Date: Mon, 26 May 2008 00:14:44 +0200 From: Pawel Jakub Dawidek <pjd@FreeBSD.org> To: Kris Kennaway <kris@FreeBSD.org> Cc: freebsd-fs@freebsd.org, d@delphij.net, Jeff Roberson <jeff@freebsd.org>, Jeff Roberson <jroberson@jroberson.net> Subject: Re: vfs.lookup_shared Message-ID: <20080525221444.GA8103@garage.freebsd.pl> In-Reply-To: <20080524085224.GL20868@hub.freebsd.org> References: <48376AA3.6090205@delphij.net> <20080523171509.K954@desktop> <20080524085224.GL20868@hub.freebsd.org>
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[-- Attachment #1 --] On Sat, May 24, 2008 at 08:52:24AM +0000, Kris Kennaway wrote: > > On Fri, May 23, 2008 at 05:16:16PM -1000, Jeff Roberson wrote: > > On Fri, 23 May 2008, Xin LI wrote: > > > > >-----BEGIN PGP SIGNED MESSAGE----- > > >Hash: SHA1 > > > > > >Hi, > > > > > >Is there any reason behind we don't have vfs.lookup_shared enabled by > > >default? > > > > We have discussed enabling it by default once the ffs shared lookup > > support is complete. Unfortunately ffs is still not 100% reliable. I > > want to verify that it's an ffs problem and not a problem with the vfs > > generic code which would effect all filesystems before we enable it by > > default. > > 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=1 on my ZFS-only laptop for more than a year now and never had a problem. Although it is only a laptop... -- Pawel Jakub Dawidek http://www.wheel.pl pjd@FreeBSD.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQFIOeTUForvXbEpPzQRAmwdAKDYSrfUaUXipjrjmxAy7ON0JCuvkACg4ygG M5ZqhmJiPxEJckyzjRzqu8g= =tPL2 -----END PGP SIGNATURE-----
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