Date: Fri, 6 Feb 1998 18:39:14 +0000 (GMT) From: Terry Lambert <tlambert@primenet.com> To: jfieber@indiana.edu (John Fieber) Cc: calin@ibd.dbio.ro, freebsd-hackers@FreeBSD.ORG Subject: Re: Powering off the system/UPS Message-ID: <199802061839.LAA12897@usr01.primenet.com> In-Reply-To: <Pine.BSF.3.96.980206092018.9421F-100000@fallout.campusview.indiana.edu> from "John Fieber" at Feb 6, 98 09:25:53 am
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> > 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.
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