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 mail4-relais-sop.national.inria.fr (mail4-relais-sop.national.inria.fr [192.134.164.105]) by yquem.inria.fr (Postfix) with ESMTP id 79ABFBBAF for ; Thu, 24 Sep 2009 12:41:45 +0200 (CEST) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: ApoEABjqukrZbprC/2dsb2JhbADWEoQbBQ X-IronPort-AV: E=Sophos;i="4.44,445,1249250400"; d="scan'208";a="47187036" Received: from grisu.bik-gmbh.de ([217.110.154.194]) by mail4-smtp-sop.national.inria.fr with ESMTP/TLS/DHE-RSA-AES256-SHA; 24 Sep 2009 12:41:10 +0200 Received: from [192.168.125.196] (abel.bik-gmbh.de [192.168.125.196]) by grisu.bik-gmbh.de (8.14.3/8.14.3) with ESMTP id n8OAeleW066184; Thu, 24 Sep 2009 12:40:47 +0200 (CEST) (envelope-from hars@bik-gmbh.de) Message-ID: <4ABB4CAF.8080505@bik-gmbh.de> Date: Thu, 24 Sep 2009 12:40:47 +0200 From: Florian Hars User-Agent: Thunderbird 2.0.0.23 (X11/20090817) MIME-Version: 1.0 To: Richard Jones Cc: Jon Harrop , caml-list@yquem.inria.fr, Philippe Wang Subject: Re: [Caml-list] OC4MC : OCaml for Multicore architectures References: <200909240105.18288.jon@ffconsultancy.com> <4d1b2df20909231701l2248f7f7w841b1d5ece9aa62e@mail.gmail.com> <200909240247.17560.jon@ffconsultancy.com> <20090924094943.GA14407@annexia.org> In-Reply-To: <20090924094943.GA14407@annexia.org> X-Enigmail-Version: 0.95.7 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Spam: no; 0.00; hars:01 hars:01 bik-gmbh:01 ocaml:01 0100,:01 2009:98 threads:01 wrote:01 caml-list:01 florian:03 florian:03 threaded:03 pattern:04 size:95 thu:05 Richard Jones schrieb: > On Thu, Sep 24, 2009 at 02:47:17AM +0100, Jon Harrop wrote: >> Wow! 2.6x faster on 2 cores is good. ;-) > > Isn't that impossible? Or is the multicore GC better than the single > threaded one? (Sorry if this is a stupid or obvious question) It might just happen that the size of the working set and memory access pattern of the application is just right so that you get a better interleaving of cache misses and thread execution if you run more than two threads on two cores. Hyperthreading might muddle things further. - Florian