Answers of some questions about performance optimization relatedto GUIframework on Genode

[Norman Feske]

Hello Shuo,

> Have you compared the performance of an unmodified Genode system (e.g.,
> qt5.run) with VSOS?
> I have compared the performance of an unmodified Genode system (both
> 13.02 and 14.08) and VSOS both on qemu and real machine. The performance
> of them are similar which cannot satisfy our team leader/my advisor. He
> thought that it should be faster for apps on Genode (all operations
> should be finished at once), but both unmodified Genode and VSOS cannot
> satisfy him. He thought the problem may be related to inter-process
> communication between Init and ,or interaction between Qt and other
> parts of Genode, but I don't find out the problem in these aspects. 

your observation surprises me. We have recently compared the performance
of Arora (using Qt5, not Qt4!) running on the Pandaboard by measuring
page-load times of large websites like spiegel.de. We found that Arora
running on the base-hw kernel was actually faster than Arora running on
the current version of Ubuntu Linux.

Have you considered to cross-correlate the performance issues using
different kernels? E.g., running the qt5.run script on NOVA instead of
Fiasco.OC? Some workloads are known to be extremely slow on Fiasco.OC.
See [1] for more details.

[1] https://github.com/genodelabs/genode/issues/712

Also, it might be worth considering to test the scenarios on a different
hardware platform and revisit the BIOS settings for power-management.

Finally, I'd like to reinforce what Vasily just said. Please provide us
with a metric for "good" performance.

Best regards
Norman

-- 
Dr.-Ing. Norman Feske
Genode Labs

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