From owner-freebsd-stable@FreeBSD.ORG Tue Oct 16 09:42:37 2007 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 558CE16A41A for ; Tue, 16 Oct 2007 09:42:37 +0000 (UTC) (envelope-from peterjeremy@optushome.com.au) Received: from turion.vk2pj.dyndns.org (c220-239-20-82.belrs4.nsw.optusnet.com.au [220.239.20.82]) by mx1.freebsd.org (Postfix) with ESMTP id ED9A613C4A7 for ; Tue, 16 Oct 2007 09:42:36 +0000 (UTC) (envelope-from peterjeremy@optushome.com.au) Received: from turion.vk2pj.dyndns.org (localhost.vk2pj.dyndns.org [127.0.0.1]) by turion.vk2pj.dyndns.org (8.14.1/8.14.1) with ESMTP id l9G9gYaE002089; Tue, 16 Oct 2007 19:42:34 +1000 (EST) (envelope-from peter@turion.vk2pj.dyndns.org) Received: (from peter@localhost) by turion.vk2pj.dyndns.org (8.14.1/8.14.1/Submit) id l9G9gYau002088; Tue, 16 Oct 2007 19:42:34 +1000 (EST) (envelope-from peter) Date: Tue, 16 Oct 2007 19:42:34 +1000 From: Peter Jeremy To: William LeFebvre Message-ID: <20071016094234.GM1184@turion.vk2pj.dyndns.org> References: <008801c80e66$7be49490$0c00a8c0@Artem> <471367F2.7050303@lefebvre.org> <037501c80f3d$69120730$0c00a8c0@Artem> <471398BB.30405@lefebvre.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="Km1U/tdNT/EmXiR1" Content-Disposition: inline In-Reply-To: <471398BB.30405@lefebvre.org> X-PGP-Key: http://members.optusnet.com.au/peterjeremy/pubkey.asc User-Agent: Mutt/1.5.16 (2007-06-09) Cc: freebsd-stable@freebsd.org Subject: Re: Question about 'top' values on memory usage, now threads X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 16 Oct 2007 09:42:37 -0000 --Km1U/tdNT/EmXiR1 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 2007-Oct-15 12:43:39 -0400, William LeFebvre wrote: >Whether there is actual swapping going on or not, processes will still nee= d=20 >swap space. There needs to be a backing store for every page that's in=20 >physical memory. This isn't true for FreeBSD. You can even totally disable paging/swapping with the config option "NO_SWAPPING" if you want. FreeBSD allocates swap space on an "as needed" basis, rather than pre-allocating swap. The advantage is that a process can request virtually unlimited amounts of memory via sbrk(2), mmap(2) or malloc(3). The downside is that a process may be killed without notice when it writes to some previously allocated but unused part of its address space. See the archives for the full bikeshed. --=20 Peter Jeremy --Km1U/tdNT/EmXiR1 Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (FreeBSD) iD8DBQFHFIeK/opHv/APuIcRAoE2AKCoLsAOgaudTZDIVIgl9L9NNpMx6QCdHf1+ ygC73MLtgKilxCdi2Z2+57c= =eHd/ -----END PGP SIGNATURE----- --Km1U/tdNT/EmXiR1--