diff options
author | Philippe Langlais <philippe.langlais@stericsson.com> | 2012-06-04 19:46:24 +0800 |
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committer | Philippe Langlais <philippe.langlais@stericsson.com> | 2012-06-04 19:46:24 +0800 |
commit | 29a3e1ef73daaa91cbf5cce2fb475f1878254402 (patch) | |
tree | fbd1df992706a4786633a7986a31b9cf78b3dced /Documentation | |
parent | 564119271649aa2d1840e79badf743e957b497e6 (diff) | |
parent | 3c16bd7bb0a2b00b71f65bb0075e0c94d0fcc777 (diff) |
Merge Linaro Android branch ' jstultz/linaro-android-3.4
' into integration-android-ux500
Signed-off-by: Philippe Langlais <philippe.langlais@stericsson.com>
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/android.txt | 121 | ||||
-rw-r--r-- | Documentation/cgroups/cgroups.txt | 9 | ||||
-rw-r--r-- | Documentation/cpu-freq/governors.txt | 59 |
3 files changed, 189 insertions, 0 deletions
diff --git a/Documentation/android.txt b/Documentation/android.txt new file mode 100644 index 00000000000..72a62afdf20 --- /dev/null +++ b/Documentation/android.txt @@ -0,0 +1,121 @@ + ============= + A N D R O I D + ============= + +Copyright (C) 2009 Google, Inc. +Written by Mike Chan <mike@android.com> + +CONTENTS: +--------- + +1. Android + 1.1 Required enabled config options + 1.2 Required disabled config options + 1.3 Recommended enabled config options +2. Contact + + +1. Android +========== + +Android (www.android.com) is an open source operating system for mobile devices. +This document describes configurations needed to run the Android framework on +top of the Linux kernel. + +To see a working defconfig look at msm_defconfig or goldfish_defconfig +which can be found at http://android.git.kernel.org in kernel/common.git +and kernel/msm.git + + +1.1 Required enabled config options +----------------------------------- +After building a standard defconfig, ensure that these options are enabled in +your .config or defconfig if they are not already. Based off the msm_defconfig. +You should keep the rest of the default options enabled in the defconfig +unless you know what you are doing. + +ANDROID_PARANOID_NETWORK +ASHMEM +CONFIG_FB_MODE_HELPERS +CONFIG_FONT_8x16 +CONFIG_FONT_8x8 +CONFIG_YAFFS_SHORT_NAMES_IN_RAM +DAB +EARLYSUSPEND +FB +FB_CFB_COPYAREA +FB_CFB_FILLRECT +FB_CFB_IMAGEBLIT +FB_DEFERRED_IO +FB_TILEBLITTING +HIGH_RES_TIMERS +INOTIFY +INOTIFY_USER +INPUT_EVDEV +INPUT_GPIO +INPUT_MISC +LEDS_CLASS +LEDS_GPIO +LOCK_KERNEL +LkOGGER +LOW_MEMORY_KILLER +MISC_DEVICES +NEW_LEDS +NO_HZ +POWER_SUPPLY +PREEMPT +RAMFS +RTC_CLASS +RTC_LIB +SWITCH +SWITCH_GPIO +TMPFS +UID_STAT +UID16 +USB_FUNCTION +USB_FUNCTION_ADB +USER_WAKELOCK +VIDEO_OUTPUT_CONTROL +WAKELOCK +YAFFS_AUTO_YAFFS2 +YAFFS_FS +YAFFS_YAFFS1 +YAFFS_YAFFS2 + + +1.2 Required disabled config options +------------------------------------ +CONFIG_YAFFS_DISABLE_LAZY_LOAD +DNOTIFY + + +1.3 Recommended enabled config options +------------------------------ +ANDROID_PMEM +ANDROID_RAM_CONSOLE +ANDROID_RAM_CONSOLE_ERROR_CORRECTION +SCHEDSTATS +DEBUG_PREEMPT +DEBUG_MUTEXES +DEBUG_SPINLOCK_SLEEP +DEBUG_INFO +FRAME_POINTER +CPU_FREQ +CPU_FREQ_TABLE +CPU_FREQ_DEFAULT_GOV_ONDEMAND +CPU_FREQ_GOV_ONDEMAND +CRC_CCITT +EMBEDDED +INPUT_TOUCHSCREEN +I2C +I2C_BOARDINFO +LOG_BUF_SHIFT=17 +SERIAL_CORE +SERIAL_CORE_CONSOLE + + +2. Contact +========== +website: http://android.git.kernel.org + +mailing-lists: android-kernel@googlegroups.com diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt index 8e74980ab38..594ff17d9da 100644 --- a/Documentation/cgroups/cgroups.txt +++ b/Documentation/cgroups/cgroups.txt @@ -592,6 +592,15 @@ there are not tasks in the cgroup. If pre_destroy() returns error code, rmdir() will fail with it. From this behavior, pre_destroy() can be called multiple times against a cgroup. +int allow_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) +(cgroup_mutex held by caller) + +Called prior to moving a task into a cgroup; if the subsystem +returns an error, this will abort the attach operation. Used +to extend the permission checks - if all subsystems in a cgroup +return 0, the attach will be allowed to proceed, even if the +default permission check (root or same user) fails. + int can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) (cgroup_mutex held by caller) diff --git a/Documentation/cpu-freq/governors.txt b/Documentation/cpu-freq/governors.txt index c7a2eb8450c..6aed1ce3673 100644 --- a/Documentation/cpu-freq/governors.txt +++ b/Documentation/cpu-freq/governors.txt @@ -28,6 +28,7 @@ Contents: 2.3 Userspace 2.4 Ondemand 2.5 Conservative +2.6 Interactive 3. The Governor Interface in the CPUfreq Core @@ -191,6 +192,64 @@ governor but for the opposite direction. For example when set to its default value of '20' it means that if the CPU usage needs to be below 20% between samples to have the frequency decreased. + +2.6 Interactive +--------------- + +The CPUfreq governor "interactive" is designed for latency-sensitive, +interactive workloads. This governor sets the CPU speed depending on +usage, similar to "ondemand" and "conservative" governors. However, +the governor is more aggressive about scaling the CPU speed up in +response to CPU-intensive activity. + +Sampling the CPU load every X ms can lead to under-powering the CPU +for X ms, leading to dropped frames, stuttering UI, etc. Instead of +sampling the cpu at a specified rate, the interactive governor will +check whether to scale the cpu frequency up soon after coming out of +idle. When the cpu comes out of idle, a timer is configured to fire +within 1-2 ticks. If the cpu is very busy between exiting idle and +when the timer fires then we assume the cpu is underpowered and ramp +to MAX speed. + +If the cpu was not sufficiently busy to immediately ramp to MAX speed, +then governor evaluates the cpu load since the last speed adjustment, +choosing the highest value between that longer-term load or the +short-term load since idle exit to determine the cpu speed to ramp to. + +The tuneable values for this governor are: + +min_sample_time: The minimum amount of time to spend at the current +frequency before ramping down. This is to ensure that the governor has +seen enough historic cpu load data to determine the appropriate +workload. Default is 80000 uS. + +hispeed_freq: An intermediate "hi speed" at which to initially ramp +when CPU load hits the value specified in go_hispeed_load. If load +stays high for the amount of time specified in above_hispeed_delay, +then speed may be bumped higher. Default is maximum speed. + +go_hispeed_load: The CPU load at which to ramp to the intermediate "hi +speed". Default is 85%. + +above_hispeed_delay: Once speed is set to hispeed_freq, wait for this +long before bumping speed higher in response to continued high load. +Default is 20000 uS. + +timer_rate: Sample rate for reevaluating cpu load when the system is +not idle. Default is 20000 uS. + +input_boost: If non-zero, boost speed of all CPUs to hispeed_freq on +touchscreen activity. Default is 0. + +boost: If non-zero, immediately boost speed of all CPUs to at least +hispeed_freq until zero is written to this attribute. If zero, allow +CPU speeds to drop below hispeed_freq according to load as usual. + +boostpulse: Immediately boost speed of all CPUs to hispeed_freq for +min_sample_time, after which speeds are allowed to drop below +hispeed_freq according to load as usual. + + 3. The Governor Interface in the CPUfreq Core ============================================= |