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To: Warner Losh <imp@bsdimp.com>
From: "Poul-Henning Kamp" <phk@phk.freebsd.dk>
In-Reply-To: Your message of "Fri, 19 Oct 2007 10:05:16 CST."
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Date: Fri, 19 Oct 2007 16:12:36 +0000
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Cc: Alexander@Leidinger.net, cnst@freebsd.org, arch@freebsd.org
Subject: Re: sensors fun.. 
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In message <20071019.100516.74722974.imp@bsdimp.com>, Warner Losh writes:

>> The kernel-userland interface should happen over a filedescriptor
>> (either device or unix-domain socket) so that whatever daemon we
>> park on the fd can just use select/poll/kqueue to wait for events.
>
>If we're going to have a stream of data from the kernel, is there any
>reason to invent another daemon for that?  We already have devd that
>deals with a number of disparate events from the kernel in a fairly
>generic way.

The kernel and userland sensors would result in two kinds of data,
measurements ("32°C") and events ("new sensor", "high temp")

devd should not see the measurements, but it might be a good idea
if it could see the events from all sensors (userland AND kernel).

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.