From: Paul Ruizendaal <pnr@planet.nl>
To: The Eunuchs Hysterical Society <tuhs@tuhs.org>
Subject: [TUHS] Early multiprocessor Unix
Date: Mon, 28 Nov 2022 14:24:52 +0100 [thread overview]
Message-ID: <7C8CADAB-65AA-4841-AFA1-569A9651E56D@planet.nl> (raw)
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 “spl()” 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’s.
Any other notable work in this area prior to 1985?
How was the SMP implementation in SVr3 judged back in its day?
Paul
next reply other threads:[~2022-11-28 13:25 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-28 13:24 Paul Ruizendaal [this message]
2022-11-28 13:42 ` [TUHS] " Larry Stewart
2022-11-28 14:05 ` Clem Cole
2022-11-28 14:13 ` Clem Cole
2022-11-28 14:19 ` Warner Losh
2023-08-06 14:19 ` Warner Losh
2022-11-28 14:16 ` Warner Losh
2022-11-28 14:50 ` Clem Cole
2022-11-28 16:30 ` Paul Winalski
2022-11-28 16:49 ` Clem Cole
2023-08-06 14:12 ` Warner Losh
2022-11-28 16:52 ` Jonathan Gray
2022-11-29 9:39 ` Jonathan Gray
2022-11-29 15:54 ` [TUHS] First supercomputer UNIX: The Denelcor HEP (was Early multiprocessor Unix) Ron Natalie
2022-11-29 17:00 ` [TUHS] " Jon Steinhart
2022-11-29 20:53 ` steve jenkin
2023-08-05 23:00 ` [TUHS] Re: Early multiprocessor Unix scj
2023-08-06 0:54 ` Larry McVoy
2023-08-06 6:52 ` Paul Ruizendaal
2023-08-06 9:28 ` Ronald Natalie
2023-08-06 9:57 ` Ralph Corderoy
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