Differences of stack traces between linux kernel and systap

[Frank Ch. Eigler]

"Peter Teoh" <htmldeveloper@gmail.com> writes:

> Notice the diference in the stack trace between systap:
>[...]
> And that of the linux kernel (latest patch):
>  [<c042bad6>] warn_on_slowpath+0x46/0x56
>  [<c0415a33>] ? apic_wait_icr_idle+0x16/0x1d
>  [<c0415243>] ? __send_IPI_dest_field+0x50/0x54
>[...]
> The difference lies in the "?" in front of the function, which is to
> indicate that this function has just been executed and returned, so it
> is no longer on the stack.

I'm sorry, I don't know what that could possibly mean.  A function
that has executed and returned should leave no traces on the stack.
Can you identify the "latest patch" that purports to implement this?

> Is it possible to modify the systap stacktrace dump to be inlined
> with that of the kernel?  It this not more informative?

You mean integrated?  Perhaps.  In the mean time, a more pressing
thing to do is to get userspace backtraces working.

- FChE