From owner-freebsd-fs@FreeBSD.ORG Sun May 25 22:34:22 2008 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 1E14A106576D; Sun, 25 May 2008 22:34:22 +0000 (UTC) (envelope-from pjd@garage.freebsd.pl) Received: from mail.garage.freebsd.pl (chello087206046210.chello.pl [87.206.46.210]) by mx1.freebsd.org (Postfix) with ESMTP id 877818FC18; Sun, 25 May 2008 22:34:18 +0000 (UTC) (envelope-from pjd@garage.freebsd.pl) Received: by mail.garage.freebsd.pl (Postfix, from userid 65534) id 16BEB45C9B; Mon, 26 May 2008 00:14:52 +0200 (CEST) Received: from localhost (chello087206046210.chello.pl [87.206.46.210]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.garage.freebsd.pl (Postfix) with ESMTP id D4D86456B1; Mon, 26 May 2008 00:14:45 +0200 (CEST) Date: Mon, 26 May 2008 00:14:44 +0200 From: Pawel Jakub Dawidek To: Kris Kennaway Message-ID: <20080525221444.GA8103@garage.freebsd.pl> References: <48376AA3.6090205@delphij.net> <20080523171509.K954@desktop> <20080524085224.GL20868@hub.freebsd.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="SUOF0GtieIMvvwua" Content-Disposition: inline In-Reply-To: <20080524085224.GL20868@hub.freebsd.org> User-Agent: Mutt/1.4.2.3i X-PGP-Key-URL: http://people.freebsd.org/~pjd/pjd.asc X-OS: FreeBSD 8.0-CURRENT i386 X-Spam-Checker-Version: SpamAssassin 3.0.4 (2005-06-05) on mail.garage.freebsd.pl X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=BAYES_00 autolearn=ham version=3.0.4 Cc: freebsd-fs@freebsd.org, d@delphij.net, Jeff Roberson , Jeff Roberson Subject: Re: vfs.lookup_shared X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 25 May 2008 22:34:22 -0000 --SUOF0GtieIMvvwua Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sat, May 24, 2008 at 08:52:24AM +0000, Kris Kennaway wrote: >=20 > On Fri, May 23, 2008 at 05:16:16PM -1000, Jeff Roberson wrote: > > On Fri, 23 May 2008, Xin LI wrote: > >=20 > > >-----BEGIN PGP SIGNED MESSAGE----- > > >Hash: SHA1 > > > > > >Hi, > > > > > >Is there any reason behind we don't have vfs.lookup_shared enabled by > > >default? > >=20 > > We have discussed enabling it by default once the ffs shared lookup=20 > > support is complete. Unfortunately ffs is still not 100% reliable. I= =20 > > want to verify that it's an ffs problem and not a problem with the vfs= =20 > > generic code which would effect all filesystems before we enable it by= =20 > > default. >=20 > Also, until Attilio's recent lockmgr work, shared lockmgr locks were > starving exclusive lockmgr lock requests, leading to performance > problems on some workloads with the only filesystem that supported > shared locking (NFS). This is now fixed though. ZFS also supports shared locking and shared lookups. I've vfs.lookup_shared=3D1 on my ZFS-only laptop for more than a year now and never had a problem. Although it is only a laptop... --=20 Pawel Jakub Dawidek http://www.wheel.pl pjd@FreeBSD.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! --SUOF0GtieIMvvwua Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQFIOeTUForvXbEpPzQRAmwdAKDYSrfUaUXipjrjmxAy7ON0JCuvkACg4ygG M5ZqhmJiPxEJckyzjRzqu8g= =tPL2 -----END PGP SIGNATURE----- --SUOF0GtieIMvvwua--