I started to play around with this properly last night and it was straightforward, fortunately. Did initially attempt to backport to 6.15 but it was a victim of some mm refactoring and didn't seem worth to carry on w/ that route. Started a rough page with notes for myself (but corrections & such welcome) at https://wiki.gentoo.org/wiki/Project:Toolchain/SFrame but honestly, it's immediately obvious (and beautiful) when it's working correctly. I've used Namhyung Kim's example from this thread but you can see it easily with `perf top -g` too. In one of the commit messages in the perf series, Steven also gave `perf record -g -vv true` which was convenient for making sure it's correctly discovered deferred unwinding support. I plan on doing measurements next and doing some more playing once I've built more userland with it.
