dtrace discuss - Nov 2005 - Where & Why is my process sleeping a lot?

I have a program where the process seems to be sleeping a lot (waiting 
on something)

What would be the right approach to figure out  via dtrace where it is 
sleeping and why it is sleeping?

In my current process, using truss -D shows that  it reaches pollsys and 
the whole process sleeps for 1.5 - 1.8 seconds before it awakes again. 
Its the only significant process running on this two CPU (socket) V20z.

I am trying to figure out how can I use Dtrace to answer the question 
"Where and why is the process sleeping?"

Any sample scripts will help.

Thanks.

Regards,
Jignesh

Hi Jignesh,

You might want to take a look at the chapter on the sched provider:

  http://docs.sun.com/app/docs/doc/817-6223/6mlkidll6?a=view

Specifically, the off-cpu and sleep probes might help you figuring out
where your threads are sleeping.

Adam

On Wed, Nov 09, 2005 at 03:56:02PM -0500, Jignesh K. Shah
wrote:
> I have a program where the process seems to be sleeping a lot (waiting 
> on something)
> 
> What would be the right approach to figure out  via dtrace where it is 
> sleeping and why it is sleeping?
> 
> In my current process, using truss -D shows that  it reaches pollsys and 
> the whole process sleeps for 1.5 - 1.8 seconds before it awakes again. 
> Its the only significant process running on this two CPU (socket) V20z.
> 
> I am trying to figure out how can I use Dtrace to answer the question 
> "Where and why is the process sleeping?"
> 
> Any sample scripts will help.
> 
> Thanks.
> 
> Regards,
> Jignesh
> 
> _______________________________________________
> dtrace-discuss mailing list
> dtrace-discuss at opensolaris.org
-- 
Adam Leventhal, Solaris Kernel Development       http://blogs.sun.com/ahl