Free RTOS heap usage

HI, I am using free rtos on STM32 M0 controller. I have defined configTOTALHEAPSIZE ( ( size_t ) ( 6500 ) ). I have created 4 task with 128 bytes stack each, 2 queues of length 10 and 2 mutexs. I want to know the heap used for this configurations. So I used the function xPortGetFreeHeapSize(). But this function returns 2924 value. I am a little confused as to how iam consuming (6500 – 2924 = 3576) Can anyone please explain? Thanks!

Free RTOS heap usage

Hi, To add to the above, I am using heap_4.

Free RTOS heap usage

I would expect there to be approximately 5K remaining – minus however much storage the queues are using. You say the queues or of length 10, but 10 what? 10 bytes?