From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Original-To: caml-list@sympa.inria.fr Delivered-To: caml-list@sympa.inria.fr Received: from mail3-relais-sop.national.inria.fr (mail3-relais-sop.national.inria.fr [192.134.164.104]) by sympa.inria.fr (Postfix) with ESMTPS id B588D7F30A for ; Mon, 25 Feb 2013 16:45:52 +0100 (CET) Received-SPF: None (mail3-smtp-sop.national.inria.fr: no sender authenticity information available from domain of alain.frisch@lexifi.com) identity=pra; client-ip=193.252.23.214; receiver=mail3-smtp-sop.national.inria.fr; envelope-from="alain.frisch@lexifi.com"; x-sender="alain.frisch@lexifi.com"; x-conformance=sidf_compatible Received-SPF: None (mail3-smtp-sop.national.inria.fr: no sender authenticity information available from domain of alain.frisch@lexifi.com) identity=mailfrom; client-ip=193.252.23.214; receiver=mail3-smtp-sop.national.inria.fr; envelope-from="alain.frisch@lexifi.com"; x-sender="alain.frisch@lexifi.com"; x-conformance=sidf_compatible Received-SPF: None (mail3-smtp-sop.national.inria.fr: no sender authenticity information available from domain of postmaster@msa.smtpout.orange.fr) identity=helo; client-ip=193.252.23.214; receiver=mail3-smtp-sop.national.inria.fr; envelope-from="alain.frisch@lexifi.com"; x-sender="postmaster@msa.smtpout.orange.fr"; x-conformance=sidf_compatible X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AlwCAKGFK1HB/BfWYGdsb2JhbABFFoMivhyBGwMgKQMkgh8BAQU4QRALDgoJJQ8CRgYNAQcBARCIAwi+YI8OB4NAA5J8g0GBHYRYjXg X-IPAS-Result: AlwCAKGFK1HB/BfWYGdsb2JhbABFFoMivhyBGwMgKQMkgh8BAQU4QRALDgoJJQ8CRgYNAQcBARCIAwi+YI8OB4NAA5J8g0GBHYRYjXg X-IronPort-AV: E=Sophos;i="4.84,735,1355094000"; d="scan'208";a="3394053" Received: from msa05.smtpout.orange.fr (HELO msa.smtpout.orange.fr) ([193.252.23.214]) by mail3-smtp-sop.national.inria.fr with ESMTP; 25 Feb 2013 16:45:52 +0100 Received: from [192.168.1.120] ([92.151.93.34]) by mwinf5d18 with ME id 4flp1l00T0kVFFg03flpe2; Mon, 25 Feb 2013 16:45:51 +0100 Message-ID: <512B872B.60809@lexifi.com> Date: Mon, 25 Feb 2013 16:45:47 +0100 From: Alain Frisch Organization: LexiFi User-Agent: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:17.0) Gecko/20130107 Thunderbird/17.0.2 MIME-Version: 1.0 To: Gerd Stolpmann CC: Francois Berenger , caml-list@inria.fr References: <1361799073.2723.5@samsung> In-Reply-To: <1361799073.2723.5@samsung> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Validation-by: alain.frisch@lexifi.com Subject: Re: AW: [Caml-list] What is triggering a lot of GC work? On 02/25/2013 02:31 PM, Gerd Stolpmann wrote: > This can have counter-intuitive consequences. Yesterday I sped an > imperative program up by adding allocations! This is really an interesting scenario, thanks for sharing! Two other approaches to addressing the same performance issue could have been: 1. increase the size of the minor heap so that your array stays in it long enough; 2. try to reduce the number of other allocations. Did you try one of these approaches as well? (1 in particular is particularly easy to test.) Gabriel Scherer recently called the community to share representative "benchmarks", in order to help core developers target optimization efforts to where they are useful: http://gallium.inria.fr/~scherer/gagallium/we-need-a-representative-benchmark-suite/ Gabriel: except from LexiFi's contribution, did you get any code? Gerd: it would be great if you could share the code you mention above; is it an option? There are a number of optimizations which have been proposed (related to boxing of floats, compilation strategy for let-binding on tuples, etc), which could reduce significantly the allocation rate of some programs. In my experience, this reduction can be observed on real-sized programs, but it does not translate to noticeable speedups. It might be the case that your program would benefit from such optimizations. Having access to the code would be very useful! Alain