On Mon, Oct 08, 2007 at 03:08:17PM +0200, Karel Zak wrote:
On Fri, Oct 05, 2007 at 04:02:21PM -0400, Dave Jones wrote:
Right now we're running readahead early way too late. At a time when we've just sat doing no IO at all for 10 seconds whilst (amongst other things) we waited for a DHCP lease. We're also running it at a time when we're competing for disk bandwidth with other processes. The result is that disabling the service completely shows no change in boot time at all. http://www.codemonkey.org.uk/junk/bootchart-before.png
Moving the readahead_early service to start really early wins back 4 seconds of boot up time. http://www.codemonkey.org.uk/junk/bootchart-after.png
Please, define "really early".
I moved it to S01
results (readahead on/off):
http://people.redhat.com/kzak/readahead/f7-on.png http://people.redhat.com/kzak/readahead/f7-off.png
.. so nothing useful :-(
Any reason not to change this for F8 ?
I don't believe that readahead is able to really improve Fedora boot time.
So over the weekend I reinstalled that test box with test3, and made the same change to readahead. This time it didn't make any difference at all, so I'm inclined to believe you.
Eric Sandeen noted that it actually *slows down* his boot too, so perhaps switching it off is the best plan.
Dave