diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/android.txt | 121 | ||||
| -rw-r--r-- | Documentation/arm64/tagged-pointers.txt | 34 | ||||
| -rw-r--r-- | Documentation/cgroups/cgroups.txt | 9 | ||||
| -rw-r--r-- | Documentation/cpu-freq/governors.txt | 85 | ||||
| -rw-r--r-- | Documentation/filesystems/proc.txt | 6 | ||||
| -rw-r--r-- | Documentation/networking/ip-sysctl.txt | 28 | ||||
| -rw-r--r-- | Documentation/sync.txt | 75 | ||||
| -rw-r--r-- | Documentation/sysctl/vm.txt | 16 | ||||
| -rw-r--r-- | Documentation/trace/ftrace.txt | 29 |
9 files changed, 403 insertions, 0 deletions
diff --git a/Documentation/android.txt b/Documentation/android.txt new file mode 100644 index 000000000000..0f40a78b045f --- /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 +PSTORE_CONSOLE +PSTORE_RAM +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/arm64/tagged-pointers.txt b/Documentation/arm64/tagged-pointers.txt new file mode 100644 index 000000000000..d9995f1f51b3 --- /dev/null +++ b/Documentation/arm64/tagged-pointers.txt @@ -0,0 +1,34 @@ + Tagged virtual addresses in AArch64 Linux + ========================================= + +Author: Will Deacon <will.deacon@arm.com> +Date : 12 June 2013 + +This document briefly describes the provision of tagged virtual +addresses in the AArch64 translation system and their potential uses +in AArch64 Linux. + +The kernel configures the translation tables so that translations made +via TTBR0 (i.e. userspace mappings) have the top byte (bits 63:56) of +the virtual address ignored by the translation hardware. This frees up +this byte for application use, with the following caveats: + + (1) The kernel requires that all user addresses passed to EL1 + are tagged with tag 0x00. This means that any syscall + parameters containing user virtual addresses *must* have + their top byte cleared before trapping to the kernel. + + (2) Non-zero tags are not preserved when delivering signals. + This means that signal handlers in applications making use + of tags cannot rely on the tag information for user virtual + addresses being maintained for fields inside siginfo_t. + One exception to this rule is for signals raised in response + to watchpoint debug exceptions, where the tag information + will be preserved. + + (3) Special care should be taken when using tagged pointers, + since it is likely that C compilers will not hazard two + virtual addresses differing only in the upper byte. + +The architecture prevents the use of a tagged PC, so the upper byte will +be set to a sign-extension of bit 55 on exception return. diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt index 638bf17ff869..61dc0ec5c9a9 100644 --- a/Documentation/cgroups/cgroups.txt +++ b/Documentation/cgroups/cgroups.txt @@ -598,6 +598,15 @@ is completely unused; @cgrp->parent is still valid. (Note - can also be called for a newly-created cgroup if an error occurs after this subsystem's create() method has been called for the new 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 219970ba54b7..875eecbed8c8 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 @@ -218,6 +219,90 @@ a decision on when to decrease the frequency while running in any speed. Load for frequency increase is still evaluated every sampling rate. +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, but with a +different set of configurable behaviors. + +The tuneable values for this governor are: + +target_loads: CPU load values used to adjust speed to influence the +current CPU load toward that value. In general, the lower the target +load, the more often the governor will raise CPU speeds to bring load +below the target. The format is a single target load, optionally +followed by pairs of CPU speeds and CPU loads to target at or above +those speeds. Colons can be used between the speeds and associated +target loads for readability. For example: + + 85 1000000:90 1700000:99 + +targets CPU load 85% below speed 1GHz, 90% at or above 1GHz, until +1.7GHz and above, at which load 99% is targeted. If speeds are +specified these must appear in ascending order. Higher target load +values are typically specified for higher speeds, that is, target load +values also usually appear in an ascending order. The default is +target load 90% for all speeds. + +min_sample_time: The minimum amount of time to spend at the current +frequency before ramping down. 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 the maximum speed +allowed by the policy at governor initialization time. + +go_hispeed_load: The CPU load at which to ramp to hispeed_freq. +Default is 99%. + +above_hispeed_delay: When speed is at or above hispeed_freq, wait for +this long before raising speed in response to continued high load. +The format is a single delay value, optionally followed by pairs of +CPU speeds and the delay to use at or above those speeds. Colons can +be used between the speeds and associated delays for readability. For +example: + + 80000 1300000:200000 1500000:40000 + +uses delay 80000 uS until CPU speed 1.3 GHz, at which speed delay +200000 uS is used until speed 1.5 GHz, at which speed (and above) +delay 40000 uS is used. If speeds are specified these must appear in +ascending order. Default is 20000 uS. + +timer_rate: Sample rate for reevaluating CPU load when the CPU is not +idle. A deferrable timer is used, such that the CPU will not be woken +from idle to service this timer until something else needs to run. +(The maximum time to allow deferring this timer when not running at +minimum speed is configurable via timer_slack.) Default is 20000 uS. + +timer_slack: Maximum additional time to defer handling the governor +sampling timer beyond timer_rate when running at speeds above the +minimum. For platforms that consume additional power at idle when +CPUs are running at speeds greater than minimum, this places an upper +bound on how long the timer will be deferred prior to re-evaluating +load and dropping speed. For example, if timer_rate is 20000uS and +timer_slack is 10000uS then timers will be deferred for up to 30msec +when not at lowest speed. A value of -1 means defer timers +indefinitely at all speeds. Default is 80000 uS. + +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. +Default is zero. + +boostpulse: On each write, immediately boost speed of all CPUs to +hispeed_freq for at least the period of time specified by +boostpulse_duration, after which speeds are allowed to drop below +hispeed_freq according to load as usual. + +boostpulse_duration: Length of time to hold CPU speed at hispeed_freq +on a write to boostpulse, before allowing speed to drop according to +load as usual. Default is 80000 uS. + + 3. The Governor Interface in the CPUfreq Core ============================================= diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index 954eab8c7fec..7ce8ef7d764a 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -369,6 +369,8 @@ is not associated with a file: [stack:1001] = the stack of the thread with tid 1001 [vdso] = the "virtual dynamic shared object", the kernel system call handler + [anon:<name>] = an anonymous mapping that has been + named by userspace or if empty, the mapping is anonymous. @@ -419,6 +421,7 @@ KernelPageSize: 4 kB MMUPageSize: 4 kB Locked: 374 kB VmFlags: rd ex mr mw me de +Name: name from userspace the first of these lines shows the same information as is displayed for the mapping in /proc/PID/maps. The remaining lines show the size of the mapping @@ -469,6 +472,9 @@ Note that there is no guarantee that every flag and associated mnemonic will be present in all further kernel releases. Things get changed, the flags may be vanished or the reverse -- new added. +The "Name" field will only be present on a mapping that has been named by +userspace, and will show the name passed in by userspace. + This file is only present if the CONFIG_MMU kernel configuration option is enabled. diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index a59ee432a98f..99d216418061 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -22,6 +22,15 @@ ip_no_pmtu_disc - BOOLEAN min_pmtu - INTEGER default 552 - minimum discovered Path MTU +fwmark_reflect - BOOLEAN + Controls the fwmark of kernel-generated IPv4 reply packets that are not + associated with a socket for example, TCP RSTs or ICMP echo replies). + If unset, these packets have a fwmark of zero. If set, they have the + fwmark of the packet they are replying to. Similarly affects the fwmark + used by internal routing lookups triggered by incoming packets, such as + the ones used for Path MTU Discovery. + Default: 0 + route/max_size - INTEGER Maximum number of routes allowed in the kernel. Increase this when using large numbers of interfaces and/or routes. @@ -468,6 +477,16 @@ tcp_fastopen - INTEGER See include/net/tcp.h and the code for more details. +tcp_fwmark_accept - BOOLEAN + If set, incoming connections to listening sockets that do not have a + socket mark will set the mark of the accepting socket to the fwmark of + the incoming SYN packet. This will cause all packets on that connection + (starting from the first SYNACK) to be sent with that fwmark. The + listening socket's mark is unchanged. Listening sockets that already + have a fwmark set via setsockopt(SOL_SOCKET, SO_MARK, ...) are + unaffected. + Default: 0 + tcp_syn_retries - INTEGER Number of times initial SYNs for an active TCP connection attempt will be retransmitted. Should not be higher than 255. Default value @@ -1093,6 +1112,15 @@ conf/all/forwarding - BOOLEAN proxy_ndp - BOOLEAN Do proxy ndp. +fwmark_reflect - BOOLEAN + Controls the fwmark of kernel-generated IPv6 reply packets that are not + associated with a socket for example, TCP RSTs or ICMPv6 echo replies). + If unset, these packets have a fwmark of zero. If set, they have the + fwmark of the packet they are replying to. Similarly affects the fwmark + used by internal routing lookups triggered by incoming packets, such as + the ones used for Path MTU Discovery. + Default: 0 + conf/interface/*: Change special settings per interface. diff --git a/Documentation/sync.txt b/Documentation/sync.txt new file mode 100644 index 000000000000..a2d05e7fa193 --- /dev/null +++ b/Documentation/sync.txt @@ -0,0 +1,75 @@ +Motivation: + +In complicated DMA pipelines such as graphics (multimedia, camera, gpu, display) +a consumer of a buffer needs to know when the producer has finished producing +it. Likewise the producer needs to know when the consumer is finished with the +buffer so it can reuse it. A particular buffer may be consumed by multiple +consumers which will retain the buffer for different amounts of time. In +addition, a consumer may consume multiple buffers atomically. +The sync framework adds an API which allows synchronization between the +producers and consumers in a generic way while also allowing platforms which +have shared hardware synchronization primitives to exploit them. + +Goals: + * provide a generic API for expressing synchronization dependencies + * allow drivers to exploit hardware synchronization between hardware + blocks + * provide a userspace API that allows a compositor to manage + dependencies. + * provide rich telemetry data to allow debugging slowdowns and stalls of + the graphics pipeline. + +Objects: + * sync_timeline + * sync_pt + * sync_fence + +sync_timeline: + +A sync_timeline is an abstract monotonically increasing counter. In general, +each driver/hardware block context will have one of these. They can be backed +by the appropriate hardware or rely on the generic sw_sync implementation. +Timelines are only ever created through their specific implementations +(i.e. sw_sync.) + +sync_pt: + +A sync_pt is an abstract value which marks a point on a sync_timeline. Sync_pts +have a single timeline parent. They have 3 states: active, signaled, and error. +They start in active state and transition, once, to either signaled (when the +timeline counter advances beyond the sync_pt’s value) or error state. + +sync_fence: + +Sync_fences are the primary primitives used by drivers to coordinate +synchronization of their buffers. They are a collection of sync_pts which may +or may not have the same timeline parent. A sync_pt can only exist in one fence +and the fence's list of sync_pts is immutable once created. Fences can be +waited on synchronously or asynchronously. Two fences can also be merged to +create a third fence containing a copy of the two fences’ sync_pts. Fences are +backed by file descriptors to allow userspace to coordinate the display pipeline +dependencies. + +Use: + +A driver implementing sync support should have a work submission function which: + * takes a fence argument specifying when to begin work + * asynchronously queues that work to kick off when the fence is signaled + * returns a fence to indicate when its work will be done. + * signals the returned fence once the work is completed. + +Consider an imaginary display driver that has the following API: +/* + * assumes buf is ready to be displayed. + * blocks until the buffer is on screen. + */ + void display_buffer(struct dma_buf *buf); + +The new API will become: +/* + * will display buf when fence is signaled. + * returns immediately with a fence that will signal when buf + * is no longer displayed. + */ +struct sync_fence* display_buffer(struct dma_buf *buf, + struct sync_fence *fence); diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index dcc75a9ed919..b81fca90f7fe 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -29,6 +29,7 @@ Currently, these files are in /proc/sys/vm: - dirty_writeback_centisecs - drop_caches - extfrag_threshold +- extra_free_kbytes - hugepages_treat_as_movable - hugetlb_shm_group - laptop_mode @@ -198,6 +199,21 @@ fragmentation index is <= extfrag_threshold. The default value is 500. ============================================================== +extra_free_kbytes + +This parameter tells the VM to keep extra free memory between the threshold +where background reclaim (kswapd) kicks in, and the threshold where direct +reclaim (by allocating processes) kicks in. + +This is useful for workloads that require low latency memory allocations +and have a bounded burstiness in memory allocations, for example a +realtime application that receives and transmits network traffic +(causing in-kernel memory allocations) with a maximum total message burst +size of 200MB may need 200MB of extra free memory to avoid direct reclaim +related latencies. + +============================================================== + hugepages_treat_as_movable This parameter is only useful when kernelcore= is specified at boot time to diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt index bfe8c29b1f1d..29064c3bfcd1 100644 --- a/Documentation/trace/ftrace.txt +++ b/Documentation/trace/ftrace.txt @@ -2013,6 +2013,35 @@ will produce: 1) 1.449 us | } +You can disable the hierarchical function call formatting and instead print a +flat list of function entry and return events. This uses the format described +in the Output Formatting section and respects all the trace options that +control that formatting. Hierarchical formatting is the default. + + hierachical: echo nofuncgraph-flat > trace_options + flat: echo funcgraph-flat > trace_options + + ie: + + # tracer: function_graph + # + # entries-in-buffer/entries-written: 68355/68355 #P:2 + # + # _-----=> irqs-off + # / _----=> need-resched + # | / _---=> hardirq/softirq + # || / _--=> preempt-depth + # ||| / delay + # TASK-PID CPU# |||| TIMESTAMP FUNCTION + # | | | |||| | | + sh-1806 [001] d... 198.843443: graph_ent: func=_raw_spin_lock + sh-1806 [001] d... 198.843445: graph_ent: func=__raw_spin_lock + sh-1806 [001] d..1 198.843447: graph_ret: func=__raw_spin_lock + sh-1806 [001] d..1 198.843449: graph_ret: func=_raw_spin_lock + sh-1806 [001] d..1 198.843451: graph_ent: func=_raw_spin_unlock_irqrestore + sh-1806 [001] d... 198.843453: graph_ret: func=_raw_spin_unlock_irqrestore + + You might find other useful features for this tracer in the following "dynamic ftrace" section such as tracing only specific functions or tasks. |