NetBurner Community Forum

Feedback solicitation time! I've got a feature I'm interested in implementing in the RTOS that should increase performance in applications with multiple stacks located in external memory. However, it would burn a potentially large amount of SRAM (and be unavailable on MCF5272 parts due to the SRAM limitations). It also would be, at best, completely useless for applications that have no stacks in external RAM (it would add ~10 instructions to the task switch code). What is missing from this question is any sort of knowledge as to how people actually use the OS and other libraries. To that end, I am seeking input from users for a) how many tasks in a normal application of theirs have the stacks in external memory, and b) what kind, if any, data collection would be acceptable from an installation.

On that second note, I'll elaborate on what kind of data I'd love to have. It would be awesome to see what people have their 'predef.h' and 'constants.h' set to. As these files control most aspects of the entire system they are fairly important. That said, it would be important to only look for the macros we expect to be there, not any that the user may have added. I don't have a specific notion for how this collection would be triggered, beyond using the C preprocessor to generate the data log. It would also be great to see what libraries people are actually using in their applications, but that one I feel is probably too intrusive to actually do. In any case, my inclination is to make any data collection entirely opt in, as opposed to opt out, and with potentially multiple levels. (I'm kind of a privacy/security person myself; I like to have control over what I share or don't share.)

What I'm looking to accomplish is to be able to better understand how y'all use our tools to make them better for you, in essence, automagically determining what you wanted without ever having to ask or you to even know you wanted it.

What are peoples' thoughts on the matter?

Would the polling feature of this forum be a better option for this type of question?

I for one have never used external memory for stacks. I didn't even realize it was possible. I've never had the need for a particullary large stack. I also don't modify consts.h or predef.h.

Poll added.

I realize a lot of people don't use external memory for stacks, but I have also heard of people running 10+ tasks, which I'm expecting would do so.

Interesting, I've been running 14 tasks and haven't had a need to use external memory for stacks yet. I think if I did get to that point I'd focus on minimizing my stack requirements than using external memory.

As for the data collection I don't like the idea of the automatic process, though I don't particularly mind volunteering some of that information.

I'm happy to share information. I use a lot of tasks and do have stacks in external memory. I'm all for anything that would make better use of this.

I don't modify predefs.h or constants.h. In fact, I avoid making ANY modifications to any system or library code that way it keeps doing upgrades of the NNDK tools very clean for me.

Would sharing the map files help? This gives a lot of the information I'd think you'd need and I don't really see it as disclosing anything sensitive for people.