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David, |
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I am also a relatively happy user of Timesys. Actually their toolchain, |
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libraries, and even thier optomized kernel are all free from thier website. |
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What will cost you is the RTOS extendsions, and the IDE which is very nice |
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and build on top of eclipse. Also they have decent support for some |
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questions. I have benchmarked thier kernel verses the vanilla kernel and |
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thier latencies are considerably lower. I believe they have a paper about |
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this on thier website also. (I do embedded video systems, their kernel had |
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firm enough latencies that we decided that we did not need the RT |
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extensions) |
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|
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Austin Morgan |
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|
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-----Original Message----- |
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From: David |
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To: gentoo-embedded@l.g.o |
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Sent: 5/12/2005 5:58 PM |
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Subject: Re: [gentoo-embedded] real time linux |
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|
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>How do I no if need a real time OS? |
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|
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Ask yourself the following questions: |
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Do you have hard real-time constraints? i.e. |
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Do you have a task that needs to run exactly every nth millisecond |
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(or microseconds)? |
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Do you have tasks that must run in under n milliseconds, every time? |
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Do you need to be able to determine and rely on the maximum time a |
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task may take? |
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|
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If you answered yes to any of these questions you need a real-time |
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system. |
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|
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I used milliseconds in the questions above, although technically |
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speaking, any time deadline (seconds, minutes, hours, days...) could be |
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considered a real-time constraint. However if your deadlines are that |
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long you probably don't need real-time capabilities. |
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|
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And Heath, you are correct, stock Linux (even embedded) is not an RTOS. |
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|
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There are real-time linuxes (?) out there that purport to support hard, |
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real-time constraints (eg timesys) similar to Lynx, vxWorks or |
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Integrity. I have worked with people who were using timesys's linux, |
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and they were largely happy with the performance (latency). I believe |
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you can get the timesys libraries for free, but the toolchains (cross |
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compiler, linker...) will cost you. There are free distros claiming |
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real-time, but I cannot comment on their performance. |
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|
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David |
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|
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|
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Francisco Ares wrote: |
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|
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>Anything in portage? Could not find it yet. |
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> |
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>And I have some doubts, if anyone could point me to some links, |
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>specially benchmarks, I would really appreciate: |
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> |
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>How do I no if need a real time OS? |
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>Should I rely only on the preemptibility of the 2.6 kernels? |
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>Which real time Linux flavor is best for which types of applications? |
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> |
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> |
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>Thanks a lot |
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>Francisco |
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> |
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> |
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> |
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-- |
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gentoo-embedded@g.o mailing list |
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