Multi-core

10 articles

Analyzing Manycore Scaling with Simics

In my previous blog post on multicore scaling investigations with Simics, I tested a simple parallel program on a variety of machines. The scaling obtained was not particularly impressive, especially not on a 60-core target machine. In this post, we will use the Simics timeline view to look a bit closer at what is going on inside the target machines.…

Testing Manycore Scaling with Simics

A few years ago, I did a Simics demo where I tested the scalability of a multithreaded program as the target hardware went from two to four to eight cores. Unfortunately, I could not take it beyond that point, since the hardware platform that I used simply did not allow for more than eight cores. Now, with the Simics Quick…

IMA on Simics: An Interview with Tennessee Carmel-Veilleux

After Summer, I have been in contact with Tennessee Carmel-Veilleux at the École de technologie supérieure in Quebec, who has been doing some really cool work with Simics.  Tennessee has learnt Simics very quickly, and has been very clever in how to apply Simics to the research problems he has encountered. In this interview, he tells us some more about…

Variable and Deterministic

A virtual platform like Wind River Simics is generally designed to be deterministic. Determinism brings a host of benefits to users (repeatability of bugs, reverse execution, bug transportation, etc.), but is also easily misunderstood. Quite often, users fear that they will lose an important "feature" of a physical machine - its built-in variation across runs of the same software. If…

Transporting Bugs with Checkpoints

I have a paper about "Transporting Bugs with Checkpoints" to be presented at the S4D (System, Software, SoC and Silicon Debug) conference in Southampton, UK, on September 15 and 16, 2010. The core concept presented is to leverage Wind River Simics checkpointing to capture and move a bug from the bug reporter to the responsible developer. It is a fairly…

Interview with Girish Venkatasubramanian

After my blog post on Academic Simics earlier this Summer, I got a very nice reply from Girish Venkatasubramanian of UFL. Turned out that he and his group was doing some really interesting and exciting stuff with Simics, researching into Hypervisor architectures and hardware support. Having been a PhD student myself, I can certainly appreciate the excitement and fun of…

Travelling into 64-bit Land with Simics

The new Freescale QorIQ P5020 SoC that was announced this week at the Freescale Technology Forum means that yet another chip family has now moved to 64 bits from 32 bits. This is a familiar scenario that has been played out many times before, starting in the mid-1990s as Sun, IBM and MIPS upgraded their server processor architectures to 64…

True Concurrency is Truly Different (Again)

A recent article at Ars Technica describes yet another security flaw in Windows. Nothing much new in that respect, but this is indeed an interesting attack in that it is enabled by using multicore hardware. It is not practical on a single processor, demonstrating once again how multicore is fundamentally different from multitasking on a single processor. 57

Analyzer Analyzed

The big news in Simics 4.4 is the new Simics Analyzer product. Analyzer contains a few different technologies, but the most immediately visible is the new execution timeline view. The timeline view shows the execution history of the software on the target system, making it easy to see what has run where and when. In this blog post, I will…

What is Simics, Really?

As you might have seen, Wind River recently acquired Simics, a product formerly sold by Virtutech. My colleagues Michel Genard and Bill Graham recently blogged on the topic.Simics can have a huge impact on the product development processes, time-to-market and quality. Apart from the cool things that Simics does to improve the development process, it is also a very interesting…