cpufreq: allow customization of some parameters

Short of having a way for powersaved to dynamically adjust these
values, at least allow specifying them on the command line. In
particular, always running at an up-threshold of 80% is perhaps nice
for laptop use, but certainly not desirable on servers. On shell
scripts invoking large numbers of short-lived processes I noticed a
50% performance degradation on a dual-socket quad-core Barcelona just
because of the load of an individual core never crossing the 80%
boundary that would have resulted in increasing the frequency.

(Powersaved on SLE10 sets this on native kernels to 60% or 80%,
depending on whether performance or power reduction is preferred,
*divided* by the number of CPUs, but capped at the lower limit of
20%.)

Signed-off-by: Jan Beulich <jbeulich@novell.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/xen/include/acpi/cpufreq/cpufreq.h b/xen/include/acpi/cpufreq/cpufreq.h
index 77824417ed..25b6ce7316 100644
--- a/xen/include/acpi/cpufreq/cpufreq.h
+++ b/xen/include/acpi/cpufreq/cpufreq.h
@@ -55,6 +55,8 @@ extern struct cpufreq_policy *cpufreq_cpu_policy[NR_CPUS];
 extern int __cpufreq_set_policy(struct cpufreq_policy *data,
                                 struct cpufreq_policy *policy);
 
+void cpufreq_cmdline_parse(char *);
+
 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
 #define CPUFREQ_SHARED_TYPE_HW   (1) /* HW does needed coordination */
 #define CPUFREQ_SHARED_TYPE_ALL  (2) /* All dependent CPUs should set freq */