Date: Mon, 2 Jul 2012 11:03:40 -0400 From: Alexander Kabaev <kabaev@gmail.com> To: Christoph Hellwig <hch@infradead.org> Cc: Attilio Rao <attilio@freebsd.org>, FreeBSD FS <freebsd-fs@freebsd.org>, freebsd-current@freebsd.org, "C. P. Ghost" <cpghost@cordula.ws>, Russell Cattelan <cattelan@thebarn.com> Subject: Re: MPSAFE VFS -- List of upcoming actions Message-ID: <20120702150339.GA7226@kan.dyndns.org> In-Reply-To: <20120702061219.GA16671@infradead.org> References: <CAJ-FndAJtFx_OhqzDvBSLQ5pEaX730oF8Tbyk%2BkYbz9y1KaXXA@mail.gmail.com> <CADGWnjXPtF1g1YXWEie3VAhamjj3D_MQ89Ep4zh3_6g8tGHzAA@mail.gmail.com> <CAJ-FndDRvZdzF00hO6TWJMASDmpgK4mkF3GFsacF3KBSB00YWw@mail.gmail.com> <20120702061219.GA16671@infradead.org>
next in thread | previous in thread | raw e-mail | index | archive | help
--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--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20120702150339.GA7226>