Re: iostat-scsi.stp

Re: iostat-scsi.stp

[Frank Ch. Eigler]

Hi -

On Fri, Dec 19, 2008 at 05:51:13PM +0100, Krahbichler Roland wrote:
> [...]
> # stap -g iostat-scsi.stp 10
> WARNING: cannot find module sd_mod debuginfo: Unsupported relocation type
> semantic error: no match while resolving probe point module("sd_mod").function("sd_init_command")
> [...]
> but the module is already loaded:
> filename:       /lib/modules/2.6.25.5-1.1-default/kernel/drivers/scsi/sd_mod.ko
> [...]

A web search of "systemtap unsupported relocation" indicates two
possible causes, one of which was an installation glitch with
elfutils.  Please give more information about how systemtap was built;
"stap -V"; or if your installation is recent enough, the relevant bits
of the "stap-report" output.

- FChE

Re: iostat-scsi.stp

[Frank Ch. Eigler]

Hi -

> version:
> SystemTap translator/driver (version 0.6.1/0.137 built 2008-06-06)
> [...]

Yeah, pretty old, but that should not account for the present problems.

> i didn´t know anything about glitch but i installed libelf1 on the system.
> # rpm -ql libelf1-0.137-4.18
> /usr/lib64/libelf-0.137.so
> /usr/lib64/libelf.so.1

Please check whether /usr/lib*/elfutils/libebl* are also installed.
You could also run stap under strace to see whether it's finding
these various elfutils shared libraries: something like
% strace -eopen stap ...

> stap-report isn´t a part of systemtap in the version 0.6 wich i
> have. should i upgrade to a newer version

That's not necessary for the current problem, but there are other
reasons one may wish to upgrade.

> and did i need the systemtap-debuginfo?

One needs the -debuginfo for a package mainly if one needs to debug
that package.  That does not seem to be an issue here yet.

- FChE