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=0.0 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 mail3-relais-sop.national.inria.fr (mail3-relais-sop.national.inria.fr [192.134.164.104]) by yquem.inria.fr (Postfix) with ESMTP id 8B193BBC1 for ; Mon, 21 Apr 2008 17:00:35 +0200 (CEST) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AjUDAEdJDEjUnw6Gb2dsb2JhbACCL48oAQwFAgUHGJgn X-IronPort-AV: E=Sophos;i="4.25,690,1199660400"; d="scan'208";a="11719129" Received: from pih-relay08.plus.net ([212.159.14.134]) by mail3-smtp-sop.national.inria.fr with ESMTP; 21 Apr 2008 17:00:21 +0200 Received: from [80.229.56.224] (helo=beast.local) by pih-relay08.plus.net with esmtp (Exim) id 1JnxVE-0002Ro-PE for caml-list@yquem.inria.fr; Mon, 21 Apr 2008 16:00:20 +0100 From: Jon Harrop Organization: Flying Frog Consultancy Ltd. To: caml-list@yquem.inria.fr Subject: Re: [Caml-list] The closing gap (warning: long, inflammatory rant) Date: Mon, 21 Apr 2008 15:44:08 +0100 User-Agent: KMail/1.9.9 References: <20080421131151.GA16777@annexia.org> In-Reply-To: <20080421131151.GA16777@annexia.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Message-Id: <200804211544.08897.jon@ffconsultancy.com> X-Plusnet-Relay: 9d517df18c322d18d892892f2927e7c4 X-Spam: no; 0.00; 0200,:01 berke:01 durak:01 niches:01 ocaml:01 frog:98 garbage:01 wrote:01 wrote:01 typing:01 caml-list:01 lazy:02 lazy:02 data:02 deallocate:03 On Monday 21 April 2008 14:11:51 Richard Jones wrote: > On Mon, Apr 21, 2008 at 02:27:36PM +0200, Berke Durak wrote: > > On Mon, Apr 21, 2008 at 1:17 PM, Jon Harrop wro= te: > > > Quad cores are already the norm. > > > > > > An *eight* core Dell Precision T7400 now costs only =A31,171. Our des= ktop > > > machines will be replaced with these eight core machines before the e= nd > > > of this year. > > > > Well it's worse than what I thought then. > > Your threaded code is going to look really stupid when you have NUMA > machines with dozens of cores. Why are we optimizing for a case (SMP) > which will only be around for a few years. Arguably SMP isn't even > around now ... the AMD machine on which I'm typing this is firmly NUMA > with a good 10% penalty for accessing memory owned by the other > socket. 10% is nothing compared to the orders of magnitude cost of message passing. > > A concurrent GC should be developed. But I think you can compete in > > some "niches" without a concurrent GC. > > Why should a concurrent GC be developed? Threaded code is a nightmare > to write & debug, and it's only convenient for lazy programmers who > can't be bothered to think in advance about how they want to share > data. OCaml supports fork, event channels & shared memory right now > (and has done for years) so there is no penalty to writing it > properly. Ten years ago that was: "Why should we use gargage collection? Garbage collectors are a nightmare= to=20 implement and debug and are only useful for lazy programmers who cannot be= =20 bothered to deallocate values themselves. C++ has reference counting right= =20 now and there is no penalty for using it properly." =2D-=20 Dr Jon D Harrop, Flying Frog Consultancy Ltd. http://www.ffconsultancy.com/products/?e