When the tidl object detection demo is run, and the perf-stats are printed during the run, the following is seen.

CPU:  c7x_1: HEAP:    DDR_LOCAL_MEM: size =  268435456 B, free =  239318272 B ( 89 % unused)
CPU:  c7x_1: HEAP:           L3_MEM: size =    8159232 B, free =          0 B (  0 % unused)
CPU:  c7x_1: HEAP:           L2_MEM: size =     458752 B, free =     458752 B (100 % unused)
CPU:  c7x_1: HEAP:           L1_MEM: size =      16384 B, free =          0 B (  0 % unused)
CPU:  c7x_1: HEAP:  DDR_SCRATCH_MEM: size =  385875968 B, free =  382257093 B ( 99 % unused)

Here the L2_MEM and L3_MEM are used as scratch memory by the TIDL.

Yet, L2_MEM is being shown as 100% unused.