[PATCH] Change default cpufreq governor to ondemand

[PATCH] Change default cpufreq governor to ondemand

[John Haxby]

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Back in c/s 18950 the default cpufreq governor was set to userspace (it 
had previously been performance).  However, since there is no supplied 
userspace program or script that will change the frequency this is at 
best a no-op.  Worse, on some hardware with some BIOS revisions, this 
actually sets the CPUs running at their lowest frequency rather than 
their highest and there is a corresponding (and initially puzzling) drop 
in performance.

This patch changes the default governor to "ondemand" which should make 
it the same as the Linux default and will provide power savings for the 
majority without needing to write a userspace governor.  For those that 
want to install their own governor, that is still possible.

Signed-off-by: John Haxby <john.haxby@oracle.com>

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diff -r 88d2273c3942 xen/include/acpi/cpufreq/cpufreq.h
--- a/xen/include/acpi/cpufreq/cpufreq.h	Fri Jan 15 08:27:27 2010 +0000
+++ b/xen/include/acpi/cpufreq/cpufreq.h	Fri Jan 15 16:07:03 2010 +0000
@@ -100,7 +100,7 @@
 extern int cpufreq_register_governor(struct cpufreq_governor *governor);
 extern int cpufreq_unregister_governor(struct cpufreq_governor *governor);
 extern struct cpufreq_governor *__find_governor(const char *governor);
-#define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_userspace
+#define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_dbs;
 
 /* pass a target to the cpufreq driver */
 extern int __cpufreq_driver_target(struct cpufreq_policy *policy,

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Re: [PATCH] Change default cpufreq governor to ondemand

[John Haxby]

On 15/01/10 16:25, John Haxby wrote:
> +#define CPUFREQ_DEFAULT_GOVERNOR&cpufreq_gov_dbs;

Thanks for fixing the typo, Kier.

jch