From owner-freebsd-hackers@FreeBSD.ORG Tue Jan 18 20:32:57 2005 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 0C37D16A4CE for ; Tue, 18 Jan 2005 20:32:57 +0000 (GMT) Received: from stella.fs.ei.tum.de (stella.fs.ei.tum.de [129.187.54.7]) by mx1.FreeBSD.org (Postfix) with ESMTP id D4CF943D39 for ; Tue, 18 Jan 2005 20:32:53 +0000 (GMT) (envelope-from corecode@fs.ei.tum.de) Received: from localhost (localhost [127.0.0.1]) by localhost.fs.ei.tum.de (Postfix) with ESMTP id 814D95E6; Tue, 18 Jan 2005 21:32:50 +0100 (CET) Received: from [10.150.180.180] (r180180.olydorf.swh.mhn.de [10.150.180.180]) (using SSLv3 with cipher RC4-MD5 (128/128 bits)) (Client did not present a certificate) by stella.fs.ei.tum.de (Postfix) with ESMTP id 539085E5; Tue, 18 Jan 2005 21:32:46 +0100 (CET) From: Simon 'corecode' Schubert To: freebsd-hackers@freebsd.org Date: Tue, 18 Jan 2005 21:32:35 +0100 User-Agent: KMail/1.7.1 References: In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart4532779.pnLIk1ZdN4"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Message-Id: <200501182132.44384.corecode@fs.ei.tum.de> X-Virus-Scanned: by AMaViS 0.3.12 cc: Street Chaman Subject: Re: Kernel mode programming -precisions X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 18 Jan 2005 20:32:57 -0000 --nextPart4532779.pnLIk1ZdN4 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Tuesday, 18. January 2005 20:54, Street Chaman wrote: > Actually, my soft is a kind of interactive filter: it takes a lot of imput > parameters (from keyboard at the moment, but as soon as i've understood h= ow > it works, i will increase the number of supported io devices); treats it = in > a particular way and produces an output. This 'particular way' requires a > lot of clock cycle, so speed is my first problem; (that's part of reason > why everything is directly written in assembly). I've already buffered > input and output, but only as far at it was possible: since loop (X) input > could affect loop (X-1) general data manipulation, and change output, it > must be detected quickly. The time needed to read/write is still to long. > When CPU is waiting on some new data, he cannot preform any other > operation, and freezes data manipultion; that's why I'm looking for a new > way to in/output the soft... you don't describe where the data comes from and where to goes to. if it's = a=20 file, you might want to use memory mapped files (mmap(2)), which will give= =20 you (about) the least overhead in reading/writing which can be achieved. so your problem more sounds like a cpu-bound than an io-bound application.= =20 details could help to understand and give advice. oh yes, if your "particular way" is so complex and critical that it needs t= o=20 be written in assembler you might even consider using an FPGA extension, bu= t=20 that's a completely other way of solving speed problems. furthermore that's= =20 just of interest if your algorithm is vectorizable, and it didn't sound lik= e=20 it. cheers simon =2D-=20 /"\ \ / \ ASCII Ribbon Campaign / \ Against HTML Mail and News --nextPart4532779.pnLIk1ZdN4 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.6 (FreeBSD) iD8DBQBB7XJsr5S+dk6z85oRAqltAJ94vQxOs+F4Reir90gYgtO+MgTPsACgzK37 4c2zxRBoPXc+62Fd7v1bumc= =DcO4 -----END PGP SIGNATURE----- --nextPart4532779.pnLIk1ZdN4--