From: 黄涛 <huangtao@rock-chips.com> Date: Wed, 22 Aug 2012 06:42:16 +0000 (+0800) Subject: Revert "cpufreq: introduce hotplug governor" X-Git-Tag: firefly_0821_release~8865 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=4839f665f5d22d65c8f1542f5e75a4a531893d83;p=firefly-linux-kernel-4.4.55.git Revert "cpufreq: introduce hotplug governor" This reverts commit 1b02ab5fd585f88b65379b81874c75f66eec6492. --- diff --git a/Documentation/cpu-freq/governors.txt b/Documentation/cpu-freq/governors.txt index da3cfb34825d..963a543bde4d 100644 --- a/Documentation/cpu-freq/governors.txt +++ b/Documentation/cpu-freq/governors.txt @@ -252,33 +252,6 @@ min_sample_time, after which speeds are allowed to drop below hispeed_freq according to load as usual. -2.7 Hotplug ------------ - -The CPUfreq governor "hotplug" operates similary to "ondemand" and -"conservative". It's decisions are based primarily on CPU load. Like -"ondemand" the "hotplug" governor will ramp up to the highest frequency -once the run-time tunable "up_threshold" parameter is crossed. Like -"conservative", the "hotplug" governor exports a "down_threshold" -parameter that is also tunable at run-time. When the "down_threshold" -is crossed the CPU transitions to the next lowest frequency in the -CPUfreq frequency table instead of decrementing the frequency based on a -percentage of maximum load. - -The main reason "hotplug" governor exists is for architectures requiring -that only the master CPU be online in order to hit low-power states -(C-states). OMAP4 is one such example of this. The "hotplug" governor -is also helpful in reducing thermal output in devices with tight thermal -constraints. - -Auxillary CPUs are onlined/offline based on CPU load, but the decision -to do so is made after averaging several sampling windows. This is to -reduce CPU hotplug "thrashing", which can be caused by normal system -entropy and leads to lots of spurious plug-in and plug-out transitions. -The number of sampling periods averaged together is tunable via the -"hotplug_in_sampling_periods" and "hotplug_out_sampling_periods" -run-time tunable parameters. - 3. The Governor Interface in the CPUfreq Core ============================================= diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig index f2f64a0b72c5..194708850ede 100644 --- a/drivers/cpufreq/Kconfig +++ b/drivers/cpufreq/Kconfig @@ -109,19 +109,6 @@ config CPU_FREQ_DEFAULT_GOV_INTERACTIVE loading your cpufreq low-level hardware driver, using the 'interactive' governor for latency-sensitive workloads. -config CPU_FREQ_DEFAULT_GOV_HOTPLUG - bool "hotplug" - select CPU_FREQ_GOV_HOTPLUG - select CPU_FREQ_GOV_PERFORMANCE - help - Use the CPUFreq governor 'hotplug' as default. This allows you - to get a full dynamic frequency capable system with CPU - hotplug support by simply loading your cpufreq low-level - hardware driver. Be aware that not all cpufreq drivers - support the hotplug governor. If unsure have a look at - the help section of the driver. Fallback governor will be the - performance governor. - endchoice config CPU_FREQ_GOV_PERFORMANCE @@ -224,25 +211,5 @@ depends on X86 source "drivers/cpufreq/Kconfig.x86" endmenu -config CPU_FREQ_GOV_HOTPLUG - tristate "'hotplug' cpufreq governor" - depends on CPU_FREQ && NO_HZ && HOTPLUG_CPU - help - 'hotplug' - this driver mimics the frequency scaling behavior - in 'ondemand', but with several key differences. First is - that frequency transitions use the CPUFreq table directly, - instead of incrementing in a percentage of the maximum - available frequency. Second 'hotplug' will offline auxillary - CPUs when the system is idle, and online those CPUs once the - system becomes busy again. This last feature is needed for - architectures which transition to low power states when only - the "master" CPU is online, or for thermally constrained - devices. - - If you don't have one of these architectures or devices, use - 'ondemand' instead. - - If in doubt, say N. - endif endmenu diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile index 1a5e64d6fcf3..c044060a4b07 100644 --- a/drivers/cpufreq/Makefile +++ b/drivers/cpufreq/Makefile @@ -10,7 +10,6 @@ obj-$(CONFIG_CPU_FREQ_GOV_USERSPACE) += cpufreq_userspace.o obj-$(CONFIG_CPU_FREQ_GOV_ONDEMAND) += cpufreq_ondemand.o obj-$(CONFIG_CPU_FREQ_GOV_CONSERVATIVE) += cpufreq_conservative.o obj-$(CONFIG_CPU_FREQ_GOV_INTERACTIVE) += cpufreq_interactive.o -obj-$(CONFIG_CPU_FREQ_GOV_HOTPLUG) += cpufreq_hotplug.o # CPUfreq cross-arch helpers obj-$(CONFIG_CPU_FREQ_TABLE) += freq_table.o diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 6f492ea8a1ac..ae06dc9a0cda 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -361,9 +361,6 @@ extern struct cpufreq_governor cpufreq_gov_conservative; #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE) extern struct cpufreq_governor cpufreq_gov_interactive; #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_interactive) -#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_HOTPLUG) -extern struct cpufreq_governor cpufreq_gov_hotplug; -#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_hotplug) #endif