On Thu, Oct 14, 2021 at 09:58:39PM -0500, madvenka@linux.microsoft.com wrote:
> From: "Madhavan T. Venkataraman" <madvenka@linux.microsoft.com>
> 
> Currently, get_wchan() in ARM64 code walks the stack using start_backtrace()
> and unwind_frame(). Make it use arch_stack_walk() instead. This makes
> maintenance easier.

This overlaps with some very similar updates that Peter Zijlstra is
working on which addresses some existing problems with wchan:

	https://lore.kernel.org/all/20211008111527.438276127@infradead.org/

It probably makes sense for you to coordinate with Peter here, some of
that series is already merged up to his patch 6 which looks very
similar to what you've got here.  In that thread you'll see that Mark
Rutland spotted an issue with the handling of __switch_to() on arm64
which probably also applies to your change.