On Thursday, 8 July 1999 at 9:26:09 +1000, Peter Jeremy wrote: > David Greenman wrote: >> Yes, I do - at least with the 512MB figure. That would be half of the 1GB >> KVA space and large systems really need that space for things like network >> buffers and other map regions. > > Matthew Dillon <dil...@apollo.backplane.com> wrote: >> What would be an acceptable upper limit? 256MB? 128MB? The test >> I ran (Kirk's news test) ate around 60MB for the "FFS Node" memory area >> before the number of vnodes stabilized, on a 1GB machine. I would say >> that a 128MB upper limit would be too small for a 4G machine. A 256MB >> limit ought to work for a 4G machine > > It appears we're rapidly approaching the point where 32-bits isn't > enough. We could increase KVA - but that cuts into process VM space > (and a large machine is likely to have large processes). > > The other option is moving away from a flat memory model: How about > putting some of the larger kernel-only data-structures into another > segment? The downside is that unless we want to start passing `far' > pointers around (which is both ugly and inefficient), we need to > make the pointer address space transparent to the compiler.
Why not put the kernel in a different address space? IIRC there's no absolute requirement for the kernel and userland to be in the same address space, and that way we would have 4 GB for each. Greg -- See complete headers for address, home page and phone numbers finger g...@lemis.com for PGP public key To Unsubscribe: send mail to majord...@freebsd.org with "unsubscribe freebsd-hackers" in the body of the message
