From owner-freebsd-arch@FreeBSD.ORG Thu Mar 1 14:16:02 2012 Return-Path: Delivered-To: arch@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E136D106564A; Thu, 1 Mar 2012 14:16:02 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from mail.zoral.com.ua (mx0.zoral.com.ua [91.193.166.200]) by mx1.freebsd.org (Postfix) with ESMTP id 33CD68FC15; Thu, 1 Mar 2012 14:16:01 +0000 (UTC) Received: from skuns.kiev.zoral.com.ua (localhost [127.0.0.1]) by mail.zoral.com.ua (8.14.2/8.14.2) with ESMTP id q21EFsRB090647; Thu, 1 Mar 2012 16:15:54 +0200 (EET) (envelope-from kostikbel@gmail.com) Received: from deviant.kiev.zoral.com.ua (kostik@localhost [127.0.0.1]) by deviant.kiev.zoral.com.ua (8.14.5/8.14.5) with ESMTP id q21EFrpx074450; Thu, 1 Mar 2012 16:15:53 +0200 (EET) (envelope-from kostikbel@gmail.com) Received: (from kostik@localhost) by deviant.kiev.zoral.com.ua (8.14.5/8.14.5/Submit) id q21EFrg1074449; Thu, 1 Mar 2012 16:15:53 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: deviant.kiev.zoral.com.ua: kostik set sender to kostikbel@gmail.com using -f Date: Thu, 1 Mar 2012 16:15:53 +0200 From: Konstantin Belousov To: Pawel Jakub Dawidek Message-ID: <20120301141553.GT55074@deviant.kiev.zoral.com.ua> References: <20120203193719.GB3283@deviant.kiev.zoral.com.ua> <20120225151334.GH1344@garage.freebsd.pl> <20120225194630.GI1344@garage.freebsd.pl> <20120301111624.GB30991@reks> <20120301141247.GE1336@garage.freebsd.pl> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="nlOp58TzLcTjnOVc" Content-Disposition: inline In-Reply-To: <20120301141247.GE1336@garage.freebsd.pl> User-Agent: Mutt/1.4.2.3i X-Virus-Scanned: clamav-milter 0.95.2 at skuns.kiev.zoral.com.ua X-Virus-Status: Clean X-Spam-Status: No, score=-4.0 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on skuns.kiev.zoral.com.ua Cc: Attilio Rao , arch@FreeBSD.org, Gleb Kurtsou Subject: Re: Prefaulting for i/o buffers X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 01 Mar 2012 14:16:03 -0000 --nlOp58TzLcTjnOVc Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Mar 01, 2012 at 03:12:47PM +0100, Pawel Jakub Dawidek wrote: > On Thu, Mar 01, 2012 at 01:16:24PM +0200, Gleb Kurtsou wrote: > > On (25/02/2012 20:46), Pawel Jakub Dawidek wrote: > > > - "Every file system needs cache. Let's make it general, so that all = file > > > systems can use it!" Well, for VFS each file system is a separate > > > entity, which is not the case for ZFS. ZFS can cache one block only > > > once that is used by one file system, 10 clones and 100 snapshots, > > > which all are separate mount points from VFS perspective. > > > The same block would be cached 111 times by the buffer cache. > >=20 > > Hmm. But this one is optional. Use vop_cachedlookup (or call > > cache_entry() on your own), add a number of cache_prune calls. It's > > pretty much library-like design you describe below. >=20 > Yes, namecache is already library-like, but I was talking about the > buffer cache. I managed to bypass it eventually with suggestions from > ups@, but for a long time I was sure it isn't at all possible. I am quite curious, in which way buffer layer is mandatory ? --nlOp58TzLcTjnOVc Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (FreeBSD) iEYEARECAAYFAk9PhJkACgkQC3+MBN1Mb4gPEACgz/9StyTUKFfToGQFVaUgJWpq SI8An0aCnA/fz8EySQ7u1IrO3JxLSIRr =4S1J -----END PGP SIGNATURE----- --nlOp58TzLcTjnOVc--