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

Chris Friesen
2002-01-21T22:47:16Z

Horst von Brand wrote:
>
> Robert Love <rml@tech9.net> said:
>
> [...]
>
> > It doesn't have to run mostly in the kernel. It just has to be in the
> > kernel when the I/O-bound tasks awakes. Further, there are plenty of
> > what we consider CPU-bound tasks that are interactive and/or
> > graphics-oriented and this adds much to their time in the kernel.
>
> Look, I don't know about you, but system (kernel) tieme around here is
> rarely very high as a %. Perhaps 5% could be called "typical". And it is
> during those 5% (i.e., something like 5% of the time) any of this stuff
> will make a difference at all. This will be _hard_ to "feel" (if it is
> possible to feel at all).

As a thought experiment...

1) top usually averages over 5 seconds
2) 5% of 5 seconds is 0.25 seconds

What I'm getting at is that it is possible that there are cases where we could
be taking significant amounts of time to respond to something, without the
overall average being too high.

If we have even a single 0.1 second delay, that's going to be noticeable to the
user without seriously bumping up system percentages.

--
Chris Friesen | MailStop: 043/33/F10
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