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From: danzig@ucbarpa.berkeley.edu
Newsgroups: comp.sys.sun
Subject: Re: Reading Sun 3 timer register within Kernel device driver
Keywords: Hardware
Message-ID: <3857@brazos.Rice.edu>
Date: 8 Dec 89 07:12:46 GMT
Sender: root@rice.edu
Organization: Sun-Spots
Lines: 20
Approved: Sun-Spots@rice.edu
X-Refs:  Original: v8n207, Replies: v8n215
X-Sun-Spots-Digest: Volume 8, Issue 220, message 7 of 19

In article <3295@brazos.Rice.edu> you write:
>X-Sun-Spots-Digest: Volume 8, Issue 207, message 12 of 16
>
>I have a problem relating to SUN OS3.5 kernel device drivers. I want to
>measure the performance of the driver by calling a routine at certain
>points in the driver which records a timer value in a buffer somewhere.
>Outside the kernel, the obvious answer is to use gettimeofday(), but this
>is no good inside the device driver.
>
>Is there a way of accessing the SUN's timer register from within the
>kernel? Is there an easier way?

Here at UCB we built a microsecond resolution timer that plugs into the
DES chip of 3/50,3/60,3/160,3/260,4/110,4/260 class systems.  You'll have
a hard time using Sun's 20 (or 10) millisecond clock to instrument device
driver code.    Contact me for the schematic or to buy a finished timer
and device driver.

Peter Danzig
danzig@ucbarpa.berkeley.edu