From: Michael Vallaly <vaio@nolatency.com>
To: cpufreq@www.linux.org.uk
Cc: vaio@nolatency.com
Subject: 2.6.0-test1 CpuFreq Speedstep Quirks
Date: Thu, 17 Jul 2003 14:48:42 +0000 [thread overview]
Message-ID: <20030717144842.70a5d7b3.vaio@nolatency.com> (raw)
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Hello,
After testing the 2.6.0-test1 kernel with CPUfreq scaling compiled in (+userspace govenor) I have noticed some changes in the way the kernel detects and prints my CPU information. Along these lines some programs (in peticular, mplayer and xmms) have some issues syncing (apparently time critical / cpu speed critical code.) As of right now these issues only seem to disappear if I run in powersave mode. Im not quite sure if this is a bug or not as I am quite new to cpu frequency scaling issues. If this is not a bug / problem maybe someone can help enlighten me as to what is actually occuring. I would be willing to test anything speedstep / cpufreq related as I have quite a bit of freetime until August 25th. Attached are few screenshots of the interesting quirks with Cpufreq installed. Thanks for you time..
- Mike
Michael Vallaly
vaio@nolatency.com
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CPU INFO 2.6.0-test1 no CPUfreq
=================================
root@vaio:~$ uname -a
Linux vaio 2.6.0-test1 #2 Thu Jul 17 14:15:59 UTC 2003 i686 unknown
root@vaio:~$ cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 11
model name : Mobile Intel(R) Pentium(R) III CPU - M 900MHz
stepping : 4
cpu MHz : 894.445
cache size : 512 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 2
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 mmx fxsr sse
bogomips : 1765.37
root@vaio:~$ /bogomips
Calibrating delay loop.. ok - 864.00 BogoMips
CPU INFO 2.6.0-test1 with CPUfreq
===================================
root@vaio:/sys/devices/system/cpu/cpu0/cpufreq$ uname -a
Linux vaio 2.6.0-test1 #1 Mon Jul 14 18:07:26 UTC 2003 i686 unknown
root@vaio:/sys/devices/system/cpu/cpu0/cpufreq$ cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 11
model name : Mobile Intel(R) Pentium(R) III CPU - M 900MHz
stepping : 4
cpu MHz : 496.891 <--- Reports a 500mhz machine yet the Scaling_governor is set / defaults to performance
cache size : 512 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 2
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 mmx fxsr sse
bogomips : 980.76 <--- This number has never changed throughout my testing.. as such I decided
to use the bogomips program to show the change in CPU frequency.
root@vaio:/sys/devices/system/cpu/cpu0/cpufreq$ ls -l
total 0
-r--r--r-- 1 root root 4096 Jul 14 18:29 cpuinfo_max_freq
-r--r--r-- 1 root root 4096 Jul 14 18:29 cpuinfo_min_freq
-r--r--r-- 1 root root 4096 Jul 14 18:29 scaling_available_governors
-r--r--r-- 1 root root 4096 Jul 14 18:29 scaling_driver
-rw-r--r-- 1 root root 0 Jul 17 13:31 scaling_governor
-rw-r--r-- 1 root root 4096 Jul 14 18:29 scaling_max_freq
-rw-r--r-- 1 root root 4096 Jul 14 18:29 scaling_min_freq
root@vaio:/sys/devices/system/cpu/cpu0/cpufreq$ cat *
900000
500000
performance powersave userspace
speedstep
performance
900000
500000
root@vaio:/sys/devices/system/cpu/cpu0/cpufreq$ /bogomips
Calibrating delay loop.. ok - 858.00 BogoMips
root@vaio:/sys/devices/system/cpu/cpu0/cpufreq$ echo powersave > scaling_governor
root@vaio:/sys/devices/system/cpu/cpu0/cpufreq$ cat *
900000
500000
performance powersave userspace
speedstep
powersave <--- Looks good
900000
500000
root@vaio:/sys/devices/system/cpu/cpu0/cpufreq$ /bogomips
Calibrating delay loop.. ok - 474.00 BogoMips <--- CPU Speed changed
====================================================================
Scaling_Governor seems to scale the processor.. ;)
====================================================================
Example #2 using userspace driver
==================================
root@vaio:/sys/devices/system/cpu/cpu0/cpufreq$ echo userspace > scaling_governor
root@vaio:/sys/devices/system/cpu/cpu0/cpufreq$ ls -l
total 0
-r--r--r-- 1 root root 4096 Jul 14 18:29 cpuinfo_max_freq
-r--r--r-- 1 root root 4096 Jul 14 18:29 cpuinfo_min_freq
-r--r--r-- 1 root root 4096 Jul 14 18:29 scaling_available_governors
-r--r--r-- 1 root root 4096 Jul 14 18:29 scaling_driver
-rw-r--r-- 1 root root 0 Jul 17 13:40 scaling_governor
-rw-r--r-- 1 root root 4096 Jul 14 18:29 scaling_max_freq
-rw-r--r-- 1 root root 4096 Jul 14 18:29 scaling_min_freq
-rw-r--r-- 1 root root 4096 Jul 17 13:40 scaling_setspeed
root@vaio:/sys/devices/system/cpu/cpu0/cpufreq$ cat *
900000
500000
performance powersave userspace
speedstep
userspace
900000
500000
500000
root@vaio:/sys/devices/system/cpu/cpu0/cpufreq$ /bogomips
Calibrating delay loop.. ok - 470.00 BogoMips
root@vaio:/sys/devices/system/cpu/cpu0/cpufreq$ echo 900000 > scaling_setspeed
root@vaio:/sys/devices/system/cpu/cpu0/cpufreq$ cat *
900000
500000
performance powersave userspace
speedstep
userspace
900000
500000
500000 <---- Note the scaling_setspeed did NOT change
root@vaio:/sys/devices/system/cpu/cpu0/cpufreq$ /bogomips
Calibrating delay loop.. ok - 864.00 BogoMips <---- Yet apparently the processor speed did.
========================================================================
Thanks for your help..
-Mike
next reply other threads:[~2003-07-17 14:48 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-07-17 14:48 Michael Vallaly [this message]
2003-07-18 6:16 ` 2.6.0-test1 CpuFreq Speedstep Quirks Dominik Brodowski
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