script(s) for tracking execution paths

[William Cohen]

Tom Zanussi wrote:
> Hi,
> 
> I've been having some fun playing around with maps keyed on stack
> traces (very cool to be able to do this) and have checked into
> systemtap.samples a systemtap script (kmalloc-stacks.stp) and a perl
> script (kmalloc-top) that in combination continuously track the
> different execution paths to kmalloc().  It keeps counts of the
> different execution paths in a systemtap hash, and periodically dumps
> the hash contents (and clears the hash table) to the perl script,
> which rehashes them in user space.  At the end of the run (Ctrl-C), it
> sorts the accumulated hash table and filters out any stacks that
> contain any of the user-supplied regexps (-e option), which helps cut
> down on noise e.g.
> 
> # ./kmalloc-top -e sys_select,alloc_skb
> 
> Here's an example of the output (gathered over a kernel compile):

Hi Tom, I have been playing around with the kmalloc example you checked 
in. When running it, I have seen a couple panics like the one in the 
photo at:

http://people.redhat.com/wcohen/100_0405.jpg

This is on a pentium III machine running the rawhide with the current 
kernel:

Linux trek.devel.redhat.com 2.6.13-1.1555_FC5smp #1 SMP Wed Sep 14 
15:59:49 EDT 2005 i686 i686 i386 GNU/Linux


-Will