On Mon, Aug 5, 2013 at 10:55 AM, Steven Rostedt <rost...@goodmis.org> wrote: > > My main concern is with tracepoints. Which on 90% (or more) of systems > running Linux, is completely off, and basically just dead code, until > someone wants to see what's happening and enables them.
The static_key_false() approach with minimal inlining sounds like a much better approach overall. Sure, it might add a call/ret, but it adds it to just the unlikely tracepoint taken path. Of course, it would be good to optimize static_key_false() itself - right now those static key jumps are always five bytes, and while they get nopped out, it would still be nice if there was some way to have just a two-byte nop (turning into a short branch) *if* we can reach another jump that way..For small functions that would be lovely. Oh well. Linus