From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on yquem.inria.fr X-Spam-Level: X-Spam-Status: No, score=0.1 required=5.0 tests=AWL autolearn=disabled version=3.1.3 X-Original-To: caml-list@yquem.inria.fr Delivered-To: caml-list@yquem.inria.fr Received: from concorde.inria.fr (concorde.inria.fr [192.93.2.39]) by yquem.inria.fr (Postfix) with ESMTP id 4442BBC0A for ; Wed, 3 Jan 2007 00:46:22 +0100 (CET) Received: from moutng.kundenserver.de (moutng.kundenserver.de [212.227.126.171]) by concorde.inria.fr (8.13.6/8.13.6) with ESMTP id l02NkLSP007281 for ; Wed, 3 Jan 2007 00:46:22 +0100 Received: from [84.58.153.238] (helo=gate.lan.gerd-stolpmann.de) by mrelayeu.kundenserver.de (node=mrelayeu5) with ESMTP (Nemesis), id 0ML25U-1H1tKh41qL-0001Se; Wed, 03 Jan 2007 00:46:17 +0100 Received: from flakew.lan.gerd-stolpmann.de (fw.lan.gerd-stolpmann.de [192.168.1.1]) by gate.lan.gerd-stolpmann.de (Postfix) with ESMTP id A32CFC05F; Wed, 3 Jan 2007 00:46:15 +0100 (CET) Subject: Re: [Caml-list] ANNOUNCE : libsndfile-ocaml alpha From: Gerd Stolpmann To: Erik de Castro Lopo Cc: caml-list@yquem.inria.fr In-Reply-To: <20070103093701.3b827e81.mle+ocaml@mega-nerd.com> References: <20061222155407.ebe6c272.mle+ocaml@mega-nerd.com> <45923DC2.9000504@ujf-grenoble.fr> <20061227211046.656615d0.mle+ocaml@mega-nerd.com> <20061231080756.66e89d6c.mle+ocaml@mega-nerd.com> <1167535885.27287.66.camel@rosella.wigram> <20061231152305.694fd3e9.mle+ocaml@mega-nerd.com> <20061231110831.GA21198@furbychan.cocan.org> <20070101095114.911ca90d.mle+ocaml@mega-nerd.com> <4599205A.7050802@laposte.net> <20070102065845.c6558b18.mle+ocaml@mega-nerd.com> <1167699073.13679.15.camel@rosella.wigram> <20070102121424.07da295b.mle+ocaml@mega-nerd.com> <1167765505.5341.12.camel@rosella.wigram> <20070103093701.3b827e81.mle+ocaml@mega-nerd.com> Content-Type: text/plain Date: Wed, 03 Jan 2007 00:46:14 +0100 Message-Id: <1167781575.8359.21.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.6.1 Content-Transfer-Encoding: 7bit X-Provags-ID: kundenserver.de abuse@kundenserver.de login:a6865a839c0178d9aa0ce41878507ea2 X-Miltered: at concorde with ID 459AEECD.002 by Joe's j-chkmail (http://j-chkmail . ensmp . fr)! X-Spam: no; 0.00; gerd:01 stolpmann:01 buffer:01 alignment:01 bigarray:01 gerd:01 stolpmann:01 viktoriastr:01 64293:01 darmstadt:01 6151:01 6151:01 unix:01 caml-list:01 btw:02 Am Mittwoch, den 03.01.2007, 09:37 +1100 schrieb Erik de Castro Lopo: > BTW, anyone mmaping files on Linux for performance reasons should > be aware that Linus himself doesn't think mmap will have any > performance improvement over read: > > http://www.cs.helsinki.fi/linux/linux-kernel/2001-40/1661.html Just a quick and somehow interesting observation: Linus assumes that the read buffer is page-aligned in this comparison, something you cannot expect in most higher languages (of course you can arrange that in libsndfile - did you?). That reminds me that the OS guys live in another world. Would be interesting which function wins if you compare Unix.read (which does not care about alignment, and does an extra copy) with Bigarray.mmap. Gerd -- ------------------------------------------------------------ Gerd Stolpmann * Viktoriastr. 45 * 64293 Darmstadt * Germany gerd@gerd-stolpmann.de http://www.gerd-stolpmann.de Phone: +49-6151-153855 Fax: +49-6151-997714 ------------------------------------------------------------