Return-Path: linux-nfs-owner@vger.kernel.org Received: from mga01.intel.com ([192.55.52.88]:4335 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760334Ab2FHXaO (ORCPT ); Fri, 8 Jun 2012 19:30:14 -0400 Date: Sat, 9 Jun 2012 02:31:27 +0300 From: "Kirill A. Shutemov" To: Andrew Morton Cc: Al Viro , Linus Torvalds , Boaz Harrosh , Tao Ma , Nick Piggin , "Dmitry V. Levin" , v9fs-developer@lists.sourceforge.net, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-afs@lists.infradead.org, linux-btrfs@vger.kernel.org, ceph-devel@vger.kernel.org, linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, codalist@TELEMANN.coda.cs.cmu.edu, ecryptfs@vger.kernel.org, osd-dev@open-osd.org, linux-ext4@vger.kernel.org, fuse-devel@lists.sourceforge.net, linux-mtd@lists.infradead.org, jfs-discussion@lists.sourceforge.net, logfs@logfs.org, linux-nfs@vger.kernel.org, linux-nilfs@vger.kernel.org, linux-ntfs-dev@lists.sourceforge.net, ocfs2-devel@oss.oracle.com, reiserfs-devel@vger.kernel.org Subject: Re: [RFC, PATCH, RESEND] fs: push rcu_barrier() from deactivate_locked_super() to filesystems Message-ID: <20120608233127.GB18981@otc-wbsnb-06> References: <1339191663-17693-1-git-send-email-kirill.shutemov@linux.intel.com> <20120608150253.e42464a6.akpm@linux-foundation.org> <20120608221446.GA18250@otc-wbsnb-06> <20120608152550.258d6a30.akpm@linux-foundation.org> <20120608222734.GT30000@ZenIV.linux.org.uk> <20120608153120.b722d7c3.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="3uo+9/B/ebqu+fSQ" In-Reply-To: <20120608153120.b722d7c3.akpm@linux-foundation.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: --3uo+9/B/ebqu+fSQ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Jun 08, 2012 at 03:31:20PM -0700, Andrew Morton wrote: > On Fri, 8 Jun 2012 23:27:34 +0100 > Al Viro wrote: >=20 > > On Fri, Jun 08, 2012 at 03:25:50PM -0700, Andrew Morton wrote: > >=20 > > > A neater implementation might be to add a kmem_cache* argument to > > > unregister_filesystem(). If that is non-NULL, unregister_filesystem() > > > does the rcu_barrier() and destroys the cache. That way we get to > > > delete (rather than add) a bunch of code from all filesystems and new > > > and out-of-tree filesystems cannot forget to perform the rcu_barrier(= ). > >=20 > > There's often enough more than one cache, so that one is no-go. >=20 > kmem_cache** ;) >=20 > Which filesystems have multiple inode caches? Multiple inode caches? No. Multiple caches with call_rcu() free? See btrfs or gfs2. --=20 Kirill A. Shutemov --3uo+9/B/ebqu+fSQ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJP0otPAAoJEAd+omnVudOM8pEP/j4da9wjUyer1zimYCUs0oA1 EQKJF+RlKs67b4j9eDRZKS/yDOC11CBemw333suupZugHnUmMrRIfbYw2c4vOsQs C8E3glDJ3i6plLquzD2tBNmrs2rFFSEoLXQEuzpDuN5BVKB4ifXqnuwxVX8/lxTN x3l81bt7sQvgO3OHL/DfuyVFsRG/N1qfaKJVjLhSFF971vPiz+xfn9uwiB8Be/Sa 28SBw4eVneaEZotHoNmDJmGH+LpRo0F5sy6gJNmh1VzK7eYN4pCr73f9tIL6x7XM GBF84tK8uN8iNPqVoMXh4HtLCbS+q6TvVpHCWqab9u/ajvLPP0vY+Osm6Ryw2Exn dnHjxqH9yyOsZmeHFP2osHNHbJMinKGX7iYoSAVuie5fTc27FkdyQkTS66KLpKGJ UHCZ/PeDfRtxVo+3gV8g0PQJCWJ2LHz7b4g3q4zK44pNZDeyslgS+gMMG881tCBp 1Qy9Xq6Hb8MlkrlDY43hz4suQRCibG1nBZK37Ni02fEcj6S2lD6gsu5J91gNEEkc 49Ry0vBmCMRT+Zsl4YP9PPKSfsPG+2oTpf06xV8V+rApqwZ6nKBpWqyuJuVVpxIT e/wamM+Ff6Ni6DVkXyXTO99wkSLHjdM+HL2MwhzQ38KMLrBAfzzZ8nGn67PahR/5 9q5U5UjNlz2F387CCYaK =It/C -----END PGP SIGNATURE----- --3uo+9/B/ebqu+fSQ--