From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=5.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FROM,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 9958 invoked from network); 14 Mar 2023 03:06:23 -0000 Received: from minnie.tuhs.org (2600:3c01:e000:146::1) by inbox.vuxu.org with ESMTPUTF8; 14 Mar 2023 03:06:23 -0000 Received: from minnie.tuhs.org (localhost [IPv6:::1]) by minnie.tuhs.org (Postfix) with ESMTP id 1367041352; Tue, 14 Mar 2023 13:06:19 +1000 (AEST) Received: from mail-ot1-x330.google.com (mail-ot1-x330.google.com [IPv6:2607:f8b0:4864:20::330]) by minnie.tuhs.org (Postfix) with ESMTPS id B6BAD412C5 for ; Tue, 14 Mar 2023 13:06:10 +1000 (AEST) Received: by mail-ot1-x330.google.com with SMTP id q11-20020a056830440b00b00693c1a62101so7864247otv.0 for ; Mon, 13 Mar 2023 20:06:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1678763170; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=b4SHTWkoAAYBQ57/+BEBeNu6uWZMXyIj+D08PCPGaFk=; b=HRjfPxG9vGcNjCV4+9jD217no6RFLQKG7SLnWNGAq2K2MSf850yHOuMlbbMCPDbmSi npbqXs/ffcRW0cFGsmO1frkxcc4EdAEx41C7+C2O/TMm9hX+EAl99I9FxjbfyXwJR1XC vLp+VijDOMR5RmhoLVoMcsFyl8sNL/9M+EBrB7xC0jC/RnO7uZcZR+y5d34Fjk7LNmxo QVr5Oz0ujXLMNJvrjEM++S5jx5YWWgA8QLof2MOCBRpe5RLL4+Fe5xDQbIgsLzVH7dL1 3qK0IsQl8CzFX1el6ukLCK7b+/cPmjkKtQ+E6GpPAeESiC1Nxo+tUpMSCzO64zngWFav EmIg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678763170; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=b4SHTWkoAAYBQ57/+BEBeNu6uWZMXyIj+D08PCPGaFk=; b=q8iTUbhQsfL0A4un+46ty+xnRizXv8AOp4NKp/c4V5ITzqisO9uchf5Y0Em5yIVXKK sWIySQqsC1pU9Gljj3KeiS/rPdmApkDUXTVKutlPDMi/gLrfIYcc9T/BnUD9SYFTA/OS RrX/XC9CTxsTQhZrvvfl2H6s/n8/vYUT6MzF6Rgtaa9XBEyNyyQOrisZpGt5vInE7CRg pB+S1XKy6KGb9ukoaXmP8dYQuF84AtuoJ3IJ+vZsfkR2NPQ8nTOkrjoHUuCu8fUzfWYh VLWoAr77regXMr8xH89BFUPogFbqHKxC4hV7Df788GiIk+LvntPUvBHo5Ux33IL6APti rNYA== X-Gm-Message-State: AO0yUKXBcGWH5pMlhNXMtECkDZE8wVSW3MGUtgfBTZ1M5OWiZng84CQK Ih6po/PYnBefYhAYvoEHuUH+wOZgyOFvLA== X-Google-Smtp-Source: AK7set+V+EhJFGl4P1GkV3YhUE3xJ2dYvFt2tI6DDDRVDNgj72dUieNiccWNHerWLFy8TrCf5OJbgQ== X-Received: by 2002:a9d:7194:0:b0:690:d3d4:b7d5 with SMTP id o20-20020a9d7194000000b00690d3d4b7d5mr17479259otj.11.1678763169881; Mon, 13 Mar 2023 20:06:09 -0700 (PDT) Received: from illithid (ip68-12-97-90.ok.ok.cox.net. [68.12.97.90]) by smtp.gmail.com with ESMTPSA id e11-20020a9d490b000000b006884c42a38asm703756otf.41.2023.03.13.20.06.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 13 Mar 2023 20:06:09 -0700 (PDT) Date: Mon, 13 Mar 2023 22:06:07 -0500 From: "G. Branden Robinson" To: Theodore Ts'o Message-ID: <20230314030607.ermpipkakhassitv@illithid> References: <20230310113708.AD55518C080@mercury.lcs.mit.edu> <20230314024923.GN860405@mit.edu> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="cci2yllolvlwosr7" Content-Disposition: inline In-Reply-To: <20230314024923.GN860405@mit.edu> Message-ID-Hash: S5KKFTE7KYITXJG6LOU5C2SCDQRZNF4G X-Message-ID-Hash: S5KKFTE7KYITXJG6LOU5C2SCDQRZNF4G X-MailFrom: g.branden.robinson@gmail.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: Alejandro Colomar , TUHS X-Mailman-Version: 3.3.6b1 Precedence: list Subject: [TUHS] Re: [TUHS]: C dialects (was: I can't drive 55: "GOTO considered harmful" 55th anniversary) List-Id: The Unix Heritage Society mailing list Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: --cci2yllolvlwosr7 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable At 2023-03-13T22:49:23-0400, Theodore Ts'o wrote: > As an OS engineer, I deeply despise these optimization tricks, since I > personally I care about correctness and not corrupting user data far > more than I care about execution speed ---- especially when the parts > of the kernel I work on tend not to be CPU bound in the first place. Alex has heard me say this before. In the U.S., civilian air traffic controllers have a maxim. Safe, orderly, efficient.[1] You meet these criteria in order from left to right, and you satisfy one completely, or to some accepted, documented, and well-known standard measure, before you move on to the next. The obvious reason for this is that when aircraft meet each other at cruise altitudes, many people die. I haven't yet settled on a counterpart for software engineering that I like, but the best stab at it I've come up with is this. Comprehensible, correct, efficient. Incomprehensible code is useless.[2][3] Even code that is proven correct by formal methods is fragile if human maintainers are defeated by its esoteric expression.[4] (And formal verification can't save you =66rom incorrect specification in the first place.) Richard Feynman once said something along the lines of, if there is any phenomenon in physics that he can't successfully explain to an audience of freshmen, then we don't really understand it yet. We use subtle, complex tools to solve problems only when we haven't worked out ways to overcome them with simple, straightforward ones. Before we surrender to the excuse of irreducible complexity we must have valid, verifiable, peer-reproducible evidence that we've reduced the complexity as far as known methods will allow. But I'm junior to most of the grognards are on this list, so I'm half-expecting the Joe Pesci opening statement from _My Cousin Vinny_... Regards, Branden [1] https://www.avweb.com/features/say-again-8air-traffic-chaos/ [2] Literally useless, especially once that something that "just works" is ported to a new context. "The real problem is that we didn't understand what was going on either." https://www.bell-labs.com/usr/dmr/www/odd.html [3] Except for constructing streams of self-lauding horse puckey before promotion committees comprised of people who themselves attained, and will further advance, their status predicated on the audacity of their horse puckey. [4] And once something's _that_ solid, it may be time to consider etching it in silicon rather than primary or secondary storage. --cci2yllolvlwosr7 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEh3PWHWjjDgcrENwa0Z6cfXEmbc4FAmQP5JcACgkQ0Z6cfXEm bc7meRAAo9y3R2hAduGQY3NQAx40D7cj2cIY/kBVrcPr0WqtdF9lheYSWz4BHxJB PJTVW1d//WQ+ItZLdsC4qUc0lntoDkHFeKCkNJVZkjsYtvjFr6BdydzDNKCu3w++ dOffih8cMqw6T40amtmOyZu2Sn9FUy47gx+po6jHCBLBaCOQV1kM2kI6xXPobmBY 9kg6KfoJPYMXteIDsrK05iq1kNjCKt2q+Bb8vhQA/WIsVu+pKi/Ax/GblO8CRyLE EFM8kgD+tdF88/o5rFkGPC5ocSAsP6dxGmEw/2JbDBUC6XcLyGDjtxpET3fhtV+e uwreY+vvU8+k3kb/fqdG+WS5WqSoVsq5ujjqeZIqS7JpWggaX++4F42FotH8nV6w y7p5/F4soUM0KIfSEDkMGItL8EMdprMpOMO0tsil9JXl5ehBRW44T13+bRA3+aot xd2mtEK3X+mWdrs/G3zk9U94+0afb2qPeI2gYlQS1vfjB9rSrWlBTLl1AMw6qOEx 8YTRUhgRUeG9n9++vzu2aAVBPG2LECkNpEpbGvzJu12ypiBbL01hAbpyUK6TyDzz LzBx+ORi8yycJkpRsnR0nMy66lSKIzZuyctgbm6HN4D5JRm2a6h2x7DF0x/Pd0V6 r8Tu5fk/qBaKngUJNxxM095ZE53roS0JtiFhWS8D2117iPSiJPs= =T6Z1 -----END PGP SIGNATURE----- --cci2yllolvlwosr7--