I find the subject of fault tolerance and resiliency in computers quite interesting. It also very interesting to look into what kinds of faults actually do happen in the real world, and what impact they have. I recently found a couple of good sources on this. First of all, a paper from Super Computing 2012 by Fiala et al, called “Detection and Correction of Silent Data Corruption for Large-Scale High-Performance Computing” (ACM Digital Library). One of its references was to a 2011 talk by Al Geist, “What is the Monster in the Closet”, which provided some more data on how common faults are.
There is a new post at my Wind River blog, an interview with Andreas Buchwieser from the Wind River office in München. It discusses how Simics can be applied to the field of safety-critical systems, including helping test the software to get it certified. Really interesting, and in particular it is worth noting that qualifying tools in the IEC 61508 and ISO 26262 context is much easier than in DO-178B/C. The industrial family of safety standards have been created to allow for tools to help validate an application without forcing incredibly high demands on the development of those tools.
There is a new post at my Wind River blog, about how Simics is used to simulate large wireless networks for IoT (Internet-of-Things) applications.
It is funny for me to be back at the IoT game. A decade ago (time flies, doesn’t it?), at Virtutech, I and Johan Runeson took part in an EU research project on exactly this topic. Unfortunately, we had to back out of that project due to economic circumstances and failing management commitment, but we still learnt a few things that were relevant now that we are back in the IoT game. In particular, how to simulate wireless networks in a reasonable way in a transaction-level simulator. Thus, payback for the investment took 10 years to arrive, but it did arrive. To me, that underscores the need to be a bit speculative, take some risk, and try to explore the future.
I am going to be speaking at the 2015 Embedded World Conference in Nürnberg, Germany. My talk is about Continuous Integration for embedded systems, and in particular how to enable it using simulation technology such as Simics.
My talk is at 16.00 to 16.30, in session 03/II, Software Quality I – Design & Verification Methods.
I am using the “Webex productivity tools” at work to quickly schedule and start meetings from within Outlook. It really is a very useful piece of software for those of us that do quite a few Webex conferences each week. However, it came with one annoying side effect: little webex tabs started to appear on select application windows. In particular, on top of Skype windows.
When mobile phones first appeared, they were powered by very simple cores like the venerable ARM7 and later the ARM9. Low clock frequencies, zero microarchitectural sophistication, sufficient for the job. In recent years, as smartphones have come into their own as the most important computing device for most people, the processor performance of mobile phones have increased tremendously. Today, cutting-edge phones and tablets contain four or eight cores, running at clock frequencies well above 2 gigahertz. The performance race for most of the market (more about that in a moment) was mostly about pushing higher clock frequencies and more cores, even while microarchitecture was left comparatively simple. Mobile meant “fairly simple”, and IPC was nowhere near what you would get with a typical Intel processor for a laptop or desktop.
Today, that seems to be changing, as the Nvidia Denver core and Apple’s Cyclone core both go the route of a few fat cores rather than many thin cores.