From: Robert Klemme <shortcutter@...>
Date: 2010-02-21T22:30:04+09:00
Subject: Re: Read efficiency?

On 02/21/2010 09:08 AM, Notmy Realname wrote:
> I hate it when I put my foot in my mouth. After further testing, I'm 
> almost entirely sure this is just due to overhead, not a problem with 
> disk access.

Good that you did not use your real name. ;-)

> Who would have thought looping 11*2**20 times would incur a performance 
> hit?

The overhead of a simple method call is significant already:

robert@fussel:~$ ruby19 -r benchmark <<XXX
def f;end # function without effect
R1=11*1024*1024
R2=R1/4096
Benchmark.bmbm 20 do |r|
r.report("rare") { R2.times { f } }
r.report("often") { R1.times { f } }
end
XXX

Rehearsal -------------------------------------------------------
rare                  0.000000   0.000000   0.000000 (  0.000643)
often                 2.620000   0.000000   2.620000 (  2.663366)
---------------------------------------------- total: 2.620000sec

                           user     system      total        real
rare                  0.000000   0.000000   0.000000 (  0.000643)
often                 2.620000   0.000000   2.620000 (  2.665057)
robert@fussel:~$

Kind regards

	robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/