RFC: Initializing and placement of thread/fiber/task stacks

Mitsis, Peter <Peter.Mitsis@...>

Any objections/comments to the following?

Thread stacks (as defined by the __stack attribute) should be placed into their own section. By default this section should be a part of the .noinit section so that they do not impact run time performance. However, if the Kconfig option INIT_STACKS is enabled, then the stacks should be placed into their own unique section and their stack space should be initialized at boot time to a known value (0xaa).

Although this will result in a longer boot time (when INIT_STACKS) is enabled, it means that aside from the potential boot time penalty, there is never a stack initialization run time penalty when creating a thread. This may be particularly beneficial should a thread be restarted or thread-space be reused as the stack will not be re-initialized. Note that this changes the semantics of thread stack usage to mean thread stack usage for all threads that use that stack.

Peter Mitsis

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