At home

I’m back home, but more importantly, after the trip to Brno, I feel really at home at Red Hat.

Starting a new, hopefully more interesting blog

The present blog is really about recording my day-to-day work. So there is no structure, no storytelling, nothing. And it’s not going to change, because that’s exactly the way I need it to be. It’s really more of a diary than a blog.

That being said, I may occasionally have more interesting things to share. That’s why I just created another blog called A Spice Odyssey, which I consider much more “public”. I will post there less frequently, but the content should be of higher interest to the target audience.

The first post there explains why I feel at home at Red Hat. I also added an entry about a tool that Jean-Yves Avenard told me about, rr, and another about server-side vs. client-side rendering.

Of course, this does not mean that I will interrupt this blog, on the contrary.

Investigating the last crashes on Shuttle

While I was in Brno, I tried to do some things remotely on Shuttle (specifically, installing and building emscripten tools for WebAssembly). It died on me.

Abort seems to indicate a true kernel issue, but with ominous warnings. The last two kernel crashes I had were marked as tainted. One had a bad page, the other a CPU stuck in Qemu for 23 seconds.

Abort does not report problems that are tainted. I wonder how many issues the kernel does never hear about because of that.

In any case, Shuttle is still not perfectly stable. Disabled Turbo Mode in the BIOS, hope it will help (doing one change at a time for obvious reasons).

A somewhat depressing graph

Below is the chart of my open-source contributions over time. It’s obvious that there is a big peak during the Taodyne times, and a few smaller peaks during the earlier years, when I was working on big changes in XL.

Screen Shot 2017-01-31 at 16.44.56.png

And then there was this instant drop in contributions starting in mid-2015. This was my time at DxO. I did not feel comfortable contributing anything serious to the free software community, because DxO and Tao3D were somewhat overlapping (image processing in both cases). Also, I did not have much time.

Time to catch up and put these numbers back up!

Spice on Linux build

When I was building from, network access was really incredibly slow. Much better now, I got a second build going. But it looks like jhbuild is re-fetching and re-building everything. That may not be my choice going forward.

Downloaded and built virt-viewer and virtglrenderer directly. Will test that as soon as I get a Tao that works so that I can test something else than glxgear inside a VM.


Setup a basic environment for WebAssembly, mostly out of curiosity. It’s like emscripten with a JavaScript-compatible bytecode.

The idea is interesting, but I don’t know if it will go anywhere. There’s so much overhead in the various layers involved that it hurts my head. I looked at the code generated for simple GL operations, and it is painful to watch (if smart, at times).

Yet, it makes for interesting demos. I want to see if I can run their little game demo within a VM and get reasonable results.

Tao3D build

I could not report during the week-end due to bad connexion, but I adjusted Tao3D to some recent changes. Mostly (documented in a previous entry):

  • LLVM has broken the API once again.
  • GCC recent changes have made it incompatible with how Qt deals with system include paths (uses of -isystem option). This breaks the VLC viewer.
  • The VLC team has also deprecated the function that returns FPS. But I’ve not found an acceptable replacement for it, so I stick with it for now. It’s used by Tao3D to compute the result of the movie_time function.

In VMware, the resulting Tao shows a black screen, though. It’s curious, because I have no error message whatsoever. The text editor works, but the menus also show black. I need to reproduce the build on a physical machine, see if the problem is with GL emulation in VMware. I’ve tested that glxgears works, but not much more.


Author: Christophe de Dinechin

I try to change the world, but that's work in progress. If you want to know me, google "Christophe de Dinechin". Keywords: concept programming, virtualization, OS design, programming languages, video games, 3D, modern physics. Some stuff I did that I'm proud of: the first "true" 3D game for the PC, HP's big iron virtualization, real-time test systems for car electronics, some of the best games for the HP48 calculator, a theory of physics that makes sense (at least to me).

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