Dear Norman,

  Thank you for spending much time on answering my problems.

  Maybe I should consider the time cost of using DoPE on Genode, because my work should be finished before February, 2015.

 Then my answers are given below:

* Which version of Genode are you using?

We're using version 13.02.


* Are you using Qt4 or Qt5? (If you are still using Qt4, I would
recommend you to switch to Qt5)

Qt 4.7.4 was using. I tried to replace Qt4 with Qt5, but failed. The reason maybe the ways I used are wrong because of my lack of knowledge about that. So, could you give me some tips or tutorial about Qt4's updating to Qt5? Sorry to bother you, Norman. 


* Which Genode base platform are you using?

Fiasco.OC, because our prototype and research are all based on microkernel architecture till now.


* Have you tried to run your GUI application on base-linux? If yes,
  have you compared its performance to the same application compiled for native Linux w/o Genode?

I would like to carry some experiments before giving an answer to you.


* On base-linux, you could use normal Linux profiling tools such as
oprofile to find out where the CPU time goes.

It's good way, but I should consider how to make sure that Fiasco.OC-based Genode's performance is improved.


* Can you make a Git branch with your application publicly available
(e.g., on Github) so that I could give it a try? By being able
to reproduce the problem, I could help you much better with
investigating the issue.

I'm so sorry for being not able to do this, because parts of source code of our prototype could not be public. I really appreciate you help, and if some day our team leader agree to open source code to the public, I would like to invite you to our team.


Thank you for all your assistance.  


Yours Sincerely,

Shuo Wang
University of Chinese Academy of Sciences.


------------------ Original ------------------
From:  "norman.feske";<norman.feske@...1...>;
Date:  Thu, Mar 27, 2014 09:45 PM
To:  "genode-main"<genode-main@lists.sourceforge.net>;
Subject:  Re: Some questions about performance optimization related to GUIframework on Genode

Hello Shuo Wang,

thank you for your interest in Genode! Please excuse the delayed
response. I was offline for a few days.

>    The most serious problem I meet now is that system is very slow when
> running applications we made before, so I doubt whether this is related
> to GUI framework. I plan to transplant DoPE to Genode, in order to make
> a comparation between DoPE and Qt. But I am worried about reasonability
> about my design of experiments, so I need help from the developers.

DOpE is definitely faster than Qt as it is even usable on
low-performance devices such as FPGA softcores, e.g., the Milkymist SoC
[1]. So for those kind of special-purpose appliances, DOpE still seems
to be attractive. However, in the context of the Genode OS framework, I
would advise against using DOpE. I would rather spend the energy on
investigating the performance problems you observe with Qt.

[1] http://m-labs.hk/m1.html

The reason for my stance is that DOpE lacks a lot of features that are
universally expected from modern GUI toolkits (e.g., support for
theming, international characters, common widget types like menus).
Furthermore, it has been practically unmaintained for several years now.
If you still like to go forward with experimenting with DOpE on Genode,
I can possibly assist you. I already ported DOpE to an early version of
Genode in 2008 and could possibly revive the port. However, I am not
committed to actively maintain or even improve it.

As I said above, I would rather try to find out why Qt performs so badly
for you. This raises the following questions:

* Which version of Genode are you using?

* Are you using Qt4 or Qt5? (If you are still using Qt4, I would
  recommend you to switch to Qt5)

* Which Genode base platform are you using?

* Have you tried to run your GUI application on base-linux? If yes,
  have you compared its performance to the same application compiled for
  native Linux w/o Genode?

* On base-linux, you could use normal Linux profiling tools such as
  oprofile to find out where the CPU time goes.

* Can you make a Git branch with your application publicly available
  (e.g., on Github) so that I could give it a try? By being able
  to reproduce the problem, I could help you much better with
  investigating the issue.

Best regards
Norman

--
Dr.-Ing. Norman Feske
Genode Labs

http://www.genode-labs.com · http://genode.org

Genode Labs GmbH · Amtsgericht Dresden · HRB 28424 · Sitz Dresden
Geschäftsführer: Dr.-Ing. Norman Feske, Christian Helmuth

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