2002-07-13 18:55:35

by Randy Hron

[permalink] [raw]
Subject: oprofile results with lmbench

oprofile gives access to cpu performance counters on x86.

I ran oprofile with the individual lmbench tests to get
data from several of the counters. This "hot kernel
function" and counter info may be useful. A web page with the
results from 5 of the performance counters for each
lmbench test is at:

http://home.earthlink.net/~rwhron/kernel/lmbench_oprofile.html

I'll add the rest of the counter data over the next few days.
Comments/caveats on how to make the information more useful are
welcome.

The target kernel was 2.4.19rc1aa1 on an Athlon 1333.

--
Randy Hron
http://home.earthlink.net/~rwhron/kernel/bigbox.html


2002-07-13 20:34:37

by Randy Hron

[permalink] [raw]
Subject: Re: oprofile results with lmbench

> the numbers don't look right.

> Perhaps you fed oprofpp the wrong vmlinux?

Thanks! You are right. I just put a bold message
on the page that the results are invalid. I'm leaving
the page up in case anyone else recommends changes.
I'll re-run the tests.

> btw, when using RETIRED_INSNS (or CPU_CLK_UNHALTED), you should
> boot the kernel with `idle=poll'. Otherwise, idle time is
> unaccounted for in the profile and it gets really hard to interpret,
> and hard to compare runs.

I've added "idle=poll" to my lilo.conf append.

--
Rands Hron
http://home.earthlink.net/~rwhron/kernel/bigbox.html