hyper threading.

[em1897 at aol.com]

Polling is simply unecessary in most cases. You could get
better performance using an em driver and setting max
ints to whatever is optimal for your system. Polling adds
latency and over head for no good reason.

As I've said before, the FreeBSD "team" is patently
clueless. They're grasping at straws.

-----Original Message-----
From: Anthony Atkielski <atkielski.anthony at wanadoo.fr>
To: freebsd-questions at freebsd.org
Sent: Sun, 27 Mar 2005 20:04:16 +0200
Subject: Re: hyper threading.

em1897 at aol.com writes:

> Right. Thats what I said. You'll killl your networking.

Beyond a certain network load, you have to increase the number of timer
interrupts per second no matter how fast your processors are or how many
of them you have, if you are polling your I/O interfaces instead of
being driven from interrupts.

I don't like the idea of routinely running 1000 timer interrupts per
second, but I note that FreeBSD 6.x apparently is moving to this number
(?).  I'd prefer that it be readily configurable.

There are other options but I'm not sure how well x86 hardware supports
them.  Having a very accurate, very high resolution elapsed-time counter
on the processor(s) can help lower overhead by allowing the OS to get
accurate time information without waiting for an interrupt and with
execution of only a single instruction.  Having programmable, very high
resolution timers would help, too.

--
Anthony


_______________________________________________
freebsd-questions at freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-questions
To unsubscribe, send any mail to 
"freebsd-questions-unsubscribe at freebsd.org"