On Tue, Aug 29, 2017 at 07:57:20AM +0200, Vincent Bernat wrote:
Feedback appreciated! (Better ideas also appreciated. :D)
Using USDT probes? You can attach arbitrary strings to them. I know perf supports them (with a recent kernel) but I don't know how exactly. However, with systemtap, it's dead easy to see them:
stap -e 'probe bird.* { print($$vars) }'
For implementation, see: https://github.com/vincentbernat/lldpd/commit/bdfe419389075af3cdfeadc78008a1... https://github.com/vincentbernat/lldpd/commit/140e34f057462d5ff7818ab4af368f...
As far as I can see, these are tracepoints, but they wouldn't let me do profiling? What I need is profiling, as I want to know what's consuming the most CPU, so I want to be able to fire an event N times per second to tell me what bird is doing right at that specific moment, and listing or counting tracepoint invocations won't necessarily tell me what's using up the most CPU.