[$] Lockless patterns: some final topics

So far, this series has covered five common lockless patterns in the Linux
kernel; those are probably the five that you will most likely encounter
when working
on Linux. Throughout this series, some details have been left out and some
simplifications were made in the name of clarity. In this final
installment, I will sort out some of these loose ends and try to answer
what is arguably the
most important question of all: when should you use the lockless
patterns that have been described here?