On 14-Sep-06, at 6:23 PM, David Masover wrote:
Quinn Harris wrote:
On Thursday 14 September 2006 13:55, David Masover wrote:
...
That is a good point. Recording the disk layout before and after
to compare relative fragmentation would be a good idea. As well
as randomizing the sequence as a sanity check.
Also note that during boot I was using readahead on all 3885
files. So the kernel has a good opportunity to rearrange the
reads. And the read sequence doesn't necessary match the order
its needed (though I tried to get that).
Speaking of which, did you parallize the boot process at all?
Just off the top of my head, wouldn't that make the access sequence
asynchronous & thereby less predictable? (Although I'm sure it's a
net win.)
I'd estimate my system easily spent more than 50% of its boot time
not touching the disk at all before I did that. Gentoo can do
this, I'm not sure what else, as it kind of needs your init system
to understand dependencies.
...
