Re: Best Kernel Timers?

[Christoph Lameter]

On Wed, 28 Sep 2005, Simon White wrote:

> Now as an alternative it is again desired that a version (although
> wont perfectly work) be available to a vanilla 2.6 kernel (possibly
> 2.4) with similiar limitations as before.  Its a shame the posix
> calls appear to not be supported in kernel for drivers so I have
> wrapped the calls for semaphores/mutexs/threads to kernel
> equivalents.

They are supported. See drivers/char/mmtimer.c for an example 
implementation.

> However I have no idea what to do for the timers.  Is there
> something suitable inkernel that would provide an async callback
> to pre-empt a realtime thread and provide better resolution than
> HZ a far amount of the time?  Or do I have to run a seperate lower
> priority busy waiting thread to wakeup the realtime one?

Yes. Provide an implementation for a posix clock like done in the mmtimer 
driver.
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