In the past year, I have started listening to various podcast from the “Skeptic” community. Although much of the discussion tends to center on medicine (because of the sadly enormous market for quackery) and natural science (because the sad fight over evolution), it has made me think and reflect more about the nature of science and publishing. Indeed, it would have been great if this kind of material would have been easily found back when I was doing my PhD.
Author: Jakob
Speaking at Embedded Conference Scandinavia
I am going to be talking about how to transport bugs with virtual platform checkpoints, in the Software Tools track at the Embedded Conference Scandinavia, on October 3, 2012, in Stockholm (Sweden). The ECS is a nice event, and there are several tracks to choose from both on October 2 and October 3. In addition to the tracks, Jan Bosch from Chalmers is going to present a keynote that I am sure will be very entertaining (see my notes from a presentation he did in Göteborg last year).
Wind River Blog: Testing Multicore Scaling with a Simics QSP
A few years ago, I built a demo on Simics that used a hacked Freescale MPC8641D target that was forced to scale from 1 to 8 cores. Some interesting experiements could be made using this target, and it was nicely scalable for its time. However, I always wanted to have something just a bit bigger. Say 20 cores, or 100. Just to see what would happen. Finally, I got it.
The Simics QSP target that we quietly launched earlier this Summer is such a scalable target. As discussed in a blog post describing the architecture, it is designed to scale to 128 cores currently. Using this ability, I repeated my old experiments, but trying very large threads counts and target core counts. The results show clearly that the way that I coded my parallel computation program was pretty bad, and I really would like to try to rewrite it using some more modern threading library. All I need is time and a way to cross-compile Wool…
Anyway, the new blog post is here.
Speaking at SiCS Multicore Day 2012
I am scheduled to talk at the SiCS multicore day 2012 (like I did back in 2009 and 2008). The event takes palce on September 13, at SiCS in Kista. My topic will be on System-Level Debug – how we can make debuggers that work for big systems.
This year, the multicore day is part of a bigger Software Week event, which also covers cloud and internet of things. See you there!
Buying High Technology
Selling and marketing high technology is what I do for a living. My counterpart is the customer or buyer, and I help design, build, explain, an market these products. In this role, I am most usually the expert on the domain, helping potential customers understand what we sell and why it will help them. Both at the high-level value proposition and the details behind it. Some people focus most of the their energy on the high-level value proposition, but I feel that youoften need a bit detail backing that as well.
I recently had the enlightening experience of being on the buying side instead, experiencing the transition from high-level value proposition to low-level details. It struck me as being quite similar to what the customers for our virtual platforms would experience when coming in new to the field.
I bought a camera.
“Eagle” Cycle-Accurate Simulator Anno 1979
I recently read the classic book The Soul of a New Machine by Tracy Kidder. Even though it describes the project to build a machine that was launched more than 30 years ago, the story is still fresh and familiar. Corporate intrigue, managing difficult people, clever engineering, high pressure, all familiar ingredients in computing today just as it was back then. With my interesting in computer history and simulation, I was delighted to actually find a simulator in the story too! It was a cycle-accurate simulator of the design, programmed in 1979.
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Some Fun Cache Results from Carbon
Carbon Design Systems have been on a veritable blogging spree recently, pushing out a large number of posts around various topics. Maybe a bit brief for my taste in most cases (I have a tendency to throw out 1000+ word pseudo-articles when I take the time to write a blog), but sometimes very interesting nevertheless. I particularly liked a few posts on cache analysis, as they presented some good insight into not-quite-expected processor and cache behaviors.
Wind River Blog: Inside the Simics QSP – Additional Notes
There is a new post at my Wind River blog, about the design and technical contents of the new Simics Quick Start Platforms, more widely known as the QSP. The blog describes the virtual-only hardware that forms part of the QSP, and how it was designed. It is interesting to note that the hardware ended up a bit more complex that I initially thought it would be, since an ideal virtual platform should be very simple. Right? Turns out an OS complicates things.
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Off-topic: Society without God
I just finished reading Society without God, by American sociologist Phil Zuckerman. The book came out back in 2008, but I heard about it recently on a skeptic podcast and I felt I just had to buy it. Phil Zuckerman spent a year in Denmark in 2006, and also visited Sweden during that time to perform interviews with a wide sample of what seems to me to be typical Swedes and Danes, trying to understand their attitude towards god and religion. His conclusion is that the Nordic countries today are a special little area of deep secularism in a world that is mostly religious and apparently growing more religious recently. Even in fairly secularized Western Europe, the Nordic countries stand out (or at least Denmark and Sweden does, in his research). So what? For a Swede like myself this is pretty obvious… but when you combine this with the fact that the standard of living and overall feeling of security and quality of life in Denmark and Sweden is very high, Zuckerman finds a great argument against a certain argument brought forth by Christian conservatives in the US…
Youtube Movie on Reverse Execution (and a small bit of Reverse Debug)
We just uploaded a short movie about reverse execution and reverse debugging to Youtube, to the Wind River official channel. In the short time available in this demo, we really only show reverse execution. Reverse debug, as I define it, is not used much at all, as explaining what goes on when you start to put breakpoints into a program and analyze its behavior takes a surprising amount of time.
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Building a Spy-Proof OS?
I am not in the computer security business really, but I find the topic very interesting. The recent wide coverage and analysis of the Flame malware has been fascinating to follow. It is incredibly scary to see a “well-resourced (probably Western) nation-state” develop this kind of spyware, following on the confirmation that Stuxnet was made in the US (and Israel).
In any case, regardless of the resources behind the creation of such malware, one wonders if it could not be a bit more contained with a different way to structure our operating systems. In particular, Flame’s use of microphones, webcams, bluetooth, and screenshots to spy on users should be containable. Basically, wouldn’t cell-phone style sandboxing and capabilities settings make sense for a desktop OS too?
Off-Topic: Analyzing Outlook Mailbox Size
Where I work, we use Exchange as our email server and Outlook as the primary client (at least I do). We also have an email quota that I keep bumping into, since I have a tendency to attract many emails with large attachments like image-happy PowerPoint files or binary code modules to patch things. I am also an extreme user of email folders. My main Outlook account contains some 650 folders, and my offline archive of all my old emails reaches towards 1300, with many 100s of thousands of emails for a total of almost 20 GB. So, pretty extreme.
My problem is: what do I do when the email system tells me (and it is serious, I can attest) that I am close to hitting my quota and that soon email will neither be received nor sent? I want to find the folders that are very large and candidates for some archiving. The answer has eluded me for a long time, until I stumbled upon a 2010 Youtube video: http://www.youtube.com/watch?v=3skJOd4GIak, from “tech-informer.com” (which now looks pretty dead). With some modifications, this solved my problem.
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Wind River Blog: Teaching Networking with Simics
On the Wind River corporate blog, I have put up a blog post about how Wind River Education Services is going to use Simics to teach networking. What is interesting with this approach is that it shows how a virtual platform can be used for tasks like teaching that don’t have much to do with hardware modeling or similar “typical” VP uses. In this case, the key value is encapsulation of a set of machines running real operating systems and software stacks, and with lots of networks connecting them.
IBM Mainframe: Parallelism as Patch
When IBM moved their mainframe systems (the S/360 family that is today called System Z) from BiCMOS to mainstream CMOS in 1994, the net result was a severe loss in clock frequency and thus single-processor performance. Still, the move had to be done, since CMOS would scale much better into the future. As a result, IBM introduced additional parallelism to the system in order to maintain performance parity. Parallelism as a patch, essentially.
Wind River Blog: Forcing Rare Bugs to Appear using Simics
There is a new post at my Wind River blog, about how a team of researchers at the University of Nebraska at Lincoln is using Simics to force rare bugs to manifest themselves as errors. They used Simics to control a target system to force it into rare situations much more likely to trigger latent bugs, requiring far fewer test runs compared to just randomly rerunning tests again and again and hoping to see a bug.