Messages in this thread | | | Subject | Re: [RFC PATCH 00/11] mcount tracing utility | From | (Frank Ch. Eigler) | Date | Fri, 04 Jan 2008 01:42:32 -0500 |
| |
Steven Rostedt <rostedt@goodmis.org> writes:
> The following patch series brings to vanilla Linux a bit of the RT kernel > trace facility. This incorporates the "-pg" profiling option of gcc > that will call the "mcount" function for all functions called in > the kernel. > [...] > [Future:] SystemTap: > ---------- > One thing that Arnaldo and I discussed last year was using systemtap to > add hooks into the kernel to start and stop tracing.
Sure. The dual of this makes sense too: letting systemtap scripts hook up to the mcount callback itself, for purposes beyond just tracing the function calls.
> kprobes is too heavy to do on all funtion calls, but it would be > perfect to add to non hot paths to start the tracer and stop the > tracer.
(Note that kprobes are not the only event sources systemtap can use: markers, timers, procfs control files, and some others. Any combination of these can be used in a script to express start/stop decisions.)
- FChE
| |