From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: tuhs-bounces@minnie.tuhs.org X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.4 required=5.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE, T_DKIM_INVALID autolearn=ham autolearn_force=no version=3.4.1 Received: from minnie.tuhs.org (minnie.tuhs.org [45.79.103.53]) by inbox.vuxu.org (OpenSMTPD) with ESMTP id 513a48af for ; Thu, 28 Jun 2018 16:45:54 +0000 (UTC) Received: by minnie.tuhs.org (Postfix, from userid 112) id 14BD6A1853; Fri, 29 Jun 2018 02:45:53 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id E3B24A1816; Fri, 29 Jun 2018 02:45:44 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b=LgV/oG8X; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id 9DD74A1816; Fri, 29 Jun 2018 02:45:43 +1000 (AEST) Received: from mail-lj1-f169.google.com (mail-lj1-f169.google.com [209.85.208.169]) by minnie.tuhs.org (Postfix) with ESMTPS id 8115B9EDF1 for ; Fri, 29 Jun 2018 02:45:41 +1000 (AEST) Received: by mail-lj1-f169.google.com with SMTP id c11-v6so5043697lja.4 for ; Thu, 28 Jun 2018 09:45:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=7vr3OGw5MovZcogUae+RWgCefbMCWG3+tPWjv6bTUN4=; b=LgV/oG8XnA6ZqaD4wv34yhJeN+k1/flSF2R0bpZhGKijYRTX68KF0wDp7V5SPgsbkP NZaUBBdu9+GSBDgfYLXpvudgE6ta2PNnkgS4oeveX9qo6tSlzQgEek6+KuYxOaj+OBa9 8KiXt4F5k/Xe45NtUDJdECRaMRKXbf38/ylxLJ8OFl2OqqlXuJaLjeX+KQc8r01DYV4z 3cj+zPWr6cpgdP10oK4xBDanYViLjdiioukKj++msDETqUBty9cgYLHNUtgLMtPpElWn G8RJAbOZr4W6UWa0O0J2PYBAQaFxj3eVj+IVvuYuKXcuYUAERsEJY35aoYI1Uczsc3pr 9ruA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=7vr3OGw5MovZcogUae+RWgCefbMCWG3+tPWjv6bTUN4=; b=AgmHJjA5kwrKgO+PQjomBeUFgIluAr8xVfZf8nD3fW2GkoofkCBFkLkAL6zZ7pmxWx nmJwBOGUrk8gbmMSHST2RZFncR53tdFCH/MoyFTQ1LLlBpuKynYSW7TYxCTw2BlsyBYH IJ1gM/wSlQqRaBIT+utAJOyowYRTxenw0g+gLNT1DPjdfbEMHExct/2fjxuN/LAWm46D 3sDrnY2XlZ5rvVlXQjuZ84zdmCy8KoJXi+F5hY+IKKHfMyznYI3ECrmGBHreff64lq2m KAIszwIwC/AbOQHeCn5Q3j/B9Vsn645iEXGq5BSI/TOa/xS1/+Es7dB285ebuenLgEkV lnKw== X-Gm-Message-State: APt69E0J+xIuMrHiASXKHrw9O0bsYhxw5bbFo2W5WCoUDZt2ARqULq+S 1a4b6qGLQBmSOe1T3lKRuwf4oI7F1Ag62f3ec04= X-Google-Smtp-Source: AAOMgpdei7S3YDUOtUCXBA/h23ht6Rk8hyM1reeU3Gbnr3FfvNedxuIZCUknljCq+JHJpQPzJ3S2DqZBzJl1n/PEl1s= X-Received: by 2002:a2e:3a0e:: with SMTP id h14-v6mr5622674lja.20.1530204339863; Thu, 28 Jun 2018 09:45:39 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a2e:5c81:0:0:0:0:0 with HTTP; Thu, 28 Jun 2018 09:45:39 -0700 (PDT) In-Reply-To: <20180628141538.GB663@thunk.org> References: <81277CC3-3C4A-49B8-8720-CFAD22BB28F8@bitblocks.com> <20180628141538.GB663@thunk.org> From: Paul Winalski Date: Thu, 28 Jun 2018 12:45:39 -0400 Message-ID: To: "Theodore Y. Ts'o" Content-Type: text/plain; charset="UTF-8" Subject: Re: [TUHS] PDP-11 legacy, C, and modern architectures X-BeenThere: tuhs@minnie.tuhs.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: The Unix Heritage Society mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: tuhs@minnie.tuhs.org Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" On 6/28/18, Theodore Y. Ts'o wrote: > > It's the same mistake > Chisnall made when he assrted the parallel programming a myth that > humans writing parallel programs was "hard", and "all you needed" was > the right language. I''ve heard the "all you need is the right language" solution to the parallel processing development problem since I joined DEC in 1980. Here we are in 2018 and nobody's found that "right language" yet. Parallel programming *is* hard for humans. Very few people can cope with it, or with the nasty bugs that crop up when you get it wrong. > The problem is that not all people are interested in solving problems > which are amenable to embarassingly parallel algorithms. Most interesting problems in fact are not embarrassingly parallel. They tend to have data interdependencies. There have been some advancements in software development tools to make parallel programming easier. Modern compilers are getting pretty good at loop analysis to discover opportunities for parallel execution and vectorization in sequentially-written code. -Paul W.