Hi all, We've been thinking about some memory optimizations for which it might be easier if our own code provided the stack memory for newly created ULTs so that we have full control over the allocation strategy. This seems pretty straightforward with the ABT_thread_attr_set_stack() function: https://www.argobots.org/doxygen/latest/d2/df6/group__ULT__ATTR.html#gac8f39... However, our use case often creates unnamed (detached) threads by setting the ABT_thread_create() newthread argument to NULL. I can elaborate if needed, but the short story is that this is a really natural fit for RPC handlers in our model: https://www.argobots.org/doxygen/latest/d0/d6d/group__ULT.html#ga73bd1f04ce5... Is it possible to do both (provide an externally managed stack pointer, and use unnamed ULTs)? From the documentation it looks like the answer is probably no, because the caller who created the stack allocation doesn't explicitly free the ULT, and thus doesn't have a way to free the stack after the ULT is complete. I wanted to double check though before I start thinking about alternatives, though. thanks! -Phil