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Tag: KDE

Using setitimer of your favorite posix kernel

Using setitimer of your favorite posix kernel

As this was requested in a comment of a previous post and knowing your kernel helps to write better performing systems here is a small information of how to use the interval timers provided by your posix kernel. What is the interval itime?r The interval timer is managed and provided by your kernel. Everytime the interval of the timer expires the kernel wil send a signal to your application. The kernel is providing three different interval timers for every application….

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Dealing with Performance Improvements

Dealing with Performance Improvements

I hope this post is educational and help the ones among us doing performance optimisations without any kind of measurement. If you do these things without a benchmark you are either a genuis or very likely your application is going to run slower. I’m not going to talk about performance analysis right now but tools like OProfile, callgrind, sysprof and speedprof are very handy utilities. The reason I’m writing this up is that I saw a performance regression in one…

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Conclusions of my QtWebKit performance work

Conclusions of my QtWebKit performance work

My work on QtWebKit performance came to a surprising end late last month. It might be interesting for others how QtWebKit compares to the various other WebKit ports, where we have some strong points and where we have some homework left todo and where to pickup from where I had to leave it. Memory consumption Before I started our ImageDecoderQt was decoding every image as soon as the data was complete. The biggest problem with that is that the ImageSource…

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Reverse engineering with okteta

Reverse engineering with okteta

In the last week I was hacking on OpenBSC to make GSM 12.21 Software Load usable for the ip.access nanoBTS. The difficulta was not within GSM 12.21 as Harald had it implemented for the Siemens BS11 BTS. The difficulty was that some messages need to contain paramaters and these come directly from the firmware file which ultimately means that one needs to understand the firmware file format to extract these. okteta came to rescue me and it was extremely good…

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Looking back to 2009

Looking back to 2009

The second year as part time freelancer has passed. Looking back the most significant things are: Signing the contribution agreement for gdb and glibc with the Free Software Foundation and trying to contribute to both projects. So picking future work will always have to be compatible with this. Hacked on OpenBSC. At first just simple stuff like a telnet interface, paging and later doing paid work for On Waves to add SCCP over IP, GSM 08.08 and other things for…

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(Qt)WebKit Sprint in Wiesbaden

(Qt)WebKit Sprint in Wiesbaden

The sprint is over for some time. You can see summaries of the different sessions and some slides in the wiki. Besides talking about QtWebKit and how to improve it (API, features, speed, make people aware that they can contribute, influence the release schedule, policies.. *hint*) the thing that has impressed me the most is unrelated to coding. We all hear when someone from our Community is leaving the Qt department, and we always wonder how life will continue, who…

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Talking about performance measurements at foss.in

Talking about performance measurements at foss.in

It is the second time I’m at foss.in and this time I was talking about the current work I’m doing on QtWebKit. Nokia is kind enough to give me enough time to explore the performance of QtWebKit (mostly on Qt Embedded Linux and ARM) and do fixes across the stack in WebKit, Qt or whereever we think it will be necessary. Performance for me comes in memory footprint and runtime speed (how long does it take?) and for this I…

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Attending foss.in

Attending foss.in

Thanks to generous sponsoring I managed to make it to Bangalore for FOSS.IN and Girish kindly agreed to provide accomodation. It is really great to be in India again, to see the streets, the local market, catch up with friends from India and Europe. Girish is currently struggling with plugin code in QtWebKit for Mac, Win and X11 in both window and windowless mode, in the good ole wold and in QGraphicsView… I’m analyzing the loading behavior of a particular…

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Collecting hints to increase performance in Qt (and apps)

Collecting hints to increase performance in Qt (and apps)

I’m working part time on improving the performance of QtWebKit (memory usage and raw speed) and I have created some tools to create an offline copy of a number of webpages (gmail, yaho mail, google, news sites…). Using these sites I have created special purpose benchmark reductions. E.g. only do the image operations we do while loading, while loading an painting, load all network resources. One thing I have noticed is that with a couple of small things one can…

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Painting on ARM

Painting on ARM

I’m currently work on making QtWebKit faster on ARM (hopefully later MIPS hardware) and in my current sprint I’m focused on the painting speed. Thanks to Samuel Rødal my work is more easy than before. He added a new paintengine and graphicssystem that allows to trace the painting done with QPainter and then later replay that. Some of you might feel reminded of Carl Worth’s post that mostly did the same for cairo. How to make painting faster? The Setup…

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