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RE: Attempting to try out "asynchronous probes" and the current runtime...
- From: "Spirakis, Charles" <charles dot spirakis at intel dot com>
- To: "William Cohen" <wcohen at redhat dot com>
- Cc: <systemtap at sources dot redhat dot com>
- Date: Mon, 11 Jul 2005 10:02:05 -0700
- Subject: RE: Attempting to try out "asynchronous probes" and the current runtime...
Thanks, I'll take a look.
I was planning on looking at oprofile's timing mechanism in general to
see about using a hardware timer instead which would also work for smp
machines. Was hoping to try this as the "easier" test case first, but it
may not have been as easy as I thought :)
-- charles
> -----Original Message-----
> From: systemtap-owner@sources.redhat.com
> [mailto:systemtap-owner@sources.redhat.com] On Behalf Of William Cohen
> Sent: Monday, July 11, 2005 8:28 AM
> To: Spirakis, Charles
> Cc: systemtap@sources.redhat.com
> Subject: Re: Attempting to try out "asynchronous probes" and
> the current runtime...
>
> Spirakis, Charles wrote:
> > All --
> >
> > I'm playing around with an "asynchronous probe" concept and the
> > current runtime using simple os timers (code is below). Anyone have
> > experience with task_pt_regs() function? As you can see,
> I'm trying to
> > grab the "current" pt_regs in the home of seeing the eip at
> the time
> > of the timer interrupt, but the data I get is not what I'd hoped.
> >
> > This is running on a Pentium M laptop with the mm2 kernel,
> > CONFIG_PREEMPT_NONE=y, other preemption configs are not set.
> >
> > -- charles
>
> You might take a look at the fall back timer interrupt
> mechanism in OProfile to see how it works. In particular look
> at the linux/driver/oprofile/timer_int.c.
>
> I noticed there are a couple things that were i386 specific
> in the example, use of regs->eip and task_pt_regs.
>
>
> -Will
>