debuggers.hg

changeset 20862:757359a36785

Change default cpufreq governor to ondemand

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>
author Keir Fraser <keir.fraser@citrix.com>
date Sun Jan 17 18:07:10 2010 +0000 (2010-01-17)
parents ff2d29e6ab9c
children 7a8cee80597e
files xen/include/acpi/cpufreq/cpufreq.h
line diff
     1.1 --- a/xen/include/acpi/cpufreq/cpufreq.h	Sun Jan 17 18:05:32 2010 +0000
     1.2 +++ b/xen/include/acpi/cpufreq/cpufreq.h	Sun Jan 17 18:07:10 2010 +0000
     1.3 @@ -100,7 +100,7 @@ extern struct cpufreq_governor cpufreq_g
     1.4  extern int cpufreq_register_governor(struct cpufreq_governor *governor);
     1.5  extern int cpufreq_unregister_governor(struct cpufreq_governor *governor);
     1.6  extern struct cpufreq_governor *__find_governor(const char *governor);
     1.7 -#define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_userspace
     1.8 +#define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_dbs
     1.9  
    1.10  /* pass a target to the cpufreq driver */
    1.11  extern int __cpufreq_driver_target(struct cpufreq_policy *policy,