diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/CodingStyle | 3 | ||||
| -rw-r--r-- | Documentation/DocBook/kernel-locking.tmpl | 7 | ||||
| -rw-r--r-- | Documentation/accounting/getdelays.c | 4 | ||||
| -rw-r--r-- | Documentation/cgroups/memory.txt | 7 | ||||
| -rw-r--r-- | Documentation/crypto/async-tx-api.txt | 1 | ||||
| -rw-r--r-- | Documentation/devices.txt | 3 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/pps/pps-gpio.txt | 20 | ||||
| -rw-r--r-- | Documentation/filesystems/proc.txt | 7 | ||||
| -rw-r--r-- | Documentation/filesystems/vfs.txt | 25 | ||||
| -rw-r--r-- | Documentation/kdump/kdump.txt | 31 | ||||
| -rw-r--r-- | Documentation/rapidio/rapidio.txt | 98 | ||||
| -rw-r--r-- | Documentation/rapidio/sysfs.txt | 1 | ||||
| -rw-r--r-- | Documentation/rtc.txt | 7 | ||||
| -rw-r--r-- | Documentation/vm/pagemap.txt | 3 | ||||
| -rw-r--r-- | Documentation/vm/soft-dirty.txt | 36 |
15 files changed, 191 insertions, 62 deletions
diff --git a/Documentation/CodingStyle b/Documentation/CodingStyle index e00b8f0dde5..7fe0546c504 100644 --- a/Documentation/CodingStyle +++ b/Documentation/CodingStyle @@ -389,7 +389,8 @@ Albeit deprecated by some people, the equivalent of the goto statement is used frequently by compilers in form of the unconditional jump instruction. The goto statement comes in handy when a function exits from multiple -locations and some common work such as cleanup has to be done. +locations and some common work such as cleanup has to be done. If there is no +cleanup needed then just return directly. The rationale is: diff --git a/Documentation/DocBook/kernel-locking.tmpl b/Documentation/DocBook/kernel-locking.tmpl index 67e7ab41c0a..09e884e5b9f 100644 --- a/Documentation/DocBook/kernel-locking.tmpl +++ b/Documentation/DocBook/kernel-locking.tmpl @@ -1955,12 +1955,17 @@ machines due to caching. </sect1> </chapter> - <chapter id="apiref"> + <chapter id="apiref-mutex"> <title>Mutex API reference</title> !Iinclude/linux/mutex.h !Ekernel/mutex.c </chapter> + <chapter id="apiref-futex"> + <title>Futex API reference</title> +!Ikernel/futex.c + </chapter> + <chapter id="references"> <title>Further reading</title> diff --git a/Documentation/accounting/getdelays.c b/Documentation/accounting/getdelays.c index f8ebcde43b1..c6a06b71594 100644 --- a/Documentation/accounting/getdelays.c +++ b/Documentation/accounting/getdelays.c @@ -272,7 +272,7 @@ int main(int argc, char *argv[]) char *logfile = NULL; int loop = 0; int containerset = 0; - char containerpath[1024]; + char *containerpath = NULL; int cfd = 0; int forking = 0; sigset_t sigset; @@ -299,7 +299,7 @@ int main(int argc, char *argv[]) break; case 'C': containerset = 1; - strncpy(containerpath, optarg, strlen(optarg) + 1); + containerpath = optarg; break; case 'w': logfile = strdup(optarg); diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index ddf4f93967a..327acec6f90 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt @@ -834,10 +834,9 @@ Test: 12. TODO -1. Add support for accounting huge pages (as a separate controller) -2. Make per-cgroup scanner reclaim not-shared pages first -3. Teach controller to account for shared-pages -4. Start reclamation in the background when the limit is +1. Make per-cgroup scanner reclaim not-shared pages first +2. Teach controller to account for shared-pages +3. Start reclamation in the background when the limit is not yet hit but the usage is getting closer Summary diff --git a/Documentation/crypto/async-tx-api.txt b/Documentation/crypto/async-tx-api.txt index ba046b8fa92..7bf1be20d93 100644 --- a/Documentation/crypto/async-tx-api.txt +++ b/Documentation/crypto/async-tx-api.txt @@ -222,5 +222,4 @@ drivers/dma/: location for offload engine drivers include/linux/async_tx.h: core header file for the async_tx api crypto/async_tx/async_tx.c: async_tx interface to dmaengine and common code crypto/async_tx/async_memcpy.c: copy offload -crypto/async_tx/async_memset.c: memory fill offload crypto/async_tx/async_xor.c: xor and xor zero sum offload diff --git a/Documentation/devices.txt b/Documentation/devices.txt index b9015912bca..23721d3be3e 100644 --- a/Documentation/devices.txt +++ b/Documentation/devices.txt @@ -100,8 +100,7 @@ Your cooperation is appreciated. 10 = /dev/aio Asynchronous I/O notification interface 11 = /dev/kmsg Writes to this come out as printk's, reads export the buffered printk records. - 12 = /dev/oldmem Used by crashdump kernels to access - the memory of the kernel that crashed. + 12 = /dev/oldmem OBSOLETE - replaced by /proc/vmcore 1 block RAM disk 0 = /dev/ram0 First RAM disk diff --git a/Documentation/devicetree/bindings/pps/pps-gpio.txt b/Documentation/devicetree/bindings/pps/pps-gpio.txt new file mode 100644 index 00000000000..40bf9c3564a --- /dev/null +++ b/Documentation/devicetree/bindings/pps/pps-gpio.txt @@ -0,0 +1,20 @@ +Device-Tree Bindings for a PPS Signal on GPIO + +These properties describe a PPS (pulse-per-second) signal connected to +a GPIO pin. + +Required properties: +- compatible: should be "pps-gpio" +- gpios: one PPS GPIO in the format described by ../gpio/gpio.txt + +Optional properties: +- assert-falling-edge: when present, assert is indicated by a falling edge + (instead of by a rising edge) + +Example: + pps { + compatible = "pps-gpio"; + gpios = <&gpio2 6 0>; + + assert-falling-edge; + }; diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index fd8d0d594fc..fcc22c982a2 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -473,7 +473,8 @@ This file is only present if the CONFIG_MMU kernel configuration option is enabled. The /proc/PID/clear_refs is used to reset the PG_Referenced and ACCESSED/YOUNG -bits on both physical and virtual pages associated with a process. +bits on both physical and virtual pages associated with a process, and the +soft-dirty bit on pte (see Documentation/vm/soft-dirty.txt for details). To clear the bits for all the pages associated with the process > echo 1 > /proc/PID/clear_refs @@ -482,6 +483,10 @@ To clear the bits for the anonymous pages associated with the process To clear the bits for the file mapped pages associated with the process > echo 3 > /proc/PID/clear_refs + +To clear the soft-dirty bit + > echo 4 > /proc/PID/clear_refs + Any other value written to /proc/PID/clear_refs will have no effect. The /proc/pid/pagemap gives the PFN, which can be used to find the pageflags diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index 1f0ba30ae47..f93a88250a4 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -559,7 +559,6 @@ your filesystem. The following members are defined: struct address_space_operations { int (*writepage)(struct page *page, struct writeback_control *wbc); int (*readpage)(struct file *, struct page *); - int (*sync_page)(struct page *); int (*writepages)(struct address_space *, struct writeback_control *); int (*set_page_dirty)(struct page *page); int (*readpages)(struct file *filp, struct address_space *mapping, @@ -581,6 +580,9 @@ struct address_space_operations { /* migrate the contents of a page to the specified target */ int (*migratepage) (struct page *, struct page *); int (*launder_page) (struct page *); + int (*is_partially_uptodate) (struct page *, read_descriptor_t *, + unsigned long); + void (*is_dirty_writeback) (struct page *, bool *, bool *); int (*error_remove_page) (struct mapping *mapping, struct page *page); int (*swap_activate)(struct file *); int (*swap_deactivate)(struct file *); @@ -612,13 +614,6 @@ struct address_space_operations { In this case, the page will be relocated, relocked and if that all succeeds, ->readpage will be called again. - sync_page: called by the VM to notify the backing store to perform all - queued I/O operations for a page. I/O operations for other pages - associated with this address_space object may also be performed. - - This function is optional and is called only for pages with - PG_Writeback set while waiting for the writeback to complete. - writepages: called by the VM to write out pages associated with the address_space object. If wbc->sync_mode is WBC_SYNC_ALL, then the writeback_control will specify a range of pages that must be @@ -747,6 +742,20 @@ struct address_space_operations { prevent redirtying the page, it is kept locked during the whole operation. + is_partially_uptodate: Called by the VM when reading a file through the + pagecache when the underlying blocksize != pagesize. If the required + block is up to date then the read can complete without needing the IO + to bring the whole page up to date. + + is_dirty_writeback: Called by the VM when attempting to reclaim a page. + The VM uses dirty and writeback information to determine if it needs + to stall to allow flushers a chance to complete some IO. Ordinarily + it can use PageDirty and PageWriteback but some filesystems have + more complex state (unstable pages in NFS prevent reclaim) or + do not set those flags due to locking problems (jbd). This callback + allows a filesystem to indicate to the VM if a page should be + treated as dirty or writeback for the purposes of stalling. + error_remove_page: normally set to generic_error_remove_page if truncation is ok for this address space. Used for memory failure handling. Setting this implies you deal with pages going away under you, diff --git a/Documentation/kdump/kdump.txt b/Documentation/kdump/kdump.txt index 9c7fd988e29..bec123e466a 100644 --- a/Documentation/kdump/kdump.txt +++ b/Documentation/kdump/kdump.txt @@ -47,19 +47,12 @@ parameter. Optionally the size of the ELF header can also be passed when using the elfcorehdr=[size[KMG]@]offset[KMG] syntax. -With the dump-capture kernel, you can access the memory image, or "old -memory," in two ways: - -- Through a /dev/oldmem device interface. A capture utility can read the - device file and write out the memory in raw format. This is a raw dump - of memory. Analysis and capture tools must be intelligent enough to - determine where to look for the right information. - -- Through /proc/vmcore. This exports the dump as an ELF-format file that - you can write out using file copy commands such as cp or scp. Further, - you can use analysis tools such as the GNU Debugger (GDB) and the Crash - tool to debug the dump file. This method ensures that the dump pages are - correctly ordered. +With the dump-capture kernel, you can access the memory image through +/proc/vmcore. This exports the dump as an ELF-format file that you can +write out using file copy commands such as cp or scp. Further, you can +use analysis tools such as the GNU Debugger (GDB) and the Crash tool to +debug the dump file. This method ensures that the dump pages are correctly +ordered. Setup and Installation @@ -423,18 +416,6 @@ the following command: cp /proc/vmcore <dump-file> -You can also access dumped memory as a /dev/oldmem device for a linear -and raw view. To create the device, use the following command: - - mknod /dev/oldmem c 1 12 - -Use the dd command with suitable options for count, bs, and skip to -access specific portions of the dump. - -To see the entire memory, use the following command: - - dd if=/dev/oldmem of=oldmem.001 - Analysis ======== diff --git a/Documentation/rapidio/rapidio.txt b/Documentation/rapidio/rapidio.txt index a9c16c979da..717f5aa388b 100644 --- a/Documentation/rapidio/rapidio.txt +++ b/Documentation/rapidio/rapidio.txt @@ -73,28 +73,44 @@ data structure. This structure includes lists of all devices and local master ports that form the same network. It also contains a pointer to the default master port that is used to communicate with devices within the network. +2.5 Device Drivers + +RapidIO device-specific drivers follow Linux Kernel Driver Model and are +intended to support specific RapidIO devices attached to the RapidIO network. + +2.6 Subsystem Interfaces + +RapidIO interconnect specification defines features that may be used to provide +one or more common service layers for all participating RapidIO devices. These +common services may act separately from device-specific drivers or be used by +device-specific drivers. Example of such service provider is the RIONET driver +which implements Ethernet-over-RapidIO interface. Because only one driver can be +registered for a device, all common RapidIO services have to be registered as +subsystem interfaces. This allows to have multiple common services attached to +the same device without blocking attachment of a device-specific driver. + 3. Subsystem Initialization --------------------------- In order to initialize the RapidIO subsystem, a platform must initialize and register at least one master port within the RapidIO network. To register mport -within the subsystem controller driver initialization code calls function +within the subsystem controller driver's initialization code calls function rio_register_mport() for each available master port. -RapidIO subsystem uses subsys_initcall() or device_initcall() to perform -controller initialization (depending on controller device type). - After all active master ports are registered with a RapidIO subsystem, an enumeration and/or discovery routine may be called automatically or by user-space command. +RapidIO subsystem can be configured to be built as a statically linked or +modular component of the kernel (see details below). + 4. Enumeration and Discovery ---------------------------- 4.1 Overview ------------ -RapidIO subsystem configuration options allow users to specify enumeration and +RapidIO subsystem configuration options allow users to build enumeration and discovery methods as statically linked components or loadable modules. An enumeration/discovery method implementation and available input parameters define how any given method can be attached to available RapidIO mports: @@ -115,8 +131,8 @@ several methods to initiate an enumeration and/or discovery process: endpoint waits for enumeration to be completed. If the specified timeout expires the discovery process is terminated without obtaining RapidIO network information. NOTE: a timed out discovery process may be restarted later using - a user-space command as it is described later if the given endpoint was - enumerated successfully. + a user-space command as it is described below (if the given endpoint was + enumerated successfully). (b) Statically linked enumeration and discovery process can be started by a command from user space. This initiation method provides more flexibility @@ -138,15 +154,42 @@ When a network scan process is started it calls an enumeration or discovery routine depending on the configured role of a master port: host or agent. Enumeration is performed by a master port if it is configured as a host port by -assigning a host device ID greater than or equal to zero. A host device ID is -assigned to a master port through the kernel command line parameter "riohdid=", -or can be configured in a platform-specific manner. If the host device ID for -a specific master port is set to -1, the discovery process will be performed -for it. +assigning a host destination ID greater than or equal to zero. The host +destination ID can be assigned to a master port using various methods depending +on RapidIO subsystem build configuration: + + (a) For a statically linked RapidIO subsystem core use command line parameter + "rapidio.hdid=" with a list of destination ID assignments in order of mport + device registration. For example, in a system with two RapidIO controllers + the command line parameter "rapidio.hdid=-1,7" will result in assignment of + the host destination ID=7 to the second RapidIO controller, while the first + one will be assigned destination ID=-1. + + (b) If the RapidIO subsystem core is built as a loadable module, in addition + to the method shown above, the host destination ID(s) can be specified using + traditional methods of passing module parameter "hdid=" during its loading: + - from command line: "modprobe rapidio hdid=-1,7", or + - from modprobe configuration file using configuration command "options", + like in this example: "options rapidio hdid=-1,7". An example of modprobe + configuration file is provided in the section below. + + NOTES: + (i) if "hdid=" parameter is omitted all available mport will be assigned + destination ID = -1; + (ii) the "hdid=" parameter in systems with multiple mports can have + destination ID assignments omitted from the end of list (default = -1). + +If the host device ID for a specific master port is set to -1, the discovery +process will be performed for it. The enumeration and discovery routines use RapidIO maintenance transactions to access the configuration space of devices. +NOTE: If RapidIO switch-specific device drivers are built as loadable modules +they must be loaded before enumeration/discovery process starts. +This requirement is cased by the fact that enumeration/discovery methods invoke +vendor-specific callbacks on early stages. + 4.2 Automatic Start of Enumeration and Discovery ------------------------------------------------ @@ -266,7 +309,36 @@ method's module initialization routine calls rio_register_scan() to attach an enumerator to a specified mport device (or devices). The basic enumerator implementation demonstrates this process. -5. References +4.6 Using Loadable RapidIO Switch Drivers +----------------------------------------- + +In the case when RapidIO switch drivers are built as loadable modules a user +must ensure that they are loaded before the enumeration/discovery starts. +This process can be automated by specifying pre- or post- dependencies in the +RapidIO-specific modprobe configuration file as shown in the example below. + + File /etc/modprobe.d/rapidio.conf: + ---------------------------------- + + # Configure RapidIO subsystem modules + + # Set enumerator host destination ID (overrides kernel command line option) + options rapidio hdid=-1,2 + + # Load RapidIO switch drivers immediately after rapidio core module was loaded + softdep rapidio post: idt_gen2 idtcps tsi57x + + # OR : + + # Load RapidIO switch drivers just before rio-scan enumerator module is loaded + softdep rio-scan pre: idt_gen2 idtcps tsi57x + + -------------------------- + +NOTE: In the example above, one of "softdep" commands must be removed or +commented out to keep required module loading sequence. + +A. References ------------- [1] RapidIO Trade Association. RapidIO Interconnect Specifications. diff --git a/Documentation/rapidio/sysfs.txt b/Documentation/rapidio/sysfs.txt index 19878179da4..271438c0617 100644 --- a/Documentation/rapidio/sysfs.txt +++ b/Documentation/rapidio/sysfs.txt @@ -40,6 +40,7 @@ device_rev - returns the device revision level (see 4.1 for switch specific details) lprev - returns name of previous device (switch) on the path to the device that that owns this attribute + modalias - returns the device modalias In addition to the files listed above, each device has a binary attribute file that allows read/write access to the device configuration registers using diff --git a/Documentation/rtc.txt b/Documentation/rtc.txt index 32aa4002de4..596b60c08b7 100644 --- a/Documentation/rtc.txt +++ b/Documentation/rtc.txt @@ -153,9 +153,10 @@ since_epoch: The number of seconds since the epoch according to the RTC time: RTC-provided time wakealarm: The time at which the clock will generate a system wakeup event. This is a one shot wakeup event, so must be reset - after wake if a daily wakeup is required. Format is either - seconds since the epoch or, if there's a leading +, seconds - in the future. + after wake if a daily wakeup is required. Format is seconds since + the epoch by default, or if there's a leading +, seconds in the + future, or if there is a leading +=, seconds ahead of the current + alarm. IOCTL INTERFACE --------------- diff --git a/Documentation/vm/pagemap.txt b/Documentation/vm/pagemap.txt index 7587493c67f..fd7c3cfddd8 100644 --- a/Documentation/vm/pagemap.txt +++ b/Documentation/vm/pagemap.txt @@ -15,7 +15,8 @@ There are three components to pagemap: * Bits 0-54 page frame number (PFN) if present * Bits 0-4 swap type if swapped * Bits 5-54 swap offset if swapped - * Bits 55-60 page shift (page size = 1<<page shift) + * Bit 55 pte is soft-dirty (see Documentation/vm/soft-dirty.txt) + * Bits 56-60 zero * Bit 61 page is file-page or shared-anon * Bit 62 page swapped * Bit 63 page present diff --git a/Documentation/vm/soft-dirty.txt b/Documentation/vm/soft-dirty.txt new file mode 100644 index 00000000000..9a12a5956bc --- /dev/null +++ b/Documentation/vm/soft-dirty.txt @@ -0,0 +1,36 @@ + SOFT-DIRTY PTEs + + The soft-dirty is a bit on a PTE which helps to track which pages a task +writes to. In order to do this tracking one should + + 1. Clear soft-dirty bits from the task's PTEs. + + This is done by writing "4" into the /proc/PID/clear_refs file of the + task in question. + + 2. Wait some time. + + 3. Read soft-dirty bits from the PTEs. + + This is done by reading from the /proc/PID/pagemap. The bit 55 of the + 64-bit qword is the soft-dirty one. If set, the respective PTE was + written to since step 1. + + + Internally, to do this tracking, the writable bit is cleared from PTEs +when the soft-dirty bit is cleared. So, after this, when the task tries to +modify a page at some virtual address the #PF occurs and the kernel sets +the soft-dirty bit on the respective PTE. + + Note, that although all the task's address space is marked as r/o after the +soft-dirty bits clear, the #PF-s that occur after that are processed fast. +This is so, since the pages are still mapped to physical memory, and thus all +the kernel does is finds this fact out and puts both writable and soft-dirty +bits on the PTE. + + + This feature is actively used by the checkpoint-restore project. You +can find more details about it on http://criu.org + + +-- Pavel Emelyanov, Apr 9, 2013 |