Re: experiences beyond 4 GB RAM with 2.4.22

[Olivier Galibert]

On Tue, Sep 16, 2003 at 07:10:57PM +0200, Pavel Machek wrote:
> Hi!
> 
> > > Well, I do understand the bounce buffer problem, but honestly the current way
> > > of handling the situation seems questionable at least. If you ever tried such a
> > > system you notice it is a lot worse than just dumping the additional ram above
> > > 4GB. You can really watch your network connections go bogus which is just
> > > unacceptable. Is there any thinkable way to ommit the bounce buffers and still
> > > do something useful with the beyond-4GB ram parts?
> > 
> > The 2.6 tree is somewhat better about this but at the end of the day if
> > your I/O subsystem can't do the job your box will not perform ideally.
> > For some workloads its a huge win to have the extra RAM, for others the
> > I/O is a real pain. 
> 
> If he has trouble logging in, then there's a bug somewhere.
> Bounce buffers should not slow machine down more than
> 2x, and from his description it looks like way worse slowdown. 

The box does not just slowdown, the box crawls on the floor wimpering.
Nothing works except ping until the i/os are finished (and they seem
to crawl too), then everything works perfectly again.

We're quite eager to fix the problem too, if you want us to test some
things.

  OG.

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