Re: [PATCH v2 00/11] KVM in-guest performance monitoring

[Peter Zijlstra <a.p.zijlstra@chello.nl>]

On Thu, 2011-06-16 at 09:19 -0600, David Ahern wrote:
> 
> On 06/16/2011 09:08 AM, Peter Zijlstra wrote:
> > On Thu, 2011-06-16 at 08:08 -0600, David Ahern wrote:
> >> Command:
> >>   perf stat -e instructions  openssl speed aes
> >>
> >> Guest:
> >>    135,522,189,056 instructions              #    0.00  insns per cycle
> >>
> >>
> >> Host:
> >>    346,082,922,185 instructions              #    0.00  insns per cycle 
> > 
> > How does: perf stat -e instructions:u openssl speed aes, compare?
> 
> In the past couple of months I recall you posted a one billion
> instruction benchmark in analyzing perf correctness. I can't seem to
> find that email. Do you recall the benchmark and if so can you resend ?

Sure, I've got a couple of those things lying around:

# perf stat -e instructions:u ./loop_1b_instructions-4x

 Performance counter stats for './loop_1b_instructions-4x':

     4,000,085,344 instructions:u            #    0.00  insns per cycle        

       0.311861278 seconds time elapsed

---

#include <stdlib.h>
#include <stdio.h>
#include <time.h>

main ()
{
	int i;

	fork();
	fork();

	for (i = 0; i < 100000000; i++) {
		asm("nop");
		asm("nop");
		asm("nop");
		asm("nop");
		asm("nop");
		asm("nop");
		asm("nop");
	}
	wait(NULL);
	wait(NULL);
	wait(NULL);
	wait(NULL);
}