From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.5 required=5.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: from minnie.tuhs.org (minnie.tuhs.org [50.116.15.146]) by inbox.vuxu.org (Postfix) with ESMTP id CF36F24927 for ; Tue, 14 May 2024 00:01:55 +0200 (CEST) Received: from minnie.tuhs.org (localhost [IPv6:::1]) by minnie.tuhs.org (Postfix) with ESMTP id B7F4E43315; Tue, 14 May 2024 08:01:48 +1000 (AEST) Received: from mail-lf1-x131.google.com (mail-lf1-x131.google.com [IPv6:2a00:1450:4864:20::131]) by minnie.tuhs.org (Postfix) with ESMTPS id 50C384330B for ; Tue, 14 May 2024 08:01:40 +1000 (AEST) Received: by mail-lf1-x131.google.com with SMTP id 2adb3069b0e04-51ff65b1e14so5367032e87.2 for ; Mon, 13 May 2024 15:01:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1715637697; x=1716242497; darn=tuhs.org; h=content-transfer-encoding:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=JhmU/Ybh7gNo7GtogrivkuFTn2aueNYE7Hi1rHtI70k=; b=VCIMRZCLlbRqiDJh5PXgmuyLppXGuwB0JdDnujyfFP3M3h6vYIuMruz4g2XAoH81cj YVbz7aSvySQxM9XdWOhrNXvfJ5WV8DEDZzp8I+CpxSp8BUvsr7xE2sUQaHdhI0ExD9ch OaUWn7Agiubq/ZBrPKL/EMNLMQmoSr1f4Yh8b6MnJECDXH6bpKF/RD+IOn2/mcUFtfL2 8Cr6EehU/IU8qEat5A5/H0OagOZTA9KBhXLUnl8eL7Hg2ZiAKGYjZqoGbsTydzbgwNQr 8LhjqqC/pwWtCw8eOCKyusZFfoHyliXP3mxvtzgHjdJSplNhTFw2BxjAgYjj0bv/rIGA HZZw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1715637697; x=1716242497; h=content-transfer-encoding:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=JhmU/Ybh7gNo7GtogrivkuFTn2aueNYE7Hi1rHtI70k=; b=GXreG6/+5V5WjrQLnTWN8xSarT58iUIjEcMAExLkVAP2u2IKW84onIAOLkVziXQdVZ Fp5pUQ4Evt/ef/8OlhneQ4y30fcSCc7l5bBmFH/pH6VmJlhHNGFleLMD328v0KOiFF/K sshw26yyIz3yclQgiUIRIt4ArUK8JMfLtmn0B/LNSt4vRRUQe1aMgw+oLttXzfLm+9zL J9qG9fmM8rGkl7NGvvfTf6aeELWSJGaTONlTUT7kQWKxWIEBGWNr0iNY2WUwy4p01DvR cv3N7rF+HEsRetBsSVycP+FfNtQGpSx2BBSvmE0Ds/y7ouDwCS6ZiEq++Q1aJc3qaZFD Smeg== X-Gm-Message-State: AOJu0YxXhVyZ8c+vpOeSm/V2+8AVexHcH2y/Uu3yoRAciDspAmfpGHH2 JLrKp0/tt2UI2hPs0iEYHTfJ1a+oh131exLGkuOy5xAuuoCTVWdVHoPAzRQ6BArFohAcoh7YchR f42H0wmbAz1Ntp+QtmBHZW2wNGQl68A== X-Google-Smtp-Source: AGHT+IHT5QmUJX2633np4a8G7VR1HEp14YLXnXLKfVknLIU8fNSo/9SBTtxaVKnzNoazfEw93pMvwXPcx4Q17l+fXSs= X-Received: by 2002:ac2:5384:0:b0:51b:223f:ac47 with SMTP id 2adb3069b0e04-5220fd7adbbmr7044948e87.41.1715637696934; Mon, 13 May 2024 15:01:36 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Andrew Warkentin Date: Mon, 13 May 2024 16:01:24 -0600 Message-ID: To: The Eunuchs Historic Society Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Message-ID-Hash: 4IY7KVUXQMULN3XUCBQTHC6C5DRRHF6I X-Message-ID-Hash: 4IY7KVUXQMULN3XUCBQTHC6C5DRRHF6I X-MailFrom: andreww591@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 X-Mailman-Version: 3.3.6b1 Precedence: list Subject: [TUHS] Re: If forking is bad, how about buffering? List-Id: The Unix Heritage Society mailing list Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On Mon, May 13, 2024 at 7:42=E2=80=AFAM Douglas McIlroy wrote: > > > These precautions are mere fig leaves that conceal important special case= s. The underlying evil of buffered IO still lurks. The justification is tha= t it's necessary to match the characteristics of IO devices and to minimize= system-call overhead. The former necessity requires the attention of hard= ware designers, but the latter is in the hands of programmers. What can be = done to mitigate the pain of border-crossing into the kernel? L4 and its il= k have taken a whack. An even more radical approach might flow from the "wh= itepaper" at www.codevalley.com. > QNX copies messages directly between address spaces without any intermediary buffering, similarly to L4-like kernels. However, some of its libraries and servers do still use intermediary buffers.