Embedded Linux Development Using Yocto Project Cookbook - Second Edition

How it works...

A tracepoint is inserted using the TRACE_EVENT macro. It inserts a callback in the kernel source that gets called with the tracepoint parameters as arguments. Tracepoints added with the TRACE_EVENT macro allow ftrace or any other tracer to use them. The callback inserts the trace at the calling tracer's ring buffer.

To insert a new tracepoint into the Linux kernel, define a new header file with a special format. By default, tracepoint kernel files are located in include/trace/events, but the kernel has functionality so that the header files can be located in a different path. This is useful when defining a tracepoint in a kernel module.

To use the tracepoint, the header file must be included in any file that inserts the tracepoint, ...