Mar 042014
 

This post originally appeared on the Flux7 blog at: http://flux7.com/blogs/benchmarks/littles-law/. It discusses the relationship between throughput and latency summarized by Little’s Law. Little’s Law has applications on any system with throughput and latency, whether it is memory performance or an industrial assembly line. Read the original article below:

Continue reading “Understanding Throughput and Latency Using Little’s Law” »

Apr 012013
 

In the second part of the series we introduced memory management and interrupt handling support provided by virtualization hardware extensions. But effective virtualization solutions need to reach beyond the core to communicate with peripheral devices. In this post we discuss the various techniques used for virtualizing I/O, the problems faced, and the hardware solutions to mitigate these problems.

Continue reading “ARM Virtualization – I/O Virtualization (Part 3)” »

Mar 242013
 

In the first part of this series, I introduced the topic of virtualization. Today I will venture deeper into the ARM virtualization extensions for memory management and handling of interrupts. Within the core, virtualization mostly provides controls over the system registers. But as we move further from the core, and start to communicate with the outside world, difficulties and nuances in the problem start to emerge and the need for hardware support for virtualization becomes apparent.

Continue reading “ARM Virtualization Extensions – Memory and Interrupts (Part 2)” »

Mar 182013
 

Sorry guys for another hiatus, my job at Calxeda keeps me busy. I was recently discussing ARM’s virtualization support with my friend Ali Hussain (yup, that’s our idea of a fun dinner conversation) and found some very interesting facts. I requested Ali to share his knowledge in a blog post series on this topic, so here you go. Ali is in ARM’s performance modeling team and has been working on ARM cores since 2008.

The idea for this blog post stemmed from talking to people that had the impression that ARM’s virtualization support, even with the virtualization extensions in Cortex-A15, is limited. I plan to write a few posts exploring virtualization, and the support for it in the ARM and x86 ISAs. This post will draw heavily on my understanding of the ARM architecture and operating systems.

Continue reading “ARM Virtualization Extensions — Introduction (Part 1)” »