Subject: Re: user profiling improvements
To: Eduardo Horvath <eeh@turbolinux.com>
From: Jason R Thorpe <thorpej@zembu.com>
List: tech-kern
Date: 08/11/2000 10:40:45
On Fri, Aug 11, 2000 at 09:35:23AM -0700, Eduardo Horvath wrote:

 > > It's not like you're counting it "against the process".  But profiling
 > > is supposed to tell you where a process is spending its time, and if your
 > > process is I/O bound, you want to know exactly how much time is spend in
 > > those I/O routines.  We currently don't have that.
 > 
 > Then you probably want to separate iowait time from just sleeping.

So, what's i/o wait time?  File system I/O?  Network I/O?  What about
I/O as a result of a page fault?  What about some other kind of
long-to-complete system call?

I think counting this time is perfectly legit, you want to know how
you got to that sleep and how long it took.

-- 
        -- Jason R. Thorpe <thorpej@zembu.com>