Subject: Re: [2.4.17/18pre] VM and swap - it's really unusable
To: zippel@linux-m68k.org (Roman Zippel)
Date: Sun, 13 Jan 2002 15:45:06 +0000 (GMT)
Cc: alan@lxorguk.ukuu.org.uk (Alan Cox), rml@tech9.net (Robert Love),
        ken@canit.se (Kenneth Johansson), arjan@fenrus.demon.nl,
        landley@trommello.org (Rob Landley), linux-kernel@vger.kernel.org
In-Reply-To: <3C41A545.A903F24C@linux-m68k.org> from "Roman Zippel" at Jan 13, 2002 04:18:29 PM
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From: Alan Cox <alan@lxorguk.ukuu.org.uk>
Sender: linux-kernel-owner@vger.kernel.org

> What somehow got lost in this discussion, that both patches don't
> necessarily conflict with each other, they both attack the same problem
> with different approaches, which complement each other. I prefer to get
> the best of both patches.

When you look at the benchmark there is no difference between ll and 
ll+pre-empt. ll alone takes you to the 1ms point. pre-empt takes you no
further and to get much out of pre-emption requires you go and do all the
hideously slow and complex priority inversion stuff.

> exactly that reason. I don't think we need to work around broken
> hardware, but halfway decent hardware should not be a problem to get
> decent latency.

We have to work around common hardware not designed for SMP - the 8390 isnt
a broken chip in that sense, its just from a different era, and there are a 
lot of them.

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