From owner-freebsd-arch@FreeBSD.ORG Mon Mar 11 21:12:08 2013 Return-Path: Delivered-To: arch@freebsd.org Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id 6CB2726D for ; Mon, 11 Mar 2013 21:12:08 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) by mx1.freebsd.org (Postfix) with ESMTP id C8CAF1D7 for ; Mon, 11 Mar 2013 21:12:07 +0000 (UTC) Received: from tom.home (kostik@localhost [127.0.0.1]) by kib.kiev.ua (8.14.6/8.14.6) with ESMTP id r2BLBwmv041437; Mon, 11 Mar 2013 23:11:58 +0200 (EET) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.8.0 kib.kiev.ua r2BLBwmv041437 Received: (from kostik@localhost) by tom.home (8.14.6/8.14.6/Submit) id r2BLBwX1041436; Mon, 11 Mar 2013 23:11:58 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Mon, 11 Mar 2013 23:11:58 +0200 From: Konstantin Belousov To: Lev Serebryakov Subject: Re: Unmapped buffers: to be merged in several days Message-ID: <20130311211158.GE3794@kib.kiev.ua> References: <20130311091852.GR3794@kib.kiev.ua> <86k3pe1cl3.fsf@ds4.des.no> <20130311182454.GX3794@kib.kiev.ua> <329178079.20130312010425@serebryakov.spb.ru> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="JU1P3uBe1BU9Y2xT" Content-Disposition: inline In-Reply-To: <329178079.20130312010425@serebryakov.spb.ru> User-Agent: Mutt/1.5.21 (2010-09-15) X-Spam-Status: No, score=-2.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FREEMAIL_FROM,NML_ADSP_CUSTOM_MED autolearn=no version=3.3.2 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on tom.home Cc: Dag-Erling Sm??rgrav , arch@freebsd.org X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 11 Mar 2013 21:12:08 -0000 --JU1P3uBe1BU9Y2xT Content-Type: text/plain; charset=koi8-r Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Mar 12, 2013 at 01:04:25AM +0400, Lev Serebryakov wrote: > Hello, Konstantin. > You wrote 11 =CD=C1=D2=D4=C1 2013 =C7., 22:24:54: >=20 > KB> If the class does need to access the bio data, to be marked > KB> unmapped-processing, the class should be rewritten. Now, the class > KB> should verify is the bio passed is mapped or not, and process the pag= es > KB> passed in the bio_ma array instead of bio_data. The involved example = is > KB> sys/dev/md/md.c. > Will GEOM class, which needs to touch data (like raid3 or my off-tree > raid5), benefit from conversion, compare to generic mechanism, > provided for not-converted by your patch? First, what do you mean by 'benefit'. Answer would obviously depend on the criteria. Second, I do not think that any wizard can usefully answer this question, for usual criteria like speed or code maintanability. FWIW, I tried to get an Intel documentation for IOAT engine which should allow to perform the XOR checksumming of the unmapped buffers, suitable for e.g. hardware-assisted software raid5, but did not succeeded. --JU1P3uBe1BU9Y2xT Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (FreeBSD) iQIcBAEBAgAGBQJRPkieAAoJEJDCuSvBvK1BU58P/R1NuIJ5JnEjBO5jQ6dOrDV0 RiyFHXaHZeHIEQsPe5mtgCjOLcRD2OBicTgnjJK/el8UBsuF9LrUpkX76ATfoj10 ibMi8oB61ZR1ub9llmXlEA1vykZxV1CbODPhokAQLvf3bEJLxOLLIEajtNsmlbkE sBB9fP5KcrHIfv57Ya/mnVEeQo9tC3NPsmXdq/fJZu7wj7zwU+nSMX8jVqz2clr5 18A6stx2in0MKueYEhAtESq1oYGTHSEV7GXiowFq/Gj7mHy30I4RVXqoOGEsAi/I Rv7G+zRfk9cm2o+2lug8+PirYnYK7Zslrd5t8/7LhS8zIuHCNXQCCs42EMPJ8rPH 5GzQk6keDqlZxFBaIxSk6Ni2NDIiCWkcUce3vrupTsOqfyJGpRyuUnR6Hn2S73kV C2zHD+QyHrNRRdpD/yR355LbiVRVqok26abE4s4ldgthv7kacTNjkBdNWnLXEU2z iScoVsL7mkrhLtWSOtY5665f/lcAgtvkoO6F6WEt3Hw0dSCxDkHaYnPAfZAiZWi+ bFpmL98HcGMH+dObBWIQupAOFPO/prrf1nwYVSBTK4se5NZghcdVjAu1Sf3m+tVo 9hWYWaa0Knp0/RGxZ90Aj6tb6mJ9/X53wLG0wgZYWqiCoMYmwO2APKepgrjhwVMF wqfbwFArOE+HLotLOiqi =J1br -----END PGP SIGNATURE----- --JU1P3uBe1BU9Y2xT--