno
NetClub/Trader.com
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