>I'm not sure I see much good in integrating non-kernel stuff into the kernel tree, but I wonder if it would make more sense if some of these tools were perceived as test tools comprising part of a kernel test suite.
I think this is very interesting idea and replying & quoting this just to raise attention and some insightful consideration for it.
The article raised a question, why perf is deemed to indefinite life in the kernel tree? As I have considered perf to be a kernel performance tool for kernel developers and haven't yet seen the userspace tools I use to monitor and tune system performance to use perf for anything, I haven't payed much attention to it. Does perf's life in kernel tree and the perception hinder its worthyness and development of use in userspace? Thus a kernel test & ABI suite/tree like linux-next but to reverse direction seems logical from a sysadmin perspective.