Messages in this thread | | | Date | Tue, 16 Sep 2003 18:16:58 -0300 (BRT) | From | Marcelo Tosatti <> | Subject | Re: experiences beyond 4 GB RAM with 2.4.22 |
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On Tue, 16 Sep 2003, Olivier Galibert wrote:
> 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.
Which card and driver are you using for IO? 3ware?
How much RAM do you have?
I remember I tested heavy IO loads (heavy swapping and dbench) on 8GB machine and all worked fine (interactive terminal, etc) but that was a looong time ago back in 2.4.
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