diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-backlight-driver-lm3533 | 48 | ||||
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-led-driver-lm3533 | 65 | ||||
| -rw-r--r-- | Documentation/cgroups/memory.txt | 37 | ||||
| -rw-r--r-- | Documentation/cgroups/resource_counter.txt | 8 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/rtc/lpc32xx-rtc.txt | 15 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/rtc/spear-rtc.txt | 17 | ||||
| -rw-r--r-- | Documentation/filesystems/Locking | 2 | ||||
| -rw-r--r-- | Documentation/filesystems/proc.txt | 2 | ||||
| -rw-r--r-- | Documentation/filesystems/vfs.txt | 13 | ||||
| -rw-r--r-- | Documentation/leds/ledtrig-transient.txt | 152 | ||||
| -rw-r--r-- | Documentation/vm/transhuge.txt | 62 |
11 files changed, 393 insertions, 28 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-backlight-driver-lm3533 b/Documentation/ABI/testing/sysfs-class-backlight-driver-lm3533 new file mode 100644 index 000000000000..77cf7ac949af --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-backlight-driver-lm3533 @@ -0,0 +1,48 @@ +What: /sys/class/backlight/<backlight>/als_channel +Date: May 2012 +KernelVersion: 3.5 +Contact: Johan Hovold <jhovold@gmail.com> +Description: + Get the ALS output channel used as input in + ALS-current-control mode (0, 1), where + + 0 - out_current0 (backlight 0) + 1 - out_current1 (backlight 1) + +What: /sys/class/backlight/<backlight>/als_en +Date: May 2012 +KernelVersion: 3.5 +Contact: Johan Hovold <jhovold@gmail.com> +Description: + Enable ALS-current-control mode (0, 1). + +What: /sys/class/backlight/<backlight>/id +Date: April 2012 +KernelVersion: 3.5 +Contact: Johan Hovold <jhovold@gmail.com> +Description: + Get the id of this backlight (0, 1). + +What: /sys/class/backlight/<backlight>/linear +Date: April 2012 +KernelVersion: 3.5 +Contact: Johan Hovold <jhovold@gmail.com> +Description: + Set the brightness-mapping mode (0, 1), where + + 0 - exponential mode + 1 - linear mode + +What: /sys/class/backlight/<backlight>/pwm +Date: April 2012 +KernelVersion: 3.5 +Contact: Johan Hovold <jhovold@gmail.com> +Description: + Set the PWM-input control mask (5 bits), where + + bit 5 - PWM-input enabled in Zone 4 + bit 4 - PWM-input enabled in Zone 3 + bit 3 - PWM-input enabled in Zone 2 + bit 2 - PWM-input enabled in Zone 1 + bit 1 - PWM-input enabled in Zone 0 + bit 0 - PWM-input enabled diff --git a/Documentation/ABI/testing/sysfs-class-led-driver-lm3533 b/Documentation/ABI/testing/sysfs-class-led-driver-lm3533 new file mode 100644 index 000000000000..620ebb3b9baa --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-led-driver-lm3533 @@ -0,0 +1,65 @@ +What: /sys/class/leds/<led>/als_channel +Date: May 2012 +KernelVersion: 3.5 +Contact: Johan Hovold <jhovold@gmail.com> +Description: + Set the ALS output channel to use as input in + ALS-current-control mode (1, 2), where + + 1 - out_current1 + 2 - out_current2 + +What: /sys/class/leds/<led>/als_en +Date: May 2012 +KernelVersion: 3.5 +Contact: Johan Hovold <jhovold@gmail.com> +Description: + Enable ALS-current-control mode (0, 1). + +What: /sys/class/leds/<led>/falltime +What: /sys/class/leds/<led>/risetime +Date: April 2012 +KernelVersion: 3.5 +Contact: Johan Hovold <jhovold@gmail.com> +Description: + Set the pattern generator fall and rise times (0..7), where + + 0 - 2048 us + 1 - 262 ms + 2 - 524 ms + 3 - 1.049 s + 4 - 2.097 s + 5 - 4.194 s + 6 - 8.389 s + 7 - 16.78 s + +What: /sys/class/leds/<led>/id +Date: April 2012 +KernelVersion: 3.5 +Contact: Johan Hovold <jhovold@gmail.com> +Description: + Get the id of this led (0..3). + +What: /sys/class/leds/<led>/linear +Date: April 2012 +KernelVersion: 3.5 +Contact: Johan Hovold <jhovold@gmail.com> +Description: + Set the brightness-mapping mode (0, 1), where + + 0 - exponential mode + 1 - linear mode + +What: /sys/class/leds/<led>/pwm +Date: April 2012 +KernelVersion: 3.5 +Contact: Johan Hovold <jhovold@gmail.com> +Description: + Set the PWM-input control mask (5 bits), where + + bit 5 - PWM-input enabled in Zone 4 + bit 4 - PWM-input enabled in Zone 3 + bit 3 - PWM-input enabled in Zone 2 + bit 2 - PWM-input enabled in Zone 1 + bit 1 - PWM-input enabled in Zone 0 + bit 0 - PWM-input enabled diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index 9b1067afb224..dd88540bb995 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt @@ -184,12 +184,14 @@ behind this approach is that a cgroup that aggressively uses a shared page will eventually get charged for it (once it is uncharged from the cgroup that brought it in -- this will happen on memory pressure). +But see section 8.2: when moving a task to another cgroup, its pages may +be recharged to the new cgroup, if move_charge_at_immigrate has been chosen. + Exception: If CONFIG_CGROUP_CGROUP_MEM_RES_CTLR_SWAP is not used. When you do swapoff and make swapped-out pages of shmem(tmpfs) to be backed into memory in force, charges for pages are accounted against the caller of swapoff rather than the users of shmem. - 2.4 Swap Extension (CONFIG_CGROUP_MEM_RES_CTLR_SWAP) Swap Extension allows you to record charge for swap. A swapped-in page is @@ -374,14 +376,15 @@ cgroup might have some charge associated with it, even though all tasks have migrated away from it. (because we charge against pages, not against tasks.) -Such charges are freed or moved to their parent. At moving, both of RSS -and CACHES are moved to parent. -rmdir() may return -EBUSY if freeing/moving fails. See 5.1 also. +We move the stats to root (if use_hierarchy==0) or parent (if +use_hierarchy==1), and no change on the charge except uncharging +from the child. Charges recorded in swap information is not updated at removal of cgroup. Recorded information is discarded and a cgroup which uses swap (swapcache) will be charged as a new owner of it. +About use_hierarchy, see Section 6. 5. Misc. interfaces. @@ -394,13 +397,15 @@ will be charged as a new owner of it. Almost all pages tracked by this memory cgroup will be unmapped and freed. Some pages cannot be freed because they are locked or in-use. Such pages are - moved to parent and this cgroup will be empty. This may return -EBUSY if - VM is too busy to free/move all pages immediately. + moved to parent(if use_hierarchy==1) or root (if use_hierarchy==0) and this + cgroup will be empty. Typical use case of this interface is that calling this before rmdir(). Because rmdir() moves all pages to parent, some out-of-use page caches can be moved to the parent. If you want to avoid that, force_empty will be useful. + About use_hierarchy, see Section 6. + 5.2 stat file memory.stat file includes following statistics @@ -430,17 +435,10 @@ hierarchical_memory_limit - # of bytes of memory limit with regard to hierarchy hierarchical_memsw_limit - # of bytes of memory+swap limit with regard to hierarchy under which memory cgroup is. -total_cache - sum of all children's "cache" -total_rss - sum of all children's "rss" -total_mapped_file - sum of all children's "cache" -total_pgpgin - sum of all children's "pgpgin" -total_pgpgout - sum of all children's "pgpgout" -total_swap - sum of all children's "swap" -total_inactive_anon - sum of all children's "inactive_anon" -total_active_anon - sum of all children's "active_anon" -total_inactive_file - sum of all children's "inactive_file" -total_active_file - sum of all children's "active_file" -total_unevictable - sum of all children's "unevictable" +total_<counter> - # hierarchical version of <counter>, which in + addition to the cgroup's own value includes the + sum of all hierarchical children's values of + <counter>, i.e. total_cache # The following additional stats are dependent on CONFIG_DEBUG_VM. @@ -622,8 +620,7 @@ memory cgroup. bit | what type of charges would be moved ? -----+------------------------------------------------------------------------ 0 | A charge of an anonymous page(or swap of it) used by the target task. - | Those pages and swaps must be used only by the target task. You must - | enable Swap Extension(see 2.4) to enable move of swap charges. + | You must enable Swap Extension(see 2.4) to enable move of swap charges. -----+------------------------------------------------------------------------ 1 | A charge of file pages(normal file, tmpfs file(e.g. ipc shared memory) | and swaps of tmpfs file) mmapped by the target task. Unlike the case of @@ -636,8 +633,6 @@ memory cgroup. 8.3 TODO -- Implement madvise(2) to let users decide the vma to be moved or not to be - moved. - All of moving charge operations are done under cgroup_mutex. It's not good behavior to hold the mutex too long, so we may need some trick. diff --git a/Documentation/cgroups/resource_counter.txt b/Documentation/cgroups/resource_counter.txt index f3c4ec3626a2..0c4a344e78fa 100644 --- a/Documentation/cgroups/resource_counter.txt +++ b/Documentation/cgroups/resource_counter.txt @@ -92,6 +92,14 @@ to work with it. The _locked routines imply that the res_counter->lock is taken. + f. void res_counter_uncharge_until + (struct res_counter *rc, struct res_counter *top, + unsinged long val) + + Almost same as res_cunter_uncharge() but propagation of uncharge + stops when rc == top. This is useful when kill a res_coutner in + child cgroup. + 2.1 Other accounting routines There are more routines that may help you with common needs, like diff --git a/Documentation/devicetree/bindings/rtc/lpc32xx-rtc.txt b/Documentation/devicetree/bindings/rtc/lpc32xx-rtc.txt new file mode 100644 index 000000000000..a87a1e9bc060 --- /dev/null +++ b/Documentation/devicetree/bindings/rtc/lpc32xx-rtc.txt @@ -0,0 +1,15 @@ +* NXP LPC32xx SoC Real Time Clock controller + +Required properties: +- compatible: must be "nxp,lpc3220-rtc" +- reg: physical base address of the controller and length of memory mapped + region. +- interrupts: The RTC interrupt + +Example: + + rtc@40024000 { + compatible = "nxp,lpc3220-rtc"; + reg = <0x40024000 0x1000>; + interrupts = <52 0>; + }; diff --git a/Documentation/devicetree/bindings/rtc/spear-rtc.txt b/Documentation/devicetree/bindings/rtc/spear-rtc.txt new file mode 100644 index 000000000000..ca67ac62108e --- /dev/null +++ b/Documentation/devicetree/bindings/rtc/spear-rtc.txt @@ -0,0 +1,17 @@ +* SPEAr RTC + +Required properties: +- compatible : "st,spear600-rtc" +- reg : Address range of the rtc registers +- interrupt-parent: Should be the phandle for the interrupt controller + that services interrupts for this device +- interrupt: Should contain the rtc interrupt number + +Example: + + rtc@fc000000 { + compatible = "st,spear600-rtc"; + reg = <0xfc000000 0x1000>; + interrupt-parent = <&vic1>; + interrupts = <12>; + }; diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index 4fca82e5276e..d449e632e6a0 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -60,7 +60,6 @@ ata *); ssize_t (*getxattr) (struct dentry *, const char *, void *, size_t); ssize_t (*listxattr) (struct dentry *, char *, size_t); int (*removexattr) (struct dentry *, const char *); - void (*truncate_range)(struct inode *, loff_t, loff_t); int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start, u64 len); locking rules: @@ -87,7 +86,6 @@ setxattr: yes getxattr: no listxattr: no removexattr: yes -truncate_range: yes fiemap: no Additionally, ->rmdir(), ->unlink() and ->rename() have ->i_mutex on victim. diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index ef088e55ab2e..912af6ce5626 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -743,6 +743,7 @@ Committed_AS: 100056 kB VmallocTotal: 112216 kB VmallocUsed: 428 kB VmallocChunk: 111088 kB +AnonHugePages: 49152 kB MemTotal: Total usable ram (i.e. physical ram minus a few reserved bits and the kernel binary code) @@ -776,6 +777,7 @@ VmallocChunk: 111088 kB Dirty: Memory which is waiting to get written back to the disk Writeback: Memory which is actively being written back to the disk AnonPages: Non-file backed pages mapped into userspace page tables +AnonHugePages: Non-file backed huge pages mapped into userspace page tables Mapped: files which have been mmaped, such as libraries Slab: in-kernel data structures cache SReclaimable: Part of Slab, that might be reclaimed, such as caches diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index 0d0492028082..ef19f91a0f12 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -363,7 +363,6 @@ struct inode_operations { ssize_t (*getxattr) (struct dentry *, const char *, void *, size_t); ssize_t (*listxattr) (struct dentry *, char *, size_t); int (*removexattr) (struct dentry *, const char *); - void (*truncate_range)(struct inode *, loff_t, loff_t); }; Again, all methods are called without any locks being held, unless @@ -472,9 +471,6 @@ otherwise noted. removexattr: called by the VFS to remove an extended attribute from a file. This method is called by removexattr(2) system call. - truncate_range: a method provided by the underlying filesystem to truncate a - range of blocks , i.e. punch a hole somewhere in a file. - The Address Space Object ======================== @@ -760,7 +756,7 @@ struct file_operations ---------------------- This describes how the VFS can manipulate an open file. As of kernel -2.6.22, the following members are defined: +3.5, the following members are defined: struct file_operations { struct module *owner; @@ -790,6 +786,8 @@ struct file_operations { int (*flock) (struct file *, int, struct file_lock *); ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, size_t, unsigned int); ssize_t (*splice_read)(struct file *, struct pipe_inode_info *, size_t, unsigned int); + int (*setlease)(struct file *, long arg, struct file_lock **); + long (*fallocate)(struct file *, int mode, loff_t offset, loff_t len); }; Again, all methods are called without any locks being held, unless @@ -858,6 +856,11 @@ otherwise noted. splice_read: called by the VFS to splice data from file to a pipe. This method is used by the splice(2) system call + setlease: called by the VFS to set or release a file lock lease. + setlease has the file_lock_lock held and must not sleep. + + fallocate: called by the VFS to preallocate blocks or punch a hole. + Note that the file operations are implemented by the specific filesystem in which the inode resides. When opening a device node (character or block special) most filesystems will call special diff --git a/Documentation/leds/ledtrig-transient.txt b/Documentation/leds/ledtrig-transient.txt new file mode 100644 index 000000000000..3bd38b487df1 --- /dev/null +++ b/Documentation/leds/ledtrig-transient.txt @@ -0,0 +1,152 @@ +LED Transient Trigger +===================== + +The leds timer trigger does not currently have an interface to activate +a one shot timer. The current support allows for setting two timers, one for +specifying how long a state to be on, and the second for how long the state +to be off. The delay_on value specifies the time period an LED should stay +in on state, followed by a delay_off value that specifies how long the LED +should stay in off state. The on and off cycle repeats until the trigger +gets deactivated. There is no provision for one time activation to implement +features that require an on or off state to be held just once and then stay in +the original state forever. + +Without one shot timer interface, user space can still use timer trigger to +set a timer to hold a state, however when user space application crashes or +goes away without deactivating the timer, the hardware will be left in that +state permanently. + +As a specific example of this use-case, let's look at vibrate feature on +phones. Vibrate function on phones is implemented using PWM pins on SoC or +PMIC. There is a need to activate one shot timer to control the vibrate +feature, to prevent user space crashes leaving the phone in vibrate mode +permanently causing the battery to drain. + +Transient trigger addresses the need for one shot timer activation. The +transient trigger can be enabled and disabled just like the other leds +triggers. + +When an led class device driver registers itself, it can specify all leds +triggers it supports and a default trigger. During registration, activation +routine for the default trigger gets called. During registration of an led +class device, the LED state does not change. + +When the driver unregisters, deactivation routine for the currently active +trigger will be called, and LED state is changed to LED_OFF. + +Driver suspend changes the LED state to LED_OFF and resume doesn't change +the state. Please note that there is no explicit interaction between the +suspend and resume actions and the currently enabled trigger. LED state +changes are suspended while the driver is in suspend state. Any timers +that are active at the time driver gets suspended, continue to run, without +being able to actually change the LED state. Once driver is resumed, triggers +start functioning again. + +LED state changes are controlled using brightness which is a common led +class device property. When brightness is set to 0 from user space via +echo 0 > brightness, it will result in deactivating the current trigger. + +Transient trigger uses standard register and unregister interfaces. During +trigger registration, for each led class device that specifies this trigger +as its default trigger, trigger activation routine will get called. During +registration, the LED state does not change, unless there is another trigger +active, in which case LED state changes to LED_OFF. + +During trigger unregistration, LED state gets changed to LED_OFF. + +Transient trigger activation routine doesn't change the LED state. It +creates its properties and does its initialization. Transient trigger +deactivation routine, will cancel any timer that is active before it cleans +up and removes the properties it created. It will restore the LED state to +non-transient state. When driver gets suspended, irrespective of the transient +state, the LED state changes to LED_OFF. + +Transient trigger can be enabled and disabled from user space on led class +devices, that support this trigger as shown below: + +echo transient > trigger +echo none > trigger + +NOTE: Add a new property trigger state to control the state. + +This trigger exports three properties, activate, state, and duration. When +transient trigger is activated these properties are set to default values. + +- duration allows setting timer value in msecs. The initial value is 0. +- activate allows activating and deactivating the timer specified by + duration as needed. The initial and default value is 0. This will allow + duration to be set after trigger activation. +- state allows user to specify a transient state to be held for the specified + duration. + + activate - one shot timer activate mechanism. + 1 when activated, 0 when deactivated. + default value is zero when transient trigger is enabled, + to allow duration to be set. + + activate state indicates a timer with a value of specified + duration running. + deactivated state indicates that there is no active timer + running. + + duration - one shot timer value. When activate is set, duration value + is used to start a timer that runs once. This value doesn't + get changed by the trigger unless user does a set via + echo new_value > duration + + state - transient state to be held. It has two values 0 or 1. 0 maps + to LED_OFF and 1 maps to LED_FULL. The specified state is + held for the duration of the one shot timer and then the + state gets changed to the non-transient state which is the + inverse of transient state. + If state = LED_FULL, when the timer runs out the state will + go back to LED_OFF. + If state = LED_OFF, when the timer runs out the state will + go back to LED_FULL. + Please note that current LED state is not checked prior to + changing the state to the specified state. + Driver could map these values to inverted depending on the + default states it defines for the LED in its brightness_set() + interface which is called from the led brightness_set() + interfaces to control the LED state. + +When timer expires activate goes back to deactivated state, duration is left +at the set value to be used when activate is set at a future time. This will +allow user app to set the time once and activate it to run it once for the +specified value as needed. When timer expires, state is restored to the +non-transient state which is the inverse of the transient state. + + echo 1 > activate - starts timer = duration when duration is not 0. + echo 0 > activate - cancels currently running timer. + echo n > duration - stores timer value to be used upon next + activate. Currently active timer if + any, continues to run for the specified time. + echo 0 > duration - stores timer value to be used upon next + activate. Currently active timer if any, + continues to run for the specified time. + echo 1 > state - stores desired transient state LED_FULL to be + held for the specified duration. + echo 0 > state - stores desired transient state LED_OFF to be + held for the specified duration. + +What is not supported: +====================== +- Timer activation is one shot and extending and/or shortening the timer + is not supported. + +Example use-case 1: + echo transient > trigger + echo n > duration + echo 1 > state +repeat the following step as needed: + echo 1 > activate - start timer = duration to run once + echo 1 > activate - start timer = duration to run once + echo none > trigger + +This trigger is intended to be used for for the following example use cases: + - Control of vibrate (phones, tablets etc.) hardware by user space app. + - Use of LED by user space app as activity indicator. + - Use of LED by user space app as a kind of watchdog indicator -- as + long as the app is alive, it can keep the LED illuminated, if it dies + the LED will be extinguished automatically. + - Use by any user space app that needs a transient GPIO output. diff --git a/Documentation/vm/transhuge.txt b/Documentation/vm/transhuge.txt index 29bdf62aac09..f734bb2a78dc 100644 --- a/Documentation/vm/transhuge.txt +++ b/Documentation/vm/transhuge.txt @@ -166,6 +166,68 @@ behavior. So to make them effective you need to restart any application that could have been using hugepages. This also applies to the regions registered in khugepaged. +== Monitoring usage == + +The number of transparent huge pages currently used by the system is +available by reading the AnonHugePages field in /proc/meminfo. To +identify what applications are using transparent huge pages, it is +necessary to read /proc/PID/smaps and count the AnonHugePages fields +for each mapping. Note that reading the smaps file is expensive and +reading it frequently will incur overhead. + +There are a number of counters in /proc/vmstat that may be used to +monitor how successfully the system is providing huge pages for use. + +thp_fault_alloc is incremented every time a huge page is successfully + allocated to handle a page fault. This applies to both the + first time a page is faulted and for COW faults. + +thp_collapse_alloc is incremented by khugepaged when it has found + a range of pages to collapse into one huge page and has + successfully allocated a new huge page to store the data. + +thp_fault_fallback is incremented if a page fault fails to allocate + a huge page and instead falls back to using small pages. + +thp_collapse_alloc_failed is incremented if khugepaged found a range + of pages that should be collapsed into one huge page but failed + the allocation. + +thp_split is incremented every time a huge page is split into base + pages. This can happen for a variety of reasons but a common + reason is that a huge page is old and is being reclaimed. + +As the system ages, allocating huge pages may be expensive as the +system uses memory compaction to copy data around memory to free a +huge page for use. There are some counters in /proc/vmstat to help +monitor this overhead. + +compact_stall is incremented every time a process stalls to run + memory compaction so that a huge page is free for use. + +compact_success is incremented if the system compacted memory and + freed a huge page for use. + +compact_fail is incremented if the system tries to compact memory + but failed. + +compact_pages_moved is incremented each time a page is moved. If + this value is increasing rapidly, it implies that the system + is copying a lot of data to satisfy the huge page allocation. + It is possible that the cost of copying exceeds any savings + from reduced TLB misses. + +compact_pagemigrate_failed is incremented when the underlying mechanism + for moving a page failed. + +compact_blocks_moved is incremented each time memory compaction examines + a huge page aligned range of pages. + +It is possible to establish how long the stalls were using the function +tracer to record how long was spent in __alloc_pages_nodemask and +using the mm_page_alloc tracepoint to identify which allocations were +for huge pages. + == get_user_pages and follow_page == get_user_pages and follow_page if run on a hugepage, will return the |