From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (from majordomo@localhost) by pauillac.inria.fr (8.7.6/8.7.3) id TAA26556; Sun, 24 Nov 2002 19:13:02 +0100 (MET) X-Authentication-Warning: pauillac.inria.fr: majordomo set sender to owner-caml-list@pauillac.inria.fr using -f Received: from nez-perce.inria.fr (nez-perce.inria.fr [192.93.2.78]) by pauillac.inria.fr (8.7.6/8.7.3) with ESMTP id TAA26547 for ; Sun, 24 Nov 2002 19:13:01 +0100 (MET) Received: from mallaury.noc.nerim.net (mallaury.noc.nerim.net [62.4.17.82]) by nez-perce.inria.fr (8.11.1/8.11.1) with ESMTP id gAOID0119661 for ; Sun, 24 Nov 2002 19:13:00 +0100 (MET) Received: from hector.lesours (lesours.starynkevitch.net [80.65.224.217]) by mallaury.noc.nerim.net (Postfix) with ESMTP id 4ADFF62E35; Sun, 24 Nov 2002 19:12:58 +0100 (CET) Received: from basile by hector.lesours with local (Exim 3.36 #1 (Debian)) id 18G1Fb-0008UT-00; Sun, 24 Nov 2002 19:12:59 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Message-ID: <15841.5801.232036.876630@hector.lesours> Date: Sun, 24 Nov 2002 19:12:57 +0100 To: Chris Hecker Cc: Sven Luther , Lauri Alanko , caml-list@inria.fr Subject: Re: [Caml-list] Why systhreads? In-Reply-To: <4.3.2.7.2.20021124093204.039731b8@localhost> References: <20021123090806.GA633@la.iki.fi> <4.3.2.7.2.20021124093204.039731b8@localhost> X-Mailer: VM 7.07 under Emacs 21.2.2 From: Basile STARYNKEVITCH Sender: owner-caml-list@pauillac.inria.fr Precedence: bulk >>>>> "Chris" == Chris Hecker writes: Chris> On a related note, now that the first CPUs with Chris> HyperThreading are shipping, is there any plan to Chris> multithread the GC so caml programs can take advantage of Chris> HT? I can understand why it was not a high priority to Chris> support real threads for multiprocessor machines when that Chris> was the only way to get parallelism with threads, but once Chris> HT is ubiquitous, it has the potential to make it worth the Chris> trouble to thread a regular application to increase Chris> performance. I don't think this is a high priority now, Chris> because there's 0% penetration of HT right now, but Chris> hopefully there's some plan for the future. I would suppose that HyperThreading chips can already successfully being used on Linux (I was told, IIRC, that such chips gives 2 cpu when asked thru /proc/cpuinfo). So, I would suppose that they can take advantage of native threads on Ocaml already. Chris> I guess the question is, is a multithreaded GC an open Chris> research problem, or is there a known good solution and it Chris> just hasn't gotten to the top of the priority list yet? I have a question to the Ocaml team : Could they explain what is the current (and perhaps near future) status of multithreading in Ocaml, notably with respect to garbage collection? I thought that the current GC in Ocaml (3.06) is already multithread-capable, at least because each thread has his own birth region and can do minor garbage collections independently of other threads, so threads have to synchronize only on major (ie full) garbage collections. Is my assumption correct? I just had a glance into ocaml/byterun/minor_gc.c and did not found any thread-local variables there... Also, ocaml/otherlibs/systhreads/posix.c mentions /* The global mutex used to ensure that at most one thread is running Caml code */ What is (with ocamlopt -thread on x86/linux) the use of multithreading in Ocaml? I really thought that it was really (in practical terms) biprocessor support, not only some limited kind of (throwable once only) continuations? Regards. -- Basile STARYNKEVITCH http://starynkevitch.net/Basile/ email: basilestarynkevitchnet alias: basiletunesorg 8, rue de la Faïencerie, 92340 Bourg La Reine, France ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners