On Mon, 13 May 2002, Rik van Riel wrote:

Hi,

the following patch implements iowait statistics in a simple way:

This follows some work I was doing back in 2.4.10 or so WRT just measuring
the delay caused by waiting for page IO. Attached is a patch against
2.4.19-pre8-ac3 which is the offspring of preempt-kernel and Rik's waitio
patch. All I can claim is that it still runs and boots, seems to have
working preempt, and returns reasonable numbers for iowait on a uni
processor. I intend to test more, but I know that this is a popular ac
version, and hopefully this will be useful.

  Until I try this on a real machine and see what tuning of things like
hdparm and elvtune do, test rmap again -aa, etc, this is an exercise in
getting it to work. I'd be interested in feedback, and I hope Rik will
continue his development.

-- 
bill davidsen [off-list ref]
  CTO, TMR Associates, Inc
Doing interesting things with little computers since 1979.