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=-1.0 required=5.0 tests=MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 7861 invoked from network); 8 Feb 2021 18:21:44 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 8 Feb 2021 18:21:44 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 399679C279; Tue, 9 Feb 2021 04:21:42 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 480F69BA50; Tue, 9 Feb 2021 04:21:26 +1000 (AEST) Received: by minnie.tuhs.org (Postfix, from userid 112) id 3A15E9BA50; Tue, 9 Feb 2021 04:21:24 +1000 (AEST) Received: from mcvoy.com (mcvoy.com [192.169.23.250]) by minnie.tuhs.org (Postfix) with ESMTPS id AB5449BA42 for ; Tue, 9 Feb 2021 04:21:23 +1000 (AEST) Received: by mcvoy.com (Postfix, from userid 3546) id 281DA35E31A; Mon, 8 Feb 2021 10:21:23 -0800 (PST) Date: Mon, 8 Feb 2021 10:21:23 -0800 From: Larry McVoy To: Will Senn Message-ID: <20210208182123.GI13701@mcvoy.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Subject: Re: [TUHS] Macs and future unix derivatives X-BeenThere: tuhs@minnie.tuhs.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: The Unix Heritage Society mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: TUHS main list Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" On Mon, Feb 08, 2021 at 12:11:08PM -0600, Will Senn wrote: > And a bonus question, why, oh why, can't we have a contained kernel that > provides minimal functionality (dare I say microkernel), that is securable, > and layers above it that other stuff (everything else) can run on with > auditing and suchlike for traceability? I can answer the microkernel question I think. It's discipline. The only microkernel I ever liked was QNX and I liked it because it was a MICROkernel. The entire kernel easily fit in a 4K instruction cache. The only way that worked was discipline. There were 3 guys who could touch the kernel, one of them, Dan Hildebrandt, was sort of a friend of mine, we could, and did, have conversations about the benefits of a monokernel vs a microkernel. He agreed with me that QNX only worked because those 3 guys were really careful about what went into the kernel. There was none of this "Oh, I measured performance and it is only 1.5% slower now" nonsense, that's death by a hundred paper cuts. Instead, every change came with before and after cache miss counts under a benchmark. Stuff that increased the cache misses was heavily frowned upon. Most teams don't have that sort of discipline. They say they do, they think they do, but when marketing says we have to do $WHATEVER, it goes in.