Re: Instruction Tracing for Linux

[Andi Kleen <ak@suse.de>]

On Fri, Jul 08, 2005 at 03:49:47PM -0500, Adnan Khaleel wrote:
> Thanks for your suggestions. I have been working with Simics, SimNow and Bochs. I've had mixed luck with all of them. Although Simics should be the most promising, I've really had
> an uphill struggle with it especially when it comes to x86-64. I've been playing around with Bochs and most likely will end up using that but it has its drawbacks as well. 

I haven't tested any recent versions, but the original development
was near mostly done with Simics and it did work well for me.

iirc there was a recent bug that the optimized memcpy or memset
in the glibc didn't like a CPU returning 0 bytes of cache size and
Simics did that. You might have run into that. It should be
fixed now.

Bochs used to be quite buggy on the x86-64 department and didn't do
multi processor, but that also might have changed. It is significantly
slower than the others.

> 
> Even if I can't trace the kernel, is there anything available for just the user space stuff?

The AMD CodeAnalyst for Linux has a simulator that first collects 
a trace and then runs that in a CPU model.  I assume it does
first single stepping. It's unfortunately binary only.

If slow single stepping is enough it's reasonably easy to write
something yourself too. I have old example source that implements
single stepping.

However I doubt any of them are capable of running the bigger
benchmarks.

-Andi