LKML is scary and forbidding.
You're suggesting i wander into a contentious topic and start opinionating?
I am a Linux user who does, among other things, systems performance tuning. I do this ad hoc and also as a significant portion of my job. Luckily I have the freedom to do portions of my work on Solaris, where dtrace is accessible. Unfortunately the Solaris internals are generally less well documented or at least less familiar than Linux to me.