Re: Oprofile : need to adjust PC by 16 bytes

[Andi Kleen <andi@firstfloor.org>]

On Sat, Nov 15, 2008 at 05:30:58PM +0100, Eric Dumazet wrote:
> Andi Kleen a écrit :
> >>>And no, blindly subtracting 16 from IP is not a fix.
> >>Who mentioned a fix ? I am only giving more fuel to Intel guys so they
> >>hopefully can give us a working oprofile.
> >
> >You would need to implement PEBS support to avoid that problem. But it's a 
> >big
> >task. perfmon2 implements it already.
> >
> 
> Thanks for the information.
> 
> Hum, so I grabbed perfmon2 git tree, installed various tools...
> 
> I am quite new to pfmon and tried :
> 
> # pfmon --system-wide
> sizeof=64 44
> <press ENTER to stop session>
> 
> Then started "tbench 8", and got a kernel panic after 6 seconds.
> 
> 
> I was using oprofile like this
> 
> opcontrol --vmlinux=/path/vmlinux --start
> // doing some benchmarking...
> opreport -l vmlinux | head -n 40
> 
> 
> What would be a working equivalent for perfmon2 based tools ?

Probably getting a perfmon tree that works. I guess Stephane
can help (cc'ed).  Or just deal with imprecise events for now.

-Andi
-- 
ak@linux.intel.com