On Thu, 2006-02-16 at 18:12 +0100, Yann Rouillard wrote: > > I can't say I'm a fan of adding another flavour. How many people are > > actually using >4GB of memory on x86? I suspect (or hope) that people > > who are going to be doing those sorts of things will be using x86_64 > > and ia64 hardware. Christian's problem, aiui, is simply that the kernel > > sees 3.5GB instead of 4GB. I'm not sure whether this is by design, or is > > a bug, but I'd much rather see that fixed instead. > > This is not really a bug, see: > http://lists.us.dell.com/fom-serve/cache/68.html > http://lists.us.dell.com/pipermail/linux-poweredge/2004-November/017335.html > http://lists.us.dell.com/pipermail/linux-poweredge/2004-November/017342.html > > The 3.5GB-4GB address space is reserved for PCI devices, so, as only 4GB > can be adressed on 32bits proc, there is an address space shortage which > prevents using the 3.5GB-4GB RAM. > > So the only solution is to enable CONFIG_HIGHMEM64G to increase the > address space so that the 3.5GB-4GB RAM become addresseable. > > However I would be interested in some numbers/benchmarks on the > performance penalty of the PAE mode. Is this worth 512MB of additionnal > RAM ?
There was certainly a performance penalty last I checked (~1 year ago), but I don't have the numbers handy to back that up. I'd personally be happy with an additional pae flavor, but not changing the default. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
