Messages in this thread | | | From | Jochen Karrer <> | Subject | Re: Preempting kernel tasks | Date | Fri, 6 Sep 1996 15:08:30 +0200 (MET DST) |
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On Thu, 5 Sep 1996, Linus Torvalds wrote:
> Like David, I do not like the idea of pre-empting kernel tasks. It implies a > more complex locking setup than I'd really like.
I think any realtime task should be able to preempt the kernel, while the realtime task executes code in the USER-SEGMENT. If the task does a System call, the control has to be given back to the task, which holds the kernel lock. This would give a very fast response which is required by realtime tasks, if the realtime-task uses locked memory.
I think this change should cause no problems. As far as I know its already possible to execute code in a tasks User Segment while a second processor executes Kernel-Code in SMP-Linux, so why not doing something similar with a single processor ?
> HOWEVER, I'm all for having "user processes" in kernel mode. That's not too > hard - if only implies that we have to change the way we test for "user vs > kernel" a bit.
This in combination with my above suggestion would make possible very nice realtime tasks.
What do You think about this ?
Jochen
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Jochen Karrer http://cip.physik.uni-wuerzburg.de/~cip307
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