From 1c2562459faedc35927546cfa5273ec6c2884cce Mon Sep 17 00:00:00 2001 From: Thomas Renninger Date: Tue, 2 Oct 2007 13:28:12 -0700 Subject: [CPUFREQ] allow ondemand and conservative cpufreq governors to be used as default Depending on the transition latency of the HW for cpufreq switches, the ondemand or conservative governor cannot be used with certain cpufreq drivers. Still the ondemand should be the default governor on a wide range of systems. This patch allows this and lets the governor fallback to the performance governor at cpufreq driver load time, if the driver does not support fast enough frequency switching. Main benefit is that on e.g. installation or other systems without userspace support a working dynamic cpufreq support can be achieved on most systems by simply loading the cpufreq driver. This is especially essential for recent x86(_64) laptop hardware which may rely on working dynamic cpufreq OS support. Signed-off-by: Thomas Renninger Signed-off-by: Venkatesh Pallipadi Cc: Russell King Cc: Bryan Wu Cc: Andi Kleen Cc: "Luck, Tony" Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Paul Mundt Cc: "David S. Miller" Signed-off-by: Andrew Morton Signed-off-by: Dave Jones --- include/linux/cpufreq.h | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 3ec6e7ff5fb..9e5f5d0c87f 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -155,6 +155,9 @@ struct cpufreq_governor { char name[CPUFREQ_NAME_LEN]; int (*governor) (struct cpufreq_policy *policy, unsigned int event); + unsigned int max_transition_latency; /* HW must be able to switch to + next freq faster than this value in nano secs or we + will fallback to performance governor */ struct list_head governor_list; struct module *owner; }; @@ -279,12 +282,23 @@ static inline unsigned int cpufreq_quick_get(unsigned int cpu) *********************************************************************/ -#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE +/* + Performance governor is fallback governor if any other gov failed to + auto load due latency restrictions +*/ extern struct cpufreq_governor cpufreq_gov_performance; -#define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_performance +#define CPUFREQ_PERFORMANCE_GOVERNOR (&cpufreq_gov_performance) +#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE +#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance) #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE) extern struct cpufreq_governor cpufreq_gov_userspace; -#define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_userspace +#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace) +#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND) +extern struct cpufreq_governor cpufreq_gov_ondemand; +#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand) +#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE) +extern struct cpufreq_governor cpufreq_gov_conservative; +#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative) #endif -- cgit v1.2.3 From 6afde10c3f58cc3ac593f5b4505b8b1cf719f5d6 Mon Sep 17 00:00:00 2001 From: Thomas Renninger Date: Tue, 2 Oct 2007 13:28:13 -0700 Subject: [CPUFREQ] Only check for transition latency on problematic governors (kconfig fix) Cc: Adrian Bunk Signed-off-by: Andrew Morton Signed-off-by: Dave Jones --- include/linux/cpufreq.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 9e5f5d0c87f..450a841b589 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -286,8 +286,9 @@ static inline unsigned int cpufreq_quick_get(unsigned int cpu) Performance governor is fallback governor if any other gov failed to auto load due latency restrictions */ +#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE extern struct cpufreq_governor cpufreq_gov_performance; -#define CPUFREQ_PERFORMANCE_GOVERNOR (&cpufreq_gov_performance) +#endif #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance) #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE) -- cgit v1.2.3 From 6070b5de50ab5e3f810628a9cbb04deecf30a85f Mon Sep 17 00:00:00 2001 From: Satyam Sharma Date: Tue, 2 Oct 2007 13:28:15 -0700 Subject: [CPUFREQ] implement !CONFIG_CPU_FREQ stub for cpufreq_unregister_notifier() Callsites such as arch/powerpc/oprofile/op_model_cell.c are having to open-code #ifdef CONFIG_CPU_FREQ only to be able to get at the full definition of cpufreq_unregister_notifier(), because no empty stub is available for the !CONFIG_CPU_FREQ case. Let's provide one, to be able to remove such #ifdef's from the rest of the kernel tree -- those will come in a subsequent patch. Signed-off-by: Satyam Sharma Signed-off-by: Andrew Morton Signed-off-by: Dave Jones --- include/linux/cpufreq.h | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 450a841b589..23932d7741a 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -32,12 +32,24 @@ * CPUFREQ NOTIFIER INTERFACE * *********************************************************************/ -int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list); -int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list); - #define CPUFREQ_TRANSITION_NOTIFIER (0) #define CPUFREQ_POLICY_NOTIFIER (1) +#ifdef CONFIG_CPU_FREQ +int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list); +int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list); +#else /* CONFIG_CPU_FREQ */ +static inline int cpufreq_register_notifier(struct notifier_block *nb, + unsigned int list) +{ + return 0; +} +static inline int cpufreq_unregister_notifier(struct notifier_block *nb, + unsigned int list) +{ + return 0; +} +#endif /* CONFIG_CPU_FREQ */ /* if (cpufreq_driver->target) exists, the ->governor decides what frequency * within the limits is used. If (cpufreq_driver->setpolicy> exists, these -- cgit v1.2.3