topic Re: IMXRT1170 dynamic memory allocation in i.MX Processors

IMXRT1170 dynamic memory allocation

ahmedhrabi — Wed, 27 Jul 2022 11:34:22 GMT

Hello All,

I'am testing dynamic memory usage on imxrt1176 on baremetal. When using standard C malloc() then free() functions, the allocated space is not released with the free function. The heap do not decrease:

Regards,

Ahmed.

Re: IMXRT1170 dynamic memory allocation

jeremyzhou — Thu, 28 Jul 2022 07:29:40 GMT

Hi,
Thank you for your interest in NXP Semiconductor products and for the opportunity to serve you.
In basic, I replicate the phenomenon you mentioned, further, I use the below code to find that MCUXpreso IDE can display the increasing heap usage.
I'll report the phenomenon to the IDE team for further checking soon later.

for(uint32_t i = 1; i < 5; i++) { int *array = (int*)malloc(32*sizeof(int)*i); if (NULL == array) { return -1; } free(array); array = NULL; }

Have a great day,
TIC

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Re: IMXRT1170 dynamic memory allocation

jeremyzhou — Tue, 02 Aug 2022 03:25:48 GMT

Hi @ahmedhrabi ，

There's the feedback from the AE team.

The Usage of 'Heap and Stack Usage' displays the maximum value which allocated, the usage value will update when the current allocated space larger than the previous allocated space, not update when the current allocated space smaller than the previous allocated space. In fact, the allocated space is released with the free function.

Some test results is below:

(1) array = (int*)malloc(50* sizeof(int)); the Usage displays 5.18%.

(2) array = (int*)malloc(200* sizeof(int)); the Usage will update as 19.82%.

(3) array = (int*)malloc(50* sizeof(int)); the Usage will remain as 19.82%, which is consistent with the applied maximum space before.

Have a great day,
TIC

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