Test of the Preemptive Kernel Patch

e8johan writes "Linux was originally written as a general-purpose operating system without any consideration for real-time applications. Recently Linux has become attractive to the real-time community due to its low cost and open standards. In order to make it more practical for the real-time community, patches have been written to affect such things as interrupt latency and context switch. These patches are public domain and are becoming part of the main Linux tree. The test results can be found here."

Comments

title

[tps12]

Is it just me, or does the title of this story sound like a Harry Potter book?

Amiga

[jafuser]

How did the Amiga Operating System rate on this matter? It always seemed to be very responsive even when heavily loaded down...

Real time linux vs. WinCE .NET

[OldMiner]

Since we recently had a nearly formal debate about this matter in my operating systems class, I thought I'd post some of the information I dug up comparing Windows and Linux (specifically in the embedded environment).

• WinCE .NET/WinXP Embedded XP Embedded is not practical for many applications, not the least of reasons for this being that it has no real time support and only runs on x86 processors. So if you want to go Windows and RT, you have to use WinCE
• Pricing Finding information about the price for WinCE is mildly difficult. I couldn't find any rates published on the web, but instead a list of suppliers. A called one and asked. About $2,663 for the original license and developer software wuth about $14 per copy of WinCE. I honestly doubt this would significantly impact the cost of any development.
• Development Code for WinCE generally has to be specially developed for WinCE; it can not be recycled from other Windows apps. Non-real time linux applications can normally be used directly in a linux RT environment.
• Worst-case latency WinCE apparently had a worst case latency of 30.8 microseconds on an x86 according to a somewhat dense report listed on Microsoft's website. Granted, an x86 is a somewhat unfair platform on which to test anything's latency. According to one maker of a real time linux system, latency is about 15 microseconds. The article for this story, however, finds a worst-case latency on a PowerPC to be on the order of .48 milliseconds or 480 microseconds. Ouch. That's pretty bad.