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=-1.1 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 2089 invoked from network); 8 Apr 2022 23:37:00 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 8 Apr 2022 23:37:00 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id C12209D6E8; Sat, 9 Apr 2022 09:36:56 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 5A6219D680; Sat, 9 Apr 2022 09:34:33 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="fseVJwj3"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id 7823E9D680; Sat, 9 Apr 2022 09:34:30 +1000 (AEST) Received: from mail-ua1-f48.google.com (mail-ua1-f48.google.com [209.85.222.48]) by minnie.tuhs.org (Postfix) with ESMTPS id DC0289D665 for ; Sat, 9 Apr 2022 09:34:29 +1000 (AEST) Received: by mail-ua1-f48.google.com with SMTP id t12so5074381uap.9 for ; Fri, 08 Apr 2022 16:34:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=0lPpC2R6uZQltBu6rjZKV/EiR33qNkb/eJ1HDPX4sVU=; b=fseVJwj3hGYrvEiLJlS43MdESaGTcf9IFRE2fMXUgncze/M5soY2H9Rp7Z80Bgskn4 UTAASWBZ1JBw1xKOhLcdD5pXCS5LI2kR9KOyR4TvX0QYxPwF2g2xGgDzC599259VKQNE i6WyjH81SPkXfustQXBj7Ui/VbqBMzjYGcFg2cNHxjR2uQL/y8np88kqKMS4RK8X4o0O eE83pnfoIbJRtWD9GncbkrA5UeTkZj5Q1QdaLJbfr31iLFxJupl9SWSnP+dbafJwlt9x 1x8wjaz4yyZLWlNym7WOHEC0L7+DQxy/SZTFT6t7mp4aJ3E43auzHbI68Jj53kUet28D GONA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=0lPpC2R6uZQltBu6rjZKV/EiR33qNkb/eJ1HDPX4sVU=; b=amU3tC8meCx2/PZtgttAX0SnsalmqroB5AgJ586BLC/Be0FvmycMkSJyO0BqNlZuKC /AylwT7NJmASe/Fqw1LTsoU3n/8X0L8JFkh4yjdrg8UB0WwS6bUvQkJE3VT7Gj++/jll /4MVarfxy1fvCFbbT91tux26FwQ7Siig08JOVgFcuNnC1JAhdQF6euWl01tJwBnn2baK wwyOaQKceCibiwpdQ/JJ2Q5vZvdQM+O6tmyNJWJLDaCQtO9KMSzDp8/grqdLtuDUxZno sKDtR3dcmNjUbaBVjRXujSw/vxCzhR8CvaZY6OVbvAitS72mQezCbfOr/4k4GfgPobye vmUA== X-Gm-Message-State: AOAM531DiFgW0GlVBkxBoe0BHXAniTeauXadx0Y0jW38OWg4c9+64FGB 4Qmdc4F7kS1XT9BD84BYTpqs7zrunTPFaOmSmoNk0Cj+ X-Google-Smtp-Source: ABdhPJwWhSj3n7aa61NwwXHTcRhiDkMMdijk11YyMcNo7VBlvcGJ4erGngSOegm6j4UfDrdQaMpod3yUInraBVJmtxY= X-Received: by 2002:ab0:6307:0:b0:35c:8290:55ff with SMTP id a7-20020ab06307000000b0035c829055ffmr5927481uap.122.1649460868689; Fri, 08 Apr 2022 16:34:28 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:ab0:2519:0:0:0:0:0 with HTTP; Fri, 8 Apr 2022 16:34:27 -0700 (PDT) In-Reply-To: References: <7wh774dtvi.fsf@junk.nocrew.org> <20220408152834.GE29186@mcvoy.com> From: Andrew Warkentin Date: Fri, 8 Apr 2022 17:34:27 -0600 Message-ID: To: The Unix Heritage Society mailing list Content-Type: text/plain; charset="UTF-8" Subject: Re: [TUHS] Interesting commentary on Unix from Multicians. X-BeenThere: tuhs@minnie.tuhs.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: The Unix Heritage Society mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" On 4/8/22, Greg A. Woods wrote: > > Single Level Storage is an awesome concept and removes so many ugly > hacks from algorithms that otherwise have to process data in files. > Doing data processing with read and write and pipes is effectively > working through a straw whereas SLS allows all (reasonably sized) data > to be presented in entirely complete randomly accessible arrays just by > attaching a "file" to a segment. Mmap() is a very poor replacement that > requires a great deal extra bookkeeping that's next to impossible to > hide from; and also there's the problem of the consistency semantics > being different between the I/O based filesystems and direct memory > mapping of their files, which Mmap() reveals, and which SLS eliminates > (by simply not having any I/O mechanism for files in the first place!). > I think it's useful to have both I/O and memory views for files. Things like commands that work equally well whether stdout is a disk file or something like a pipe wouldn't work so well in a system where disk files can only be accessed through a memory-like interface. However, I guess the I/O interface could just be implemented with library functions rather than real I/O syscalls for disk-like files. Maybe I could try doing something like that in my OS but I'm not completely sure if it would affect performance because it will be QNX-like, and reads and writes would probably require the VFS to act as an intermediary sometimes whereas that wouldn't be the case with I/O since reads and writes would otherwise map onto kernel message passing without any intermediary servers.