Re: Tapset for probing IRQs, workqueues, etc

[David Smith <dsmith at redhat dot com>]

On 10/23/2009 12:36 PM, Prerna Saxena wrote:
> Hi,
> 
> Attached is a tracepoint based tapset for probing IRQ handlers,
> softirqs, and workqueue operations.
> Of these, softirqs and irq handler based probes cannot have kprobe
> equivalents, 'cos of the kprobe blacklist. And the position of
> tracepoints for workqueues makes it difficult to define a kprobe
> fallback for most of these probes.
> 
> Looking fwd to feedback to improve it..

I took a short look at your tapset.  In general, it looks fine.

I do have one question.  You added a function called '_irqflags_str' to
aux_syscalls.stp, but I couldn't find a caller of that new function in
your tapset.  It looks like you might have meant to call it for the
'flags' variables in irq_handler.entry and irq_handler.exit.

It would be really nice if your new tapset automatically generated its
own documentation.  I don't think it would be much additional work over
the comments you have now.  See the "Documentation" section of the
"Tapset Developer's Guide"
<http://sources.redhat.com/git/?p=systemtap.git;a=blob_plain;f=tapset/DEVGUIDE>
for more details.

It would also be great if your tapset had a simple testcase that made
sure everything compiled.

-- 
David Smith
dsmith@redhat.com
Red Hat
http://www.redhat.com
256.217.0141 (direct)
256.837.0057 (fax)