Re: Autotune swappiness01

[R. J. Wysocki]

On Monday 26 of July 2004 20:45, Adam Kropelin wrote:
> On Mon, Jul 26, 2004 at 03:53:09PM +0200, R. J. Wysocki wrote:
> > On Monday 26 of July 2004 13:47, Nick Piggin wrote:
> > > Con Kolivas wrote:
> > > > Nick Piggin wrote:
> > > >> Con Kolivas wrote:
> > > >>> In my ideal, nonsensical, impossible to obtain world we have an
> > > >>> autoregulating operating system that doesn't need any knobs.
> > > >>
> > > >> Some thinks are fundamental tradeoffs that can't be autotuned.
> > > >>
> > > >> Latency vs throughput comes up in a lot of places, eg. timeslices.
> > > >>
> > > >> Maximum throughput via effective use of swap, versus swapping as
> > > >> a last resort may be another.
> > > >
> > > > As I said... it was ideal, nonsensical, and impossible. Doesn't sound
> > > > like you're arguing with me.
> > >
> > > No, you're right. My ideal operating system knows what the user
> > > wants too ;)
> >
> > Well, what I hate about various computer programs is that they seem to
> > assume to know what I (the USER) want and they don't let me do anything
> > else that they "know" what I should/would do. ;-)
> >
> > > Most of the time though, you are right. The quality/desirability of an
> > > implementation will be inversely proportional to the number of knobs
> > > sticking out of it (with bonus points for those that are meaningful to
> > > 2 people on the planet).
> >
> > Can you please tell me why you think that the least tunable
> > implementation should be the best/most desirable one?  I always prefer
> > the most tunable implementations which is quite opposite to what you have
> > said, but this is my personal opinion, of course.
>
> The implementation with the least *need* for tuning is the most
> desirable. I, for one, don't care if there are a dozen knobs as long as
> 99% of users don't have to touch them. But if common usage scenarios
> require turning knobs to get reasonable performance, the algorithm is
> lacking.

I agree in 100%.

> Thanks to fuel injection and engine management I can drive from LA to
> Denver and not need to tweak my carburator half way up the Rockies.
> I've given up some chances for tuning, but overall I'm better off. If
> you want to stick a trimpot or ten out the side of the engine management
> computer so true gearheads can tweak another couple HP or MPG out of the
> engine, great. But don't expect me to fiddle with it every time driving
> conditions change; it's not an excuse to make the management algorithms
> inadequate for common driving patterns.

I didn't mean that.  Actually, I was trying to say that an additional "knob" 
(or "knobs") might be useful in determining the "common settings" acceptable 
for the 99% of users.  Then, it could be "hidden" (which I wouldn't do, but 
well ...).

Yours,
rjw

-- 
Rafael J. Wysocki
[tel. (+48) 605 053 693]
----------------------------
For a successful technology, reality must take precedence over public 
relations, for nature cannot be fooled.
					-- Richard P. Feynman
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/