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, HTML_FONT_LOW_CONTRAST,HTML_MESSAGE,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 16901 invoked from network); 28 Nov 2022 14:07:39 -0000 Received: from minnie.tuhs.org (50.116.15.146) by inbox.vuxu.org with ESMTPUTF8; 28 Nov 2022 14:07:39 -0000 Received: from minnie.tuhs.org (localhost [IPv6:::1]) by minnie.tuhs.org (Postfix) with ESMTP id 216EB41BA3; Tue, 29 Nov 2022 00:07:32 +1000 (AEST) Received: from mail-il1-f169.google.com (mail-il1-f169.google.com [209.85.166.169]) by minnie.tuhs.org (Postfix) with ESMTPS id 7C86A40F36 for ; Tue, 29 Nov 2022 00:07:26 +1000 (AEST) Received: by mail-il1-f169.google.com with SMTP id bp12so5033692ilb.9 for ; Mon, 28 Nov 2022 06:07:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ccc.com; s=google; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=CB7Ohcr3PaTBJvpYkOM79fSp4MBzTZh7AB5thujvPPY=; b=Cufxuriab52QGzgX2zkcv3OGX04/wC6B1ZCimN6rlHxkaXn2B69l6QfPhowctNH72Y GtnRJQVv3+6MNxABMARPiSbNsY+yDuZpscAAL2FqsaDpcG6Pgz/BYTYbJ4feGnA9M1Pq lr03uT9n4H8jQnCoJvWGZ1niPOvj1RfOa0Vr4= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc: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=CB7Ohcr3PaTBJvpYkOM79fSp4MBzTZh7AB5thujvPPY=; b=j6ZMY1EneRS94ZtAphVRN/ovfSpEEF9pLhFw+YZA708C+YQtVh+I28/Wia9Ec4VHv/ 1LjiqC6+0JQRRlHxpt99GrXcqmnOgrDt7tOH2CVdQU7Dluhz6Aag3sZxsB3zmdd+vWjQ 3Ymq7LVuCFJpXX4eRdIEroxAFqjVPtlOjiRk5EZpNZNnLJlhOm/UzNzouHrHFnDCd/CG aRQNY/lXsVuLTBC8JS4JZ2lJB0d25Fw1NzhoKz+gwQXK5D5LWwuAyMEwix9b3MKtyIeA 0fA7d93gZ+tGkn5r01b0PUTlrshDj7fucp9IBwZe0pNZyDacAS3QJwFPrTsVvVT7+Ayk ERIg== X-Gm-Message-State: ANoB5plV/zXFVAzPJNtU5rQct8c6uaYGhvUsJaHb9JWI4fxjANTqsiN+ je//v2Bj44odWisfUJcUZiGLDKsbAwwr2G4xXEWrIWAUTqm8TA== X-Google-Smtp-Source: AA0mqf7OXlKWjS4jLV1BcMzsNdSmI9tTO9tjS5mkz7kTKCdT2EgZSllhVXYNzwzb30aOIfh3rNBfZtvuJe2Ti4+DA8w= X-Received: by 2002:a05:6e02:108:b0:302:b8e6:deb7 with SMTP id t8-20020a056e02010800b00302b8e6deb7mr15563212ilm.247.1669644385479; Mon, 28 Nov 2022 06:06:25 -0800 (PST) MIME-Version: 1.0 References: <7C8CADAB-65AA-4841-AFA1-569A9651E56D@planet.nl> In-Reply-To: <7C8CADAB-65AA-4841-AFA1-569A9651E56D@planet.nl> From: Clem Cole Date: Mon, 28 Nov 2022 09:05:57 -0500 Message-ID: To: Paul Ruizendaal Content-Type: multipart/alternative; boundary="0000000000007f897905ee88606e" Message-ID-Hash: A7GXN6M6YY4GIFGTHJKP26SNIYEULYIO X-Message-ID-Hash: A7GXN6M6YY4GIFGTHJKP26SNIYEULYIO X-MailFrom: clemc@ccc.com 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 CC: The Eunuchs Hysterical Society X-Mailman-Version: 3.3.6b1 Precedence: list Subject: [TUHS] Re: 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: --0000000000007f897905ee88606e Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable As far as I know, the first non-commercial work was done at the Naval Post Grad school with V6. I have never seen the code for it, only a paper, so I don't know too much about it to comment. A few years later (1980), Goble's work became the Purdue Vax [ https://en.wikipedia.org/wiki/George_H._Goble] - which used a master-slave configuration. He spliced a second 780 CPU onto the SMB and, with some interesting work, allowed the second CPU to run user code. This was extremely effective for their usage case -- timesharing of students. If we don't have the code on TUHS, we should probably dig it up, as it was widely distributed. The other thing he did was splice an 11/40 onto the UBA of the same system for debugging - which was a pretty cool hack. He found a couple of interesting BSD kernel issues, including a famous CVE using his real-time monitor -- there is a USENIX paper on that tool that is work checking out. The first commercial MP Unix was the Masscomp MC500/MP, which was originally developed as Goble-style Master/Slave and released in RTU 2.0. A year later, with RTU 3.0 and the release of the MC5000 family, it was fully SMP. After that, several SMP UNIX started to appear. Each uses its own lock scheme. If you are interested, I recommend getting a copy of Schimmel's book: 'Unix on Modern Processors' which discusses many (most) of the challenges. =E1=90=A7 On Mon, Nov 28, 2022 at 8:25 AM Paul Ruizendaal wrote: > The discussion about the 3B2 triggered another question in my head: what > were the earliest multi-processor versions of Unix and how did they relat= e? > > My current understanding is that the earliest one is a dual-CPU VAX syste= m > with a modified 4BSD done at Purdue. This would have been late 1981, earl= y > 1982. I think one CPU was acting as master and had exclusive kernel acces= s, > 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 cas= e > 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 --0000000000007f897905ee88606e Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
As far as I know, the first non-commercial=C2=A0work wa= s done at the Naval Post Grad school with V6.=C2=A0 I have never seen the c= ode for it,=C2=A0only a paper, so I don't know too much about it to com= ment.

A few years later (1980), Goble's work becam= e the Purdue Vax [https://en.wikipedia.org/wiki/George_H._Goble] - which used a master-s= lave configuration. He spliced a second 780 CPU onto the SMB and, with some= interesting work, allowed the second CPU to run user code.=C2=A0 This was = extremely effective for their usage case -- timesharing of students.=C2=A0 = If we don't have the code on TUHS, we should probably=C2=A0dig it up, a= s it was widely distributed. The other thing he did was splice an 11/40 ont= o the UBA of the same system for debugging - which was a pretty cool hack.= =C2=A0 He found a couple of interesting BSD kernel issues, including a famo= us CVE using his real-time monitor -- there is a USENIX paper on that tool = that is work checking out.

The first commercial=C2=A0M= P Unix was the Masscomp MC500/MP, which was originally developed as Goble-s= tyle Master/Slave and released in RTU 2.0.=C2=A0 A year later, with RTU 3.0= and the release of the MC5000 family, it was fully SMP.

=
After that, several SMP UNIX started to appear.=C2=A0 =C2=A0Each uses it= s own lock scheme.=C2=A0 =C2=A0If you are interested, I recommend getting a= copy of Schimmel's book: 'Unix on Modern Processors' which dis= cusses many (most) of the challenges.


=
3D""=E1=90=A7

On Mon, Nov 28, 2022 at 8:25 AM Paul Ruizendaal <pnr@planet.nl> wrote:
The discussion about the 3B2 trig= gered another question in my head: what were the earliest multi-processor v= ersions 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 ru= n on the 3B2 in a SMP setup, essentially going through the source and findi= ng all critical sections and surrounding those with spinlocks. This would b= e 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 t= he main thread and interrupt sequences, so that a manual review was necessa= ry 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
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