From owner-freebsd-current@FreeBSD.ORG Mon Jul 2 15:03:45 2012 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D5FFF106566B; Mon, 2 Jul 2012 15:03:45 +0000 (UTC) (envelope-from kabaev@gmail.com) Received: from mail-qc0-f182.google.com (mail-qc0-f182.google.com [209.85.216.182]) by mx1.freebsd.org (Postfix) with ESMTP id 560408FC14; Mon, 2 Jul 2012 15:03:45 +0000 (UTC) Received: by qcsg15 with SMTP id g15so3402741qcs.13 for ; Mon, 02 Jul 2012 08:03:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; bh=kDkWVGa3N+2gt5YKidDiC1CmwxYnsun92iAZTZJbBh4=; b=rhdJoMce//KjShpj72Cee4o2cJh7xTMaXZt+Y1IIcSSYdNDf4bvmzlGRViFLZ/CVbh i5S1GNiPXZWanJZbHOnvA/5gvPZBBwe7VhM2ZTHJ1ssi/6NDc/iD/g9c5txr4pkTkVdv OtoEhWr8DuLNxK8Pe7YpUnX6iTBtIr7tcQL2n0zgJrcb5m/S4+bjLVzDEWdvslcvZTkC miQ5M1eeGBq/MbRpitIHjVB3c7of6kFP68LCcOpaNI1TiH6A/hEDmA9ZLCsqLTdltNDR Mh7IKLRjwLDKcUYcre/AMbLGNp1MVcdWgs3sGgNf42VyLy4tAU7I8e3hHODA920EvQLU k6tA== Received: by 10.229.135.18 with SMTP id l18mr6862575qct.156.1341241424614; Mon, 02 Jul 2012 08:03:44 -0700 (PDT) Received: from kan.dyndns.org (c-24-63-226-98.hsd1.ma.comcast.net. [24.63.226.98]) by mx.google.com with ESMTPS id dz4sm31724960qab.4.2012.07.02.08.03.42 (version=TLSv1/SSLv3 cipher=OTHER); Mon, 02 Jul 2012 08:03:43 -0700 (PDT) Date: Mon, 2 Jul 2012 11:03:40 -0400 From: Alexander Kabaev To: Christoph Hellwig Message-ID: <20120702150339.GA7226@kan.dyndns.org> References: <20120702061219.GA16671@infradead.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="EVF5PPMfhYS0aIcm" Content-Disposition: inline In-Reply-To: <20120702061219.GA16671@infradead.org> User-Agent: Mutt/1.5.21 (2010-09-15) Cc: Attilio Rao , FreeBSD FS , freebsd-current@freebsd.org, "C. P. Ghost" , Russell Cattelan Subject: Re: MPSAFE VFS -- List of upcoming actions X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 02 Jul 2012 15:03:46 -0000 --EVF5PPMfhYS0aIcm Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Jul 02, 2012 at 02:12:20AM -0400, Christoph Hellwig wrote: > On Sun, Jul 01, 2012 at 03:52:05PM +0200, Attilio Rao wrote: > > anything by SoC involved people about NTFS and certainly I don't see a > > plan to get XFS locked. >=20 > Stupid question, but what amount of locking does XFS in FreeBSD still > need? I'm one of the maintainer of XFS on Linux, and while I know > FreeBSD imported a really old version compared to the current one the > codebases on IRIX and later Linux never relied on any global Giant-style > locking. So if there is anything to fix it would be the in the small > bits of FreeBSD-specific code. >=20 When I stopped being interested in XFS, I left is marked as non-MPSAFE entirely because of the lack of proper testing and because VFS locking was still evolving, there was no officially proper way of locking the FS and no other FS in the tree was MPSAFE. At that time the only problematic area was around inode instantiation, but sereval other lockingi changes have made it into the tree since then, namely ones that deal with insmntque and also VOP_LOOKUP changes. To mark XFS MPSAFE, one needs to simply audit the code and make sure it still makse sense for today= 's VFS, which is not a huge amount of work. One step further woule be to take most of the XFS from under the exclusive vnode locking to improve the performance. And there is a third option - just let current XFS port die and start with newer version. --=20 Alexander Kabaev --EVF5PPMfhYS0aIcm Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (FreeBSD) iD8DBQFP8bhLQ6z1jMm+XZYRAhpNAJ9/wX+/YBqya26vJdUdSl+NrlyOjwCg3K2J ursmLw9qFXWb8eIvglCWxJI= =q7N/ -----END PGP SIGNATURE----- --EVF5PPMfhYS0aIcm--