Slashdot Mirror
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."
Whenever you have to control a high speed process, you need real-time. No, it doesn't mean 'live', but instead it relates to situations where you have hard timing limits that you have to meat for things to even work. Single session CD-writing is a good example, if your application/OS combo doesn't meat the hard real-time deadlines related to how fast the physical disc is spinning, you've just wasted the media blank and have to start over. In many real-time applications, not meeting the timing can mean the equipment may be dammaged or destroyed, possibly in a manner dangerous to anyone standing around operating it. A lot of times it is more an issue of quality suffering, so real-time is more of a desirable target than an absolute necessity.
If these patches are applied when they aren't really needed, how much does it impact the system's performance and stability? I read in the thread shown that it conflicts with SMP, so you'd want it turned off for installs on multiprocessor systems, but aside from that, why can't it be turned on by default?