From owner-freebsd-small Sat Feb 10 23:17:51 2001 Delivered-To: freebsd-small@freebsd.org Received: from workhorse.iMach.com (workhorse.iMach.com [206.127.77.89]) by hub.freebsd.org (Postfix) with ESMTP id 98ED837B401 for ; Sat, 10 Feb 2001 23:17:34 -0800 (PST) Received: from localhost (forrestc@localhost) by workhorse.iMach.com (8.9.3/8.9.3) with ESMTP id AAA18867 for ; Sun, 11 Feb 2001 00:13:25 -0700 (MST) Date: Sun, 11 Feb 2001 00:13:24 -0700 (MST) From: "Forrest W. Christian" To: freebsd-small@freebsd.org Subject: Sans-Swap VM Subsystem Questions Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-small@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG I asked this (phrased differently) over in -hackers as I thought the people who would know were likely among that crowd. I didn't get a response, and in retrospect, it's probably better asked here anyways. I'm currently working on a system with a rather large flash disk, Limited RAM, and absolutely no swap. Some background first: The FreeBSD VM subsystem in it's "normal" state understands that if it loads a program off of disk and then gets tight on memory that it can free the memory consumed by the non-changed code of the program without swapping to disk as it knows that it can just re-load it from the disk where it found it. In my system, since I don't have swap, and limited memory, I would like to ensure that the above described piece of the VM subsystem continues to work. That way, it can effectively "run from flash" if necessary. However, as memory is (always) tight in this environment, I would also like to remove the SWAPPING code (as opposed to the "free" code described above) from the kernel. So, my question was what, if anything, does "options NO_SWAPPING" (or whatever the exact option is) do in regards to the vm "free" chunk of code? I'd also like to hear people's experience with running with and without the two swap-related kernel variables turned on without swap. I realize that the general consensus is to "enable" both delay and disable swap pagesouts. - Forrest W. Christian (forrestc@imach.com) AC7DE ---------------------------------------------------------------------- iMach, Ltd., P.O. Box 5749, Helena, MT 59604 http://www.imach.com Solutions for your high-tech problems. (406)-442-6648 ---------------------------------------------------------------------- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-small" in the body of the message