Many mfgpt timer interrupts with tickless kernel

[Jens Axboe]

On Thu, Mar 22 2007, William Cohen wrote:
> Chris Ball wrote:
> >Hi Will,
> >
> >   > I need to put a probe at a higher level to see what is run when the
> >   > timer fires. Is there something that can print out what is in the
> >   > clockevents_chain?
> >
> >Not sure if you're aware that there are timer statistics available:
> 
> 
> Chris,
> 
> Thanks for the additional details on how to use the timer statistics. Here 
> are a few more details one what is going on. Definitely there are 
> additional timers being set up for systemtap. Below is what is running when 
> the systemtap instrumentation is running on the system. -Will

Remember Heisenberg, systemtap is definitely invasive if you are trying
to profile timer usage. So if that is what you are hunting, get rid of
systemtap and just look at the timer stats isolated.


-- 
Jens Axboe