Messages in this thread | | | Subject | Re: FP in kernelspace | From | Andi Kleen <> | Date | 30 Jul 2006 19:32:50 +0200 |
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Jiri Slaby <jirislaby@gmail.com> writes:
> I have a driver written for 2.4 + RT patches with FP support. I want > it to work in 2.6. How to implement FP? Has anybody developped some > "protocol" between KS and US yet? If not, could somebody point me, how > to do it the best -- with low latency. > The device doesn't generate irqs
Doesn't sound like something that should be supported for mainline then.
> So 2 questions are: > 1) howto FP in kernel
You can use kernel_fpu_begin()/_end() around the FP code in the kernel, but the real time people will probably hate you for it because it disables preemption.
> 3) any way to have faster ticks (up to 5000Hz)?
There are plenty of interval timers in various hardware in a typical system that can be used. e.g. RTC is a common choice. Drawback is that you might conflict with other users, especially in user space.
But please don't try to submit such a hack.
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