Tue Aug 10 02:43:50 2010 UTC ()
Note the gathered statistics. One CAVEAT down.


(jruoho)
diff -r1.5 -r1.6 src/share/man/man4/acpicpu.4
cvs diff -r1.5 -r1.6 src/share/man/man4/acpicpu.4 (expand / switch to unified diff)

--- src/share/man/man4/acpicpu.4 2010/08/09 16:13:21 1.5
+++ src/share/man/man4/acpicpu.4 2010/08/10 02:43:50 1.6
@@ -1,40 +1,40 @@ @@ -1,40 +1,40 @@
1.\" $NetBSD: acpicpu.4,v 1.5 2010/08/09 16:13:21 jruoho Exp $ 1.\" $NetBSD: acpicpu.4,v 1.6 2010/08/10 02:43:50 jruoho Exp $
2.\" 2.\"
3.\" Coyright (c) 2010 Jukka Ruohonen <jruohonen@iki.fi> 3.\" Coyright (c) 2010 Jukka Ruohonen <jruohonen@iki.fi>
4.\" All rights reserved. 4.\" All rights reserved.
5.\" 5.\"
6.\" Redistribution and use in source and binary forms, with or without 6.\" Redistribution and use in source and binary forms, with or without
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13.\" from this software without specific prior written permission. 13.\" from this software without specific prior written permission.
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27.Dd August 9, 2010 27.Dd August 10, 2010
28.Dt ACPICPU 4 28.Dt ACPICPU 4
29.Os 29.Os
30.Sh NAME 30.Sh NAME
31.Nm acpicpu 31.Nm acpicpu
32.Nd ACPI CPU 32.Nd ACPI CPU
33.Sh SYNOPSIS 33.Sh SYNOPSIS
34.Cd "acpicpu* at acpi?" 34.Cd "acpicpu* at acpi?"
35.Sh DESCRIPTION 35.Sh DESCRIPTION
36The 36The
37.Nm 37.Nm
38device driver supports certain processor features that are 38device driver supports certain processor features that are
39either only available via 39either only available via
40.Tn ACPI 40.Tn ACPI
@@ -176,26 +176,36 @@ frequency management, @@ -176,26 +176,36 @@ frequency management,
176.Tn ACPI 176.Tn ACPI
177provides support for Dynamic Frequency and Voltage Scaling 177provides support for Dynamic Frequency and Voltage Scaling
178.Pq Tn DVFS . 178.Pq Tn DVFS .
179This means that the firmware may request the implementation to 179This means that the firmware may request the implementation to
180dynamically scale the presently supported maximum clock frequency. 180dynamically scale the presently supported maximum clock frequency.
181For example, if 181For example, if
182.Xr acpiacad 4 182.Xr acpiacad 4
183is disconnected, the maximum available frequency may be lowered. 183is disconnected, the maximum available frequency may be lowered.
184Currently the 184Currently the
185.Nx 185.Nx
186implementation reacts to these events by imposing the dynamic maximum, but 186implementation reacts to these events by imposing the dynamic maximum, but
187.Nm 187.Nm
188does not take any actions to manipulate the frequencies by itself. 188does not take any actions to manipulate the frequencies by itself.
 189.Ss Statistics
 190The
 191.Nm
 192driver uses event counters to track the times
 193a processor has entered a given state.
 194It is possible to view the statistics by using
 195.Xr vmstat 1
 196(with the argument
 197.Ar -e ) .
 198Note that valid per-CPU data is available only for C-states.
189.Sh SEE ALSO 199.Sh SEE ALSO
190.Xr acpi 4 , 200.Xr acpi 4 ,
191.Xr cpu_idle 9 201.Xr cpu_idle 9
192.Sh HISTORY 202.Sh HISTORY
193The 203The
194.Nm 204.Nm
195device driver appeared in 205device driver appeared in
196.Nx 6.0 . 206.Nx 6.0 .
197.Sh AUTHORS 207.Sh AUTHORS
198.An Jukka Ruohonen 208.An Jukka Ruohonen
199.Aq jruohonen@iki.fi 209.Aq jruohonen@iki.fi
200.Sh CAVEATS 210.Sh CAVEATS
201The 211The
@@ -227,21 +237,14 @@ Neither processor thermal control (see @@ -227,21 +237,14 @@ Neither processor thermal control (see
227.Xr acpitz 4 ) 237.Xr acpitz 4 )
228nor 238nor
229.Dq throttling 239.Dq throttling
230are currently supported. 240are currently supported.
231.It 241.It
232There is currently neither a well-defined, machine-independent 242There is currently neither a well-defined, machine-independent
233.Tn API 243.Tn API
234for processor performance management nor a 244for processor performance management nor a
235.Dq governor 245.Dq governor
236for different policies. 246for different policies.
237It is only possible to control the 247It is only possible to control the
238.Tn CPU 248.Tn CPU
239frequencies from userland. 249frequencies from userland.
240.It 
241There are currently no proper ways to export 
242statistical and other information from 
243.Nm . 
244This applies to 
245.Tn ACPI 
246generally. 
247.El 250.El