From owner-freebsd-hackers Fri Feb 6 10:40:05 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id KAA29222 for hackers-outgoing; Fri, 6 Feb 1998 10:40:05 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from smtp02.primenet.com (smtp02.primenet.com [206.165.6.132]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id KAA29082 for ; Fri, 6 Feb 1998 10:39:29 -0800 (PST) (envelope-from tlambert@usr01.primenet.com) Received: (from daemon@localhost) by smtp02.primenet.com (8.8.8/8.8.8) id LAA26866; Fri, 6 Feb 1998 11:39:18 -0700 (MST) Received: from usr01.primenet.com(206.165.6.201) via SMTP by smtp02.primenet.com, id smtpd026848; Fri Feb 6 11:39:17 1998 Received: (from tlambert@localhost) by usr01.primenet.com (8.8.5/8.8.5) id LAA12897; Fri, 6 Feb 1998 11:39:14 -0700 (MST) From: Terry Lambert Message-Id: <199802061839.LAA12897@usr01.primenet.com> Subject: Re: Powering off the system/UPS To: jfieber@indiana.edu (John Fieber) Date: Fri, 6 Feb 1998 18:39:14 +0000 (GMT) Cc: calin@ibd.dbio.ro, freebsd-hackers@FreeBSD.ORG In-Reply-To: from "John Fieber" at Feb 6, 98 09:25:53 am X-Mailer: ELM [version 2.4 PL25] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG X-To-Unsubscribe: mail to majordomo@FreeBSD.org "unsubscribe hackers" > > I followed all your mail about how to patch the kernel. I seems that the > > solution that would satisfy (more or less) everybody would be an extra > > list for at_shutdown where both apm and ups drivers can insert callbacks. > > (the way I patched my system's kernel - haha). > > Maybe I missed it in the thread, but why it is a Good Thing to > put UPS support in the kernel as opposed to a purely user mode > daemon that monitors the UPS and does the Right Thing, like > shutdown(8), when things get to a critical state? Because the kernel knows about uncommitted write buffers, but the user space daemon does not, and the user space daemon might be fighting for a quantum with 1000 other processes, so it can't react before its too late to save your data. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.