From owner-freebsd-hackers Mon Jan 8 14:46:19 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id OAA15046 for hackers-outgoing; Mon, 8 Jan 1996 14:46:19 -0800 (PST) Received: from phaeton.artisoft.com (phaeton.Artisoft.COM [198.17.250.211]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id OAA15040 for ; Mon, 8 Jan 1996 14:46:11 -0800 (PST) Received: (from terry@localhost) by phaeton.artisoft.com (8.6.11/8.6.9) id PAA10640; Mon, 8 Jan 1996 15:41:37 -0700 From: Terry Lambert Message-Id: <199601082241.PAA10640@phaeton.artisoft.com> Subject: Re: large files To: davidg@root.com Date: Mon, 8 Jan 1996 15:41:36 -0700 (MST) Cc: terry@lambert.org, gpalmer@westhill.cdrom.com, wosch@cs.tu-berlin.de, hackers@freebsd.org In-Reply-To: <199601082123.NAA01772@corbin.Root.COM> from "David Greenman" at Jan 8, 96 01:23:13 pm X-Mailer: ELM [version 2.4 PL24] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-hackers@freebsd.org Precedence: bulk > >I believe the restriction is based on mmap'ed files taking a portion > >of the kernel address space equal to their size. This is arguably > >a design flaw in the mmap implementation. > > > >Really, mmap wants to operate on a demand paged window and arrange > >the vnode as the mappable entity so that it can be shared between > >various processes without taking kernel address space to do it. > > This is absolutely, 100% wrong. It does NOT work like that. Actually, John says it does. As I stated in my followup to John, I screwed up SHMEM and SHLIB thikning about mmap() as the underlying implementation mechanism. > >You need to talk to the VM guys about fixing this. > > Right, and you should look at the code someday. No need to go off half-cocked. If you were as familiar with the code as you always expect me to be, then you would have realized that what I had was a labelling error, and instead of being an ad hominim attack, your response might have been: "Er... aren't you confusing mmap() and the shared memory implementation here?" To which I would have had to say: "Oh duh, pass the hat!" (Which is what I said to John). Regards, Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.