Dynamic switching of co-processor context

[Peter Dufault]

On Oct 19, 2009, at 10:30 , Till Straumann wrote:

> This strategy seems reasonable under the assumption that a task
> who uses the co-processor once is likely to use it in the future  
> again.
> For tasks that 'always' use the co-processor it eliminates the need
> for handling an exception every time the task is given the CPU.

My problem with this is that a bug either in the compiler (generates  
floating point when it seems as if it shouldn't, something we're all  
familiar with), build flags, or in the task will let the thread just  
silently start incurring the additional context switch overhead from  
then on when you didn't expect it.  You could add a soft "And this  
thread is allowed to use the co-processor" flag to address that.

Peter