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LinuxDevices.com: Preemptible Linux -- a reality check

Sep 06, 2001, 20:46 (2 Talkback[s])

[ Thanks to Anon for this link. ]

"Some oppose a preemptible kernel because of throughput concerns. Others oppose preemptibility because of concerns about growing complexity in the kernel. This argument is specious, because the preemption approach takes advantage of already required and in place SMP locking. No additional complexity is created. All Linux kernel engineering must already take into account SMP requirements. Some oppose continued refinement of SMP locking to achieve better SMP scaling (on higher way SMP systems); such refinement has the beneficial side effect of also reducing preemption off periods in a preemptible kernel.

Preemptibility on 2.4 already provides dramatic improvements in user process responsiveness, and while further improvement would be beneficial, the current level of improvement is already of tremendous value. Hence, the pro's and con's of improving SMP scaling in Linux can be debated relatively independently of preemptibility improvement opportunities.

Embedded Linux companies have responsibilities to the open source and Linux communities, as well as to the embedded system product development communities. They have a responsibility to innovate and release innovations early and often, for public comment and contribution. They have a corporate responsibility to do their best to enable Linux to be a viable operating system platform for embedded system design and implementation. Their customers also will find significant value in the exercise of that responsibility, through the delivery of such product technologies as a preemptible Linux kernel."

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