Max messages in Message Queue

Aleix Conchillo Flaqué aconchillo at
Tue Jun 16 07:45:43 UTC 2009

On Tue, Jun 16, 2009 at 09:20, Samuel Bitton<S.Bitton at> wrote:
> It cannot be too many queues as I can create the queue ok with 100
> messages in it.
> Note that I get the error when I call create with 500 messages.
> Also note that I don't think it is a memory issue as for 100 messages
> the message size is set to 33 bytes and for the 500 messages case, I set
> the message size to 5 bytes only. So in theory this would require as
> much memory (unless RTEMS uses a lot of overhead on a per message
> bases).
> So to me there is a limiting factor for the number of messages per
> queue?

I'm not sure if this will be the problem, but if you are running 4.7
or older you might need to setup CONFIGURE_MEMORY_OVERHEAD which adds
space in the workspace for message queue buffers. Buffers are not
taken into account when reserving memory for message queues.


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