Date: Thu, 8 Jul 1999 11:04:47 +0930 From: Greg Lehey <grog@lemis.com> To: Peter Jeremy <jeremyp@gsmx07.alcatel.com.au> Cc: freebsd-current@FreeBSD.ORG, freebsd-hackers@FreeBSD.ORG Subject: Bursting at the seams (was: Heh heh, humorous lockup) Message-ID: <19990708110446.P2340@freebie.lemis.com> In-Reply-To: <99Jul8.090830est.40363@border.alcanet.com.au>; from Peter Jeremy on Thu, Jul 08, 1999 at 09:26:09AM %2B1000 References: <99Jul8.090830est.40363@border.alcanet.com.au>
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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 <dillon@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 grog@lemis.com for PGP public key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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