MontaVista unveils "open" hard-real-time Linux project (LinuxDevices)

MontaVista unveils "open" hard-real-time Linux project (LinuxDevices)

Posted Oct 13, 2004 12:54 UTC (Wed) by simlo (subscriber, #10866)
In reply to: MontaVista unveils "open" hard-real-time Linux project (LinuxDevices) by hppnq
Parent article: MontaVista unveils "open" hard-real-time Linux project (LinuxDevices)

As I said, by using abstractions like the one Igno Molnar have used there is close to no problems of maintance. The basic way of using locks is the same in both cases. What should be done is that on Linus' tree everything tested for the "traditional" setup where spinlocks are used in most places. Then a company like MontaVista can configure their system to use mutexes instead and test that.

The important thing is that the code is the same but only different configurations are used. That would ease the patching and it will not destroy the time sharing properties of the 90% of the direct users. (If Linux is made real time and used in embedded enviroments the number of actual users in that segment would soon equal the number of users on servers and workstations.)

I agree that when you look at the real-time part of a system, it needs far less functionality than a time sharing system - and even if the further functionality is available it you must not use it as it will destroy your real-time properties! However, in a lot of cases you one part of the system having real-time properties and the other part having traditional time sharing properties. A good solution would be to have two CPUs and two OSes. But that is expensive in both hardware and development resources as the developers would have to know and maintain two completely different OS'es.

Where I work the result is that the management force us to put typical sharing applications onto a real-time OS which can not really support it. The main argument is that we don't have development resources to maintain two OS'es for our processor boards.

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