dtrace discuss - Aug 2006 - pid provider and overheads

Hi:

I am using pid provider for a process function tracing. I observed more than 10%
CPU
drop.  May I know the pointer for the user land function tracing of pid provider
with lower overhead ?


Thanks
 
 
This message posted from opensolaris.org

Are you saying that running DTrace used 10% of your CPU?  May we see 
your DTrace script?

Thanks,
Chip

ttoulliu2002 wrote:
> Hi:
>
> I am using pid provider for a process function tracing. I observed more
than 10% CPU
> drop.  May I know the pointer for the user land function tracing of pid
provider with lower overhead ?
>
>
> Thanks
>  
>  
> This message posted from opensolaris.org
> _______________________________________________
> dtrace-discuss mailing list
> dtrace-discuss at opensolaris.org
>

I''m not sure I completely understand your question, but I gather that
you''re
unhappy with the performance of the pid provider and are looking for a better
solution. The overhead from the pid provider can be substantial (especially
if you''re tracing every instruction); some efforts have been made to
optimize
common paths (the entry and return probes for example) so you can help
yourself out by using those probes. It is impossible to drive the overhead
to zero -- we''re doing additional work to perform the requested tracing
-- and
your best bet is to try to minimize the number of probes you''re using.

If you send your script, we may be able to have more concrete suggestions.

Adam

On Fri, Aug 18, 2006 at 10:34:54AM -0700, ttoulliu2002
wrote:
> Hi:
> 
> I am using pid provider for a process function tracing. I observed more
than 10% CPU
> drop.  May I know the pointer for the user land function tracing of pid
provider with lower overhead ?
> 
> 
> Thanks
>  
>  
> This message posted from opensolaris.org
> _______________________________________________
> dtrace-discuss mailing list
> dtrace-discuss at opensolaris.org
-- 
Adam Leventhal, Solaris Kernel Development       http://blogs.sun.com/ahl