On Wed, 29 May 2019 11:31:23 +0200 Thomas Preisner <linux@xxxxxxxxxxxx> wrote: > The "oneshot" tracer records every address (ip, parent_ip) exactly once. > As a result, "oneshot" can be used to efficiently create kernel function > coverage/usage reports such as in undertaker-tailor[0]. > > In order to provide this functionality, "oneshot" uses a > configurable hashset for blacklisting already recorded addresses. This > way, no user space application is required to parse the function > tracer's output and to deactivate functions after they have been > recorded once. Additionally, the tracer's output is reduced to a bare > mininum so that it can be passed directly to undertaker-tailor. > > Further information regarding this oneshot function tracer can also be > found at [1]. > > [0]: https://undertaker.cs.fau.de > [1]: https://tpreisner.de/pub/ba-thesis.pdf > > Signed-off-by: Thomas Preisner <linux@xxxxxxxxxxxx> > Hi, If you are only interested in seeing what functions are called (and don't care about the order), why not just make another function profiler (see register_ftrace_profiler and friends)? Then you could just list the hash table entries instead of having to record into the ftrace ring buffer. -- Steve
