Re: [RFC] ftrace: support tracing functions in one module

[fche@redhat.com (Frank Ch. Eigler)]

"Ming Lei" <tom.leiming@gmail.com> writes:

> [...]  For example, one may only have interest in functions calling
> in usbcore.ko, but he must trace all the functions calling in the
> kernel, so the tracing result is too large to use it. [...]

Until ftrace gains this ability, you could use systemtap:

# cat callret.stp
probe $1.call { printf ("%s <- %s\n", thread_indent(1), probefunc()) }
probe $1.return { printf ("%s -> %s\n", thread_indent(-1), probefunc()) }
# stap callret.stp 'module("usbcore").function("*")'
[...]
^C
#

(One can also add conditions based on function parameters, processes,
whatever; soon it'll be easy to trace all function parameters.)


- FChE