[elrepo] No ondemand cpuspeed with 3.18.2-1.el6 kernel

[Robert Nichols]

On 01/15/2015 07:23 PM, Akemi Yagi wrote:
> On Wed, Jan 14, 2015 at 11:59 PM, Robert Nichols
> <rnicholsNOSPAM at comcast.net> wrote:
>
>> With my patch, the script does load the cpufreq_ondemand module, and
>> that succeeds (it shows up in lsmod), but only "performance" and "powersave"
>> show up in /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors
>
>  From what I've read so far, the intel_pstate driver only supports the
> performance and the powersave governors. In newer kernels, this driver
> is used for newer processors such as sandy bridge and ivy bridge.
>
> I found this article informative:
>
> https://wiki.archlinux.org/index.php/CPU_frequency_scaling

Thanks for the link. It confirms what I've seen. The intel_pstate governor
is built into the kernel, and therefore the "cpuspeed" service does not
even need to be run at all.  I've put a patch (attached) in the
/etc/sysconfig/cpuspeed config file to bail out (successfully) if anything
tries to start that service in a kernel version 3.17 or newer.  (Of course
I've taken out the patch I had made to the init.d/cpuspeed file.)

The governor that they are calling "powersave" actually behaves like the
old "ondemand" governor.  The frequency will be adjusted up and down as
needed.

-- 
Bob Nichols     "NOSPAM" is really part of my email address.
                 Do NOT delete it.
-------------- next part --------------
--- /etc/sysconfig/cpuspeed.orig	2013-08-13 07:48:16.000000000 -0500
+++ /etc/sysconfig/cpuspeed	2015-01-15 19:39:13.569121045 -0600
@@ -25,7 +25,27 @@
 #   which provides said user-space frequency scaling.
 # default value: empty (defaults to ondemand on centrino, powernow-k8,
 #                       and acpi-cpufreq systems, userspace on others)
-GOVERNOR=
+Kern=$(uname -r)
+Kmajor=${Kern%%.*}
+Kminor=${Kern#$Kmajor.}
+Kminor=${Kminor%%.*}
+case $Kmajor in
+2)
+    ;;
+3)  if [[ $Kminor -ge 17 && $1 != status ]]; then # Service is not needed
+        Cmd=${0##*/}
+	Cmd=${Cmd#[SK][0-9][0-9]}
+        echo -n "Ignoring $Cmd $1 in kernel ${Kmajor}.${Kminor}"
+	success; echo
+        exit 0
+#        GOVERNOR=powersave
+    fi
+    ;;
+*)
+    echo "$0: Unknown kernel version: $Kernel" >&2
+    exit 1
+    ;;
+esac
 
 ### FREQUENCIES ###
 # NOTE: valid max/min frequencies for your cpu(s) can be found in