Shortly before I started this blog, Dave Wilder, a co-worker of mine, submitted a patch to LKML to implement a trace layer. Ever since the Linux Trace Toolkit, which was an attempt to introduce static tracepoints into the Linux kernel, tracing in the Linux kernel has been spotty at best. Back in “those days,” LTT received a substantial amount of opposition, possibly because of the resistance towards accepting features with the “enterprise” stigma. This stigma wasn’t entirely unfounded, given that enterprise features were frequently at odds with the needs of the bulk of the user base.
The introduction of kprobes has certainly provided a substantial boon for those interested in inserting tracepoints, and it’s nice seeing new technologies like this new trace layer being built on top of such a well-entrenched, though difficult to use, technology (this new patch was at least somewhat inspired by SystemTap). Given that there seems to be recognition that the barrier to accepting instrumentation should be lowered, perhaps it is time for reasonably generic trace technology to be implemented, and, more importantly, maintained.