Hi, I am currently trying to trace the execution of multiple cores without affecting too much the behavior of the running program. This obviously requires to manage a shared resource in the trace macros (e.g. a UART peripheral) so it would require to define the trace sections as critical before acqu…

My first thought is that directly logging to the UART is just not going to be feasible due to the contention you mention. I would probably give each core its own area of memory to record logging information (perhaps a log record includes where the other processor was in its logging area), and then h…

That was my backup plan too, however I was keeping it as last resort because it needs to be adapted too much to the traced program. Moreover, if the program implements a periodic schedule I still need to ensure the core that frees the log buffers is the only one accessing them, otherwise every now a…

Serialize the traces to ownership of the UART is going to be a much bigger effect than to in memory core buffers, and. as you point out can lead to deadlock if you are not careful. You don’t “free” the log buffers, they are statically allocated as a circular buffer, and there are way to use them th…

Your initial requirement is a contradiction in terms. It is a well known fact that serial debugging significantly changes the run time behavior, frequently to the degree that problems that show without it do not show with it and vice versa. The enforced serialization is only one aspect of it. I wil…

Thank you, I get what you are saying, I just though that having “small” critical sections in some parts of the code would have had a minor impact on the execution than having a bigger time slot where a core access to a shared resource (i.e. other cores’ buffers) to read it and output everything over…

Thank you for the suggestion. I do not have a lot of experience in tracing the execution without a debugger (no error happens while doing instruction step) but I was trying to see if what I described before was doable as it needs less program-specific adjustments.

You may want to explore Tracelyzer which supports SMP - Multicore Tracing on FreeRTOS 11 and TI AM62x - Percepio .

Thank you, I was aware of it but I am working on my thesis and unless my university agrees to fund it I cannot afford any third-party software that is not free.

Thanks a lot, I didn’t know there was a “lite” version.

FreeRTOS SMP: trace the execution of multiple cores

Kernel

aggarg (Gaurav Aggarwal) April 9, 2025, 11:47am 10

Percepio recently released a limited capability version that is free - New free trace tool from Percepio.

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FreeRTOS SMP: trace the execution of multiple cores

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