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 25079 invoked from network); 20 Dec 2022 23:20:10 -0000 Received: from minnie.tuhs.org (50.116.15.146) by inbox.vuxu.org with ESMTPUTF8; 20 Dec 2022 23:20:10 -0000 Received: from minnie.tuhs.org (localhost [IPv6:::1]) by minnie.tuhs.org (Postfix) with ESMTP id 4B76C423E6; Wed, 21 Dec 2022 09:19:36 +1000 (AEST) Received: from mail-qt1-f181.google.com (mail-qt1-f181.google.com [209.85.160.181]) by minnie.tuhs.org (Postfix) with ESMTPS id 3CFA3423D6 for ; Wed, 21 Dec 2022 09:19:31 +1000 (AEST) Received: by mail-qt1-f181.google.com with SMTP id s9so12446677qtx.6 for ; Tue, 20 Dec 2022 15:19:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=iitbombay-org.20210112.gappssmtp.com; s=20210112; h=to:references:message-id:content-transfer-encoding:cc:date :in-reply-to:from:subject:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=kGegikavKoNaLi5mR+D4tZAnF/eS2Mi8j2HIBrU6iKI=; b=qVfBSAjLXbqx1Yyl1JAH2tYpndX1HUuLgBfE4AC+pgooNNH4BaLQVDV/gdGnxPlZmc yQBaYJejXXyx7svV1jLeu7zRjAIpzk8Tt+A95YZCrHF8BLmvW+CSY3weq/XF+spoWN+Q ruRT98Qqkj/Ui2gaFDnhebNVDU9pZ6yLtKuwo9iWM8cvStM0FglX/fy+eI9WNmhmjWf4 m9uCmM0fMGUhNOkwPSBvyww3AYKmgiPgq693q1zT417EQNoRf31RM2usOYZxPCCdx+uh J/WQpbKpHkiqTGXEFKE+638TwULT+VHjdN2j4HMaCE4STOt46Txevx2uL2YNOPsgY4Au pgSA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=to:references:message-id:content-transfer-encoding:cc:date :in-reply-to:from:subject:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=kGegikavKoNaLi5mR+D4tZAnF/eS2Mi8j2HIBrU6iKI=; b=GCYuDFLdTxb1ZMaMR8DXBdvBZxd0WFnhl+4Xxz1MWeYY1YZgkqtidr5nIVKk32pG6a SzQZBYc6aHxGJx0LkUo3vk5b6NJUiYo3NJ9MIsmLCJNdT0E9wD/htN3/Qo38JQf8BQRY nyy+X3S4B8zZq8inVG5H0lWTi6RFN+RlOUIHNRBmUgiTGvPAa099UAblFMChd81J9koF 80g6LlXtQSF0gqOeTIFEy9o+ISw7lA5bE+L9yZZbBCD2Vdm7w0l6QEE8LpEC6NdqBSQq k5cCjbT7zCSYb79z33DxuzfuMKU9ysQ3aBMD6olReKMWEFn7ss0sGkszOWpFg2bYMFaJ tWrg== X-Gm-Message-State: ANoB5plcQBcULqtK8F0JbAqqFNPgS1iG4Wnph2f70732DtGmU7mG2KAK BkhTPhwfjFV5PtcdX3vB21IPIXnMBa2lW2H4 X-Google-Smtp-Source: AA0mqf6+515YBMp0XCQiIPW1TP+PAEcMKGU02UnhILKhWFqY53TKQDb3bviyn2+00x8aXO5gt8tzaQ== X-Received: by 2002:a05:622a:1353:b0:3a8:3028:ce4a with SMTP id w19-20020a05622a135300b003a83028ce4amr41751281qtk.53.1671578310431; Tue, 20 Dec 2022 15:18:30 -0800 (PST) Received: from smtpclient.apple (107-215-223-229.lightspeed.sntcca.sbcglobal.net. [107.215.223.229]) by smtp.gmail.com with ESMTPSA id w4-20020a05620a424400b006e54251993esm9854156qko.97.2022.12.20.15.18.29 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 20 Dec 2022 15:18:30 -0800 (PST) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3731.300.101.1.3\)) From: Bakul Shah In-Reply-To: <20221220222531.3DC0818C079@mercury.lcs.mit.edu> Date: Tue, 20 Dec 2022 15:18:18 -0800 Content-Transfer-Encoding: 7bit Message-Id: References: <20221220222531.3DC0818C079@mercury.lcs.mit.edu> To: Noel Chiappa X-Mailer: Apple Mail (2.3731.300.101.1.3) Message-ID-Hash: C7OFBAEMQ57TWRD5RYTOYB6GBOHYUWUA X-Message-ID-Hash: C7OFBAEMQ57TWRD5RYTOYB6GBOHYUWUA X-MailFrom: bakul@iitbombay.org 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: tuhs@tuhs.org X-Mailman-Version: 3.3.6b1 Precedence: list Subject: [TUHS] Re: UNIX on (not quite bare) System/370 List-Id: The Unix Heritage Society mailing list Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: > On Dec 20, 2022, at 2:25 PM, Noel Chiappa wrote: > >> From: Bakul Shah > >> Is there a publicly available description of Reiser's VM system? I >> found "A Unix operating system for the DEC VAX 11/780 Computer" by >> London & Reiser which includes a long paragraph on VM (included below) > > That para is basically all about the VAX paging hardware; it doesn't say > anything about how that (any :-) Unix actually uses it. You are right! Mea culpa. There is a further para: Like the UNIX system for the PDP-11, the current implementation for the VAX-11/780 maintains each process in contiguous physical memory and swaps processes to disk when there is not enough physical memory to contain them all. Reducing external memory fragmentation to zero by utilizing the VAX- 11/780 memory mapping hardware for scatter loading is high on the list of things to do in the second imple- mentation pass. To simplify kernel memory allocation, the size of the user-segment memory map is an assembly parameter which currently allows three pages of page table or 192K bytes total for text, data, and stack. This also deserves to be rewritten, both to allow varying process size, and to allow processes larger than physical memory through demand paging. Dynamic page table size would mean dynamic u area size if the page table remained part of the u area. This seems like a minimal "bring up" port of V7. Later they must have implemented demand paging?