On Jan 31, 2009, at 7:27 PM, Robert Watson wrote:
There are basically three ways to go about exploring this, none
particularly good:
(1) Do a more formal before and after analysis of performance on the
box,
perhaps using tools like kernel profiling, hwpmc, dtrace, etc.
Machine in production, I cannot do it :(
(2) Do a binary search to narrow down the date of the change that
improved
things until it becomes clear which mattered.
(3) Hope someone annecdotally remembers something that might or
might not be
it and assume they're right.
Of these, I'd guess (2) is actually the most effective way to go
about it, but is potentially time-consuming. As you point out, the
most interesting question is whether, when you go back to 7.0,
things suddenly get slower again, or not. Typically long uptimes
don't lead to performance problems on FreeBSD (in my experience) so
I think that's unlikely to be the source. There are a lot of
improvements in 7.1 relating to performance, but none particularly
stands out for me as having the effect you describe. If you're
really curious, I would try to pin it down with a binary search.
I will have to learn how to use dtrace, I think. This is quite weird.
And in a lot of years I haven't seen a FreeBSD system degraded because
of a long uptime. Something in userland must be the culprit...
As I see (I don't administer the machine but co-administer it) there's
a Qmail system with some AV crap... and now I see that active memory
had gone up, and is much lower after the update.
I'll keep investigating.. the kind of answer I was looking for was a
"oh, yes, there was a problem that degraded, blah, blah, blah".
The graphs can be accessed here: http://194.30.110.21/orca/
It's behind an ADSL, so expect slow performance.
Borja.
_______________________________________________
freebsd-stable@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-stable
To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
