From owner-freebsd-hackers@FreeBSD.ORG Mon Oct 8 08:45:29 2012 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id A32A1106564A for ; Mon, 8 Oct 2012 08:45:29 +0000 (UTC) (envelope-from roam@ringlet.net) Received: from nimbus.fccf.net (nimbus.fccf.net [77.77.144.35]) by mx1.freebsd.org (Postfix) with ESMTP id 4BE678FC1B for ; Mon, 8 Oct 2012 08:45:29 +0000 (UTC) Received: from straylight.m.ringlet.net (unknown [78.90.13.150]) by nimbus.fccf.net (Postfix) with ESMTPSA id 03BC1952 for ; Mon, 8 Oct 2012 11:38:16 +0300 (EEST) Received: from roam (uid 1000) (envelope-from roam@ringlet.net) id 316002 by straylight.m.ringlet.net (DragonFly Mail Agent); Mon, 08 Oct 2012 11:38:14 +0300 Date: Mon, 8 Oct 2012 11:38:14 +0300 From: Peter Pentchev To: Wojciech Puchar Message-ID: <20121008083814.GA5830@straylight.m.ringlet.net> Mail-Followup-To: Wojciech Puchar , Tim Kientzle , freebsd-hackers@freebsd.org, Brandon Falk References: <5069C9FC.6020400@brandonfa.lk> <324B736D-8961-4E44-A212-2ECF3E60F2A0@kientzle.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="n8g4imXOkfNTN/H1" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Cc: Brandon Falk , freebsd-hackers@freebsd.org Subject: Re: SMP Version of tar X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 08 Oct 2012 08:45:29 -0000 --n8g4imXOkfNTN/H1 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Oct 08, 2012 at 08:38:33AM +0200, Wojciech Puchar wrote: > >>gzip cannot - it is single stream. > > > >gunzip commutes with cat, so gzip > >compression can be multi-threaded > >by compressing separate blocks and > >concatenating the result. >=20 > right. but resulting file format must be different. Not necessarily. If I understand correctly what Tim means, he's talking about an in-memory compression of several blocks by several separate threads, and then - after all the threads have compressed their respective blocks - writing out the result to the output file in order. Of course, this would incur a small penalty in that the dictionary would not be reused between blocks, but it might still be worth it. G'luck, Peter --=20 Peter Pentchev roam@ringlet.net roam@FreeBSD.org peter@packetscale.com PGP key: http://people.FreeBSD.org/~roam/roam.key.asc Key fingerprint FDBA FD79 C26F 3C51 C95E DF9E ED18 B68D 1619 4553 Hey, out there - is it *you* reading me, or is it someone else? --n8g4imXOkfNTN/H1 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBCAAGBQJQcpDwAAoJEGUe77AlJ98TLBMP/jQ74ESXef5g/Uedklzi/PXI wsgP8BFBzHwldymZnH/lRMYKLUbjYka+HIrf/hrdLBRVu4/uyYP5+3aYD2DuFxHP gONtqrBo9FSuXVxk9fB8tfldoM4rudovgBZbUHkm+mONRtMkyQ4diBEvLnJHUKmL oiphw/QjOUveuxssnFiOBVu9x07yWORNNarVT4xl7otjhL+G7aapvU+NqVvSidzG aq8ftYAgo1npyoZubSVb0KHHASRAryLz3iMSW3tJSg9mMbReZbxZ60no0X3X0c8Y 9fs8gP3eH2T2R8rxh/A9+ursgC/gSDNsSIQo3ta0eJ+Rp9U+7il3Y3K7BlsltmNg yxdhQjF6PRDCpt3KGS10oijNdHpmKrOGBH0pY9nJoDUlSYGIjScHlqX7dY4vbtLO R+3w9f33iowMWG1skY0fcbCZnljpQyqIwRiC1iCLDn/qpPAyG9bw4ZAdfbF27P7d sEUaFe2Sj5hEoDkLuArXOIcOokLNQhGcf5nZmg9uCgbnHibfk65d053L7zeexGqQ oxBl63HHx/Xh25qEzndfVrDahDgxS8+vsU5BKlA12VPBq7Kg1CB+pFKme7jHaFcW JjtVU39/ml/pkINEMw5HL/T79HdrN2I4jkiWKlCsq3jsySKVH8pcEA8+Og82nvcD lGHdNT7Zd3X0qM90dix9 =yNTU -----END PGP SIGNATURE----- --n8g4imXOkfNTN/H1--