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_INVALID,DKIM_SIGNED, MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 11784 invoked from network); 28 Nov 2022 13:25:41 -0000 Received: from minnie.tuhs.org (50.116.15.146) by inbox.vuxu.org with ESMTPUTF8; 28 Nov 2022 13:25:41 -0000 Received: from minnie.tuhs.org (localhost [IPv6:::1]) by minnie.tuhs.org (Postfix) with ESMTP id ACD2E41B9F; Mon, 28 Nov 2022 23:25:16 +1000 (AEST) Received: from ewsoutbound.kpnmail.nl (unknown [195.121.94.168]) by minnie.tuhs.org (Postfix) with ESMTPS id D9E3941B9B for ; Mon, 28 Nov 2022 23:25:04 +1000 (AEST) X-KPN-MessageId: f7978bd3-6f1f-11ed-be70-005056aba152 Received: from smtp.kpnmail.nl (unknown [10.31.155.37]) by ewsoutbound.so.kpn.org (Halon) with ESMTPS id f7978bd3-6f1f-11ed-be70-005056aba152; Mon, 28 Nov 2022 14:24:20 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=planet.nl; s=planet01; h=to:date:message-id:subject:mime-version:content-type:from; bh=83yDRbhXJJqkiyfX1aPOsBD/ZyVxnJ0fiphFSq44Or8=; b=z/9sif9Law3xAIkKyfy4MiUK6w2R7jnFZibH5d5yqye4go0C7ZiPVawkp8Vo38cnxcD7amsKCK7dy Bi/riB36o12e+npzw924Q3CXU8QMkwqBPhRbBjgGJQO6/E/Af1m+PIuX1xyFKgcxQJjibj/Hvh5gWD vFbm+4yKlDj26iww= X-KPN-MID: 33|pDrYEcWBvV1Bz5iklw8gBV6zeMEKZQAr/GlVqeL7ePDBZbassFBUTAC6Oz5MQ5Z LGzwEdxg5JtCaw9+5hzrnhpzliy+bQAA9n0wP3j0KJAo= X-KPN-VerifiedSender: Yes X-CMASSUN: 33|UQKryS9o3LXPxKTmwZFGrP1AYEHjb6l0M+kHvGlm4/CUXSluKVM+f44J8TB10oJ R4BElfigF/LjoUtSymgKpFQ== X-Originating-IP: 77.172.38.96 Received: from smtpclient.apple (77-172-38-96.fixed.kpn.net [77.172.38.96]) by smtp.kpnmail.nl (Halon) with ESMTPSA id 0aa07cf7-6f20-11ed-929c-005056ab1411; Mon, 28 Nov 2022 14:24:53 +0100 (CET) From: Paul Ruizendaal Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Mac OS X Mail 14.0 \(3654.120.0.1.13\)) Message-Id: <7C8CADAB-65AA-4841-AFA1-569A9651E56D@planet.nl> Date: Mon, 28 Nov 2022 14:24:52 +0100 To: The Eunuchs Hysterical Society X-Mailer: Apple Mail (2.3654.120.0.1.13) Message-ID-Hash: VHLTU72COOTBVO3UCNXLVMVNKFV3AIOT X-Message-ID-Hash: VHLTU72COOTBVO3UCNXLVMVNKFV3AIOT X-MailFrom: pnr@planet.nl X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; header-match-tuhs.tuhs.org-0; 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] Early multiprocessor Unix List-Id: The Unix Heritage Society mailing list Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: The discussion about the 3B2 triggered another question in my head: what = were the earliest multi-processor versions of Unix and how did they = relate? My current understanding is that the earliest one is a dual-CPU VAX = system with a modified 4BSD done at Purdue. This would have been late = 1981, early 1982. I think one CPU was acting as master and had exclusive = kernel access, the other CPU would only run user mode code. Then I understand that Keith Kelleman spent a lot of effort to make Unix = run on the 3B2 in a SMP setup, essentially going through the source and = finding all critical sections and surrounding those with spinlocks. This = would be around 1983, and became part of SVr3. I suppose that the = =E2=80=9Cspl()=E2=80=9D calls only protected critical sections that were = shared between the main thread and interrupt sequences, so that a manual = review was necessary to consider each kernel data structure for parallel = access issues in the case of 2 CPU=E2=80=99s. Any other notable work in this area prior to 1985? How was the SMP implementation in SVr3 judged back in its day? Paul=