newbie question : compiling kernel and debug info.

newbie question : compiling kernel and debug info.

[Om Narasimhan]

When I started using systemtap, I had tried to compile my kernel and use 
systemtap (binary -- came with fedora) on it. But I was not very 
successful (I used to get a number of symbol mismatch/function not found 
..etc errors) and finally I started using systemtap with Fedora kernel. 
So far, it has worked fine.

$ stap -V
SystemTap translator/driver (version 0.6.2/0.127 built 2008-03-27)
Copyright (C) 2005-2008 Red Hat, Inc. and others

$ uname -a
Linux mophia.sfbay.sun.com 2.6.23.17-88.fc7 #1 SMP Thu May 15 00:02:29 
EDT 2008 x86_64 x86_64 x86_64 GNU/Linux

Some questions on compiling custom kernels
1. Should I compile and replace my existing systemtap with a newer 
version in order to use it for a custom-compiled kernel? (Is there any 
relation between system tap binary and kernel on which it is used?)

2. How to compile modules with debuginfo?

Thanks,
Om.

Re: newbie question : compiling kernel and debug info.

[Frank Ch. Eigler]

Om Narasimhan <Om.Narasimhan@Sun.COM> writes:

> When I started using systemtap, I had tried to compile my kernel and
> use systemtap (binary -- came with fedora) on it. But I was not very
> successful (I used to get a number of symbol mismatch/function not
> found ..etc errors) and finally I started using systemtap with Fedora
> kernel. So far, it has worked fine.

Glad to hear.

> Some questions on compiling custom kernels
> 1. Should I compile and replace my existing systemtap with a newer
> version in order to use it for a custom-compiled kernel? (Is there any
> relation between system tap binary and kernel on which it is used?)

Any given systemtap binary should work fine with a range of kernels.
The runtime side (kernel module source code) is more kernel-sensitive,
but we have some mechanisms in place to make them work on a range
also.

> 2. How to compile modules with debuginfo?

If the main kernel has debugging information, the modules will too,
since they are compiled the same way.

- FChE