Re: [2.4.17/18pre] VM and swap - it's really unusable

Bill Davidsen
2002-01-29T23:38:56Z

On Mon, 21 Jan 2002 yodaiken@fsmlabs.com wrote:

> I have not seen that argued - certainly I have not argued it myself.
> My argument is:
> It makes the kernel _much_ more complex
It modifies a tiny fraction of a percent of the kernel, which is
currently simplistic rather than simple. Nearly everyone who looks at it
makes some improvement, be it preempt, low latency, etc.

> It has known costs e.g. by making the lockless
> per-processor caching more difficult if not impossible
How much slowdown did you measure when you tested the effect of that?

> It seems to lead to a requirement for inheritance
To the limited extent that I agree, so what?

> It has no demonstrated benefits.
You have that backward. There are many people who say they can see a
benefit, and no one has shown either a quantified bad impact or a single
user account which said it was worse. And I bet you looked, didn't you?

I believe that a system will run better for a single user, and better
for a server with high interrupt rates, like DNS or web servers, where
many threads may be blocked on i/o, but there is significant CPU load as
well.

--
bill davidsen <davidsen@tmr.com>
CTO, TMR Associates, Inc
Doing interesting things with little computers since 1979.