Re: [ECOS] Max number of priorities using mlqueue scheduler

[Jonathan Larmour <jifl at eCosCentric dot com>]

Daniel Lidsten wrote:
> Hi,
>
> I am currently in the position where i need more priority levels than is
> specified in the "legal values" of the mlqueue scheduler. Is it possible
> to just increase the max legal value and then  set
> CYGNUM_KERNEL_SCHED_PRIORITIES to the number of priorities needed?
>
> I found an old post regarding this:
> http://sources.redhat.com/ml/ecos-discuss/2002-01/msg00440.html

Good for you for looking!

> It says something about a complication due to the bitmap scheduler. Is
> this still applicable to the newest source?

It's not the bitmap scheduler. It's a bitmap field used to record 
priorities, and it's a 32-bit integer, hence 32 priorities. If you editted 
the source you could change it to a cyg_uint64 and therefore it would be 
64 priorities, although that means "long long"s which means a small amount 
of extra overhead any time you do anything.

More than 64 distinct priorities would require something much more radical.

Jifl
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