a problem about using message queue in dsplink

Hi,
I have a problem in minimizing the time dsplink uses in communication.
According to the elapsed time calculated from CLK_gethtime(), i find
out function message_put() may use up to about 30us. Under tsk mode,
message_get() may use up to about 30us; while under swi mode, calling
the callback function may also use up to about 30us. The same amount of
time can be observed under both message and buffer transfer.
As the time delay does not always present in the system, I think this
may be caused by some racing issue that puts the dsp side into a spin
lock.
Is it possible to reduce the maximal possible time delay in dsplink
data transfer? Or can I use dsplink in a way that it does not lock dsp
for so long a time?
Thank you for your kind attention.