Re: Tapset for probing IRQs, workqueues, etc

[Prerna Saxena <prerna at linux dot vnet dot ibm dot com>]

Hi ,
Posting a new version of the IRQ tapset.

On 10/27/2009 01:42 AM, David Smith wrote:

> 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.

I have not included the flags string on purpose for this probe point, 
cos I think that one might need to look up the flags in specific 
debugging scenarios only. It would not be required in most commonly used 
cases, such as the attached example. However, I have documented the 
function both inline in the tapset documentation and also in the man 
pages, so that a script developer wanting to display a formatted string 
can call the function when needed.

> 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.

Thanks for the suggestion, I've tried to make the tapset follow the 
guidelines specified above.

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

The present version includes :
1. IRQ tapset
2. testcase for checking if probes resolve & build fine.
3. Example script for profiling interrupts per device in a given time 
interval.
4. man pages for the tapset.
5. Updates to tapsets.tmpl so that documentation is auto-generated for 
the tapset.

Josh,
   Thanks for pointing me to the redundancy of using @cast. I've 
replaced it with direct resolution.

Hope I've covered things needed.. Looking fwd to suggestions !

--
Prerna Saxena

Linux Technology Centre,
IBM Systems and Technology Lab,
Bangalore, India

Attachment: irq-patch
Description: Text document