From owner-freebsd-stable@FreeBSD.ORG Mon Apr 3 19:50:11 2006 Return-Path: X-Original-To: freebsd-stable@FreeBSD.org Delivered-To: freebsd-stable@FreeBSD.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3875B16A43A; Mon, 3 Apr 2006 19:50:10 +0000 (UTC) (envelope-from sfrost@snowman.net) Received: from ns.snowman.net (ns.snowman.net [66.92.160.21]) by mx1.FreeBSD.org (Postfix) with ESMTP id 0C6AF43D6A; Mon, 3 Apr 2006 19:49:32 +0000 (GMT) (envelope-from sfrost@snowman.net) Received: by ns.snowman.net (Postfix, from userid 1000) id 9DF7217B08; Mon, 3 Apr 2006 15:50:18 -0400 (EDT) Date: Mon, 3 Apr 2006 15:50:18 -0400 From: Stephen Frost To: Tom Lane Message-ID: <20060403195018.GG4474@ns.snowman.net> Mail-Followup-To: Tom Lane , Robert Watson , "Marc G. Fournier" , Kris Kennaway , freebsd-stable@FreeBSD.org, pgsql-hackers@postgresql.org References: <26985.1144029657@sss.pgh.pa.us> <20060402231232.C947@ganymede.hub.org> <27148.1144030940@sss.pgh.pa.us> <20060402232832.M947@ganymede.hub.org> <20060402234459.Y947@ganymede.hub.org> <27417.1144033691@sss.pgh.pa.us> <20060403164139.D36756@fledge.watson.org> <14654.1144082224@sss.pgh.pa.us> <20060403174043.S76562@fledge.watson.org> <14905.1144084059@sss.pgh.pa.us> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="xtjQnVSMpkrbsJsT" Content-Disposition: inline In-Reply-To: <14905.1144084059@sss.pgh.pa.us> X-Editor: Vim http://www.vim.org/ X-Info: http://www.snowman.net X-Operating-System: Linux/2.4.24ns.3.0 (i686) X-Uptime: 15:44:14 up 296 days, 11:50, 5 users, load average: 0.00, 0.03, 0.00 User-Agent: Mutt/1.5.11 Cc: freebsd-stable@FreeBSD.org, "Marc G. Fournier" , pgsql-hackers@postgresql.org, Robert Watson , Kris Kennaway Subject: Re: [HACKERS] semaphore usage "port based"? 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: Mon, 03 Apr 2006 19:50:11 -0000 --xtjQnVSMpkrbsJsT Content-Type: text/plain; charset=us-ascii Content-Disposition: inline * Tom Lane (tgl@sss.pgh.pa.us) wrote: > BTW, Marc, it occurs to me that a workaround for you would be to create > a separate userid for postgres to run under in each jail; then the > regular protection mechanisms would prevent the different postmasters > from interfering with each others' semaphore sets. But I think that > workaround just makes it even clearer that the jail mechanism isn't > behaving very sanely. Just to toss it in there, I do this on some systems where we use Linux VServers. It's just so that when I'm looking at a process list across the whole system it's easy to tell which processes are inside which vservers (since the only thing which should be running in a given vserver is a single Postgres instance which should only be running with the uid/gid corresponding to that vserver, and that uid/gid is recorded in the host passwd file with a name associated with it since that's the passwd file used when looking at all pids). I also just double-checked with the Linux VServer folks and they confirm that IPC inside the vserver are isolated from all the other IPCs on the system. Thanks, Stephen --xtjQnVSMpkrbsJsT Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (GNU/Linux) iD8DBQFEMXx6rzgMPqB3kigRArK1AJ43NLH2KgS2LlDu2R/Ve8e3+EZisQCgglFE xWfDo3k/xSbIRvAo8yEw0Ys= =tH0M -----END PGP SIGNATURE----- --xtjQnVSMpkrbsJsT--