Re: [PATCH v2 3/7] Adding general performance benchmarking subcommand to perf.

From: Ingo Molnar <mingo@elte.hu>
To: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: linux-kernel@vger.kernel.org,
	"Rusty Russell" <rusty@rustcorp.com.au>,
	"Thomas Gleixner" <tglx@linutronix.de>,
	"Peter Zijlstra" <a.p.zijlstra@chello.nl>,
	"Mike Galbraith" <efault@gmx.de>,
	"Arnaldo Carvalho de Melo" <acme@redhat.com>,
	Frédéric_Weisbecker <fweisbec@gmail.com>
Subject: Re: [PATCH v2 3/7] Adding general performance benchmarking subcommand to perf.
Date: Tue, 3 Nov 2009 18:29:26 +0100	[thread overview]
Message-ID: <20091103172926.GC11535@elte.hu> (raw)
In-Reply-To: <20091103.195535.789626513029853730.mitake@dcl.info.waseda.ac.jp>

* Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp> wrote:

> 
> Adding general performance benchmarking subcommand to perf.
> This patch adds bench/sched-pipe.c.
> 
> bench/sched-pipe.c is a benchmark program
> to measure performance of pipe() system call.
> This benchmark is based on pipe-test-1m.c by Ingo Molnar.
> http://people.redhat.com/mingo/cfs-scheduler/tools/pipe-test-1m.c
> 
> Example of use:
> % perf bench sched pipe               # Use default options
> 4.575  	     	   		      # Result is time
> % perf bench sched pipe -l 2000	      # This option means "loop 2000 counts"
> 0.024

ok, -l makes sense.

Shouldnt we output the unit of measurement, i.e. '4.575 usecs'? Also, we 
should perhaps print something like:

  % perf bench sched pipe

  (executing 1000000 pipe operations between two tasks)

     4.575 usecs per op
    218579 ops/sec   

?

	Ingo