Re: [PATCH v3 00/14] perf, x86: Haswell LBR call stack support

[David Ahern]

On 2/26/14, 12:25 PM, Andy Lutomirski wrote:
> On Wed, Feb 26, 2014 at 11:19 AM, David Ahern <dsahern@xxxxxxxxx> wrote:
> > On 2/26/14, 11:59 AM, Andy Lutomirski wrote:
> >
> > > I wonder if anyone who uses perf for userspace profiling *ever* uses
> > > FP and gets away with it.  There's precious little userspace software
> > > compiled with frame pointers these days on most architectures.
> >
> >
> > yes and yes. With control over the entire stack we are making sure
> > frame-pointers are enabled as much as possible.
>
> I'm curious why.

Is there some reason not to enable frame pointers?

fp method has much less overhead than dwarf, and good, clear callchains 
are important.

> Maybe this should be a config option.  Anyone using a standard distro
> is running a nearly completely frame-pointer-omitted userspace these
> days.

Does WRL or Yocto fall into that 'standard distro' comment? Fairly easy 
to enable frame-pointers.

David
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