diff options
Diffstat (limited to 'Documentation')
26 files changed, 1493 insertions, 184 deletions
diff --git a/Documentation/ABI/stable/sysfs-devices-node b/Documentation/ABI/stable/sysfs-devices-node new file mode 100644 index 00000000000..49b82cad700 --- /dev/null +++ b/Documentation/ABI/stable/sysfs-devices-node @@ -0,0 +1,7 @@ +What: /sys/devices/system/node/nodeX +Date: October 2002 +Contact: Linux Memory Management list <linux-mm@kvack.org> +Description: + When CONFIG_NUMA is enabled, this is a directory containing + information on node X such as what CPUs are local to the + node. diff --git a/Documentation/cdrom/ide-cd b/Documentation/cdrom/ide-cd index 2c558cd6c1e..f4dc9de2694 100644 --- a/Documentation/cdrom/ide-cd +++ b/Documentation/cdrom/ide-cd @@ -159,42 +159,7 @@ two arguments: the CDROM device, and the slot number to which you wish to change. If the slot number is -1, the drive is unloaded. -4. Compilation options ----------------------- - -There are a few additional options which can be set when compiling the -driver. Most people should not need to mess with any of these; they -are listed here simply for completeness. A compilation option can be -enabled by adding a line of the form `#define <option> 1' to the top -of ide-cd.c. All these options are disabled by default. - -VERBOSE_IDE_CD_ERRORS - If this is set, ATAPI error codes will be translated into textual - descriptions. In addition, a dump is made of the command which - provoked the error. This is off by default to save the memory used - by the (somewhat long) table of error descriptions. - -STANDARD_ATAPI - If this is set, the code needed to deal with certain drives which do - not properly implement the ATAPI spec will be disabled. If you know - your drive implements ATAPI properly, you can turn this on to get a - slightly smaller kernel. - -NO_DOOR_LOCKING - If this is set, the driver will never attempt to lock the door of - the drive. - -CDROM_NBLOCKS_BUFFER - This sets the size of the buffer to be used for a CDROMREADAUDIO - ioctl. The default is 8. - -TEST - This currently enables an additional ioctl which enables a user-mode - program to execute an arbitrary packet command. See the source for - details. This should be left off unless you know what you're doing. - - -5. Common problems +4. Common problems ------------------ This section discusses some common problems encountered when trying to @@ -371,7 +336,7 @@ f. Data corruption. expense of low system performance. -6. cdchange.c +5. cdchange.c ------------- /* diff --git a/Documentation/cpu-freq/pcc-cpufreq.txt b/Documentation/cpu-freq/pcc-cpufreq.txt new file mode 100644 index 00000000000..9e3c3b33514 --- /dev/null +++ b/Documentation/cpu-freq/pcc-cpufreq.txt @@ -0,0 +1,207 @@ +/* + * pcc-cpufreq.txt - PCC interface documentation + * + * Copyright (C) 2009 Red Hat, Matthew Garrett <mjg@redhat.com> + * Copyright (C) 2009 Hewlett-Packard Development Company, L.P. + * Nagananda Chumbalkar <nagananda.chumbalkar@hp.com> + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or NON + * INFRINGEMENT. See the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 675 Mass Ave, Cambridge, MA 02139, USA. + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + */ + + + Processor Clocking Control Driver + --------------------------------- + +Contents: +--------- +1. Introduction +1.1 PCC interface +1.1.1 Get Average Frequency +1.1.2 Set Desired Frequency +1.2 Platforms affected +2. Driver and /sys details +2.1 scaling_available_frequencies +2.2 cpuinfo_transition_latency +2.3 cpuinfo_cur_freq +2.4 related_cpus +3. Caveats + +1. Introduction: +---------------- +Processor Clocking Control (PCC) is an interface between the platform +firmware and OSPM. It is a mechanism for coordinating processor +performance (ie: frequency) between the platform firmware and the OS. + +The PCC driver (pcc-cpufreq) allows OSPM to take advantage of the PCC +interface. + +OS utilizes the PCC interface to inform platform firmware what frequency the +OS wants for a logical processor. The platform firmware attempts to achieve +the requested frequency. If the request for the target frequency could not be +satisfied by platform firmware, then it usually means that power budget +conditions are in place, and "power capping" is taking place. + +1.1 PCC interface: +------------------ +The complete PCC specification is available here: +http://www.acpica.org/download/Processor-Clocking-Control-v1p0.pdf + +PCC relies on a shared memory region that provides a channel for communication +between the OS and platform firmware. PCC also implements a "doorbell" that +is used by the OS to inform the platform firmware that a command has been +sent. + +The ACPI PCCH() method is used to discover the location of the PCC shared +memory region. The shared memory region header contains the "command" and +"status" interface. PCCH() also contains details on how to access the platform +doorbell. + +The following commands are supported by the PCC interface: +* Get Average Frequency +* Set Desired Frequency + +The ACPI PCCP() method is implemented for each logical processor and is +used to discover the offsets for the input and output buffers in the shared +memory region. + +When PCC mode is enabled, the platform will not expose processor performance +or throttle states (_PSS, _TSS and related ACPI objects) to OSPM. Therefore, +the native P-state driver (such as acpi-cpufreq for Intel, powernow-k8 for +AMD) will not load. + +However, OSPM remains in control of policy. The governor (eg: "ondemand") +computes the required performance for each processor based on server workload. +The PCC driver fills in the command interface, and the input buffer and +communicates the request to the platform firmware. The platform firmware is +responsible for delivering the requested performance. + +Each PCC command is "global" in scope and can affect all the logical CPUs in +the system. Therefore, PCC is capable of performing "group" updates. With PCC +the OS is capable of getting/setting the frequency of all the logical CPUs in +the system with a single call to the BIOS. + +1.1.1 Get Average Frequency: +---------------------------- +This command is used by the OSPM to query the running frequency of the +processor since the last time this command was completed. The output buffer +indicates the average unhalted frequency of the logical processor expressed as +a percentage of the nominal (ie: maximum) CPU frequency. The output buffer +also signifies if the CPU frequency is limited by a power budget condition. + +1.1.2 Set Desired Frequency: +---------------------------- +This command is used by the OSPM to communicate to the platform firmware the +desired frequency for a logical processor. The output buffer is currently +ignored by OSPM. The next invocation of "Get Average Frequency" will inform +OSPM if the desired frequency was achieved or not. + +1.2 Platforms affected: +----------------------- +The PCC driver will load on any system where the platform firmware: +* supports the PCC interface, and the associated PCCH() and PCCP() methods +* assumes responsibility for managing the hardware clocking controls in order +to deliver the requested processor performance + +Currently, certain HP ProLiant platforms implement the PCC interface. On those +platforms PCC is the "default" choice. + +However, it is possible to disable this interface via a BIOS setting. In +such an instance, as is also the case on platforms where the PCC interface +is not implemented, the PCC driver will fail to load silently. + +2. Driver and /sys details: +--------------------------- +When the driver loads, it merely prints the lowest and the highest CPU +frequencies supported by the platform firmware. + +The PCC driver loads with a message such as: +pcc-cpufreq: (v1.00.00) driver loaded with frequency limits: 1600 MHz, 2933 +MHz + +This means that the OPSM can request the CPU to run at any frequency in +between the limits (1600 MHz, and 2933 MHz) specified in the message. + +Internally, there is no need for the driver to convert the "target" frequency +to a corresponding P-state. + +The VERSION number for the driver will be of the format v.xy.ab. +eg: 1.00.02 + ----- -- + | | + | -- this will increase with bug fixes/enhancements to the driver + |-- this is the version of the PCC specification the driver adheres to + + +The following is a brief discussion on some of the fields exported via the +/sys filesystem and how their values are affected by the PCC driver: + +2.1 scaling_available_frequencies: +---------------------------------- +scaling_available_frequencies is not created in /sys. No intermediate +frequencies need to be listed because the BIOS will try to achieve any +frequency, within limits, requested by the governor. A frequency does not have +to be strictly associated with a P-state. + +2.2 cpuinfo_transition_latency: +------------------------------- +The cpuinfo_transition_latency field is 0. The PCC specification does +not include a field to expose this value currently. + +2.3 cpuinfo_cur_freq: +--------------------- +A) Often cpuinfo_cur_freq will show a value different than what is declared +in the scaling_available_frequencies or scaling_cur_freq, or scaling_max_freq. +This is due to "turbo boost" available on recent Intel processors. If certain +conditions are met the BIOS can achieve a slightly higher speed than requested +by OSPM. An example: + +scaling_cur_freq : 2933000 +cpuinfo_cur_freq : 3196000 + +B) There is a round-off error associated with the cpuinfo_cur_freq value. +Since the driver obtains the current frequency as a "percentage" (%) of the +nominal frequency from the BIOS, sometimes, the values displayed by +scaling_cur_freq and cpuinfo_cur_freq may not match. An example: + +scaling_cur_freq : 1600000 +cpuinfo_cur_freq : 1583000 + +In this example, the nominal frequency is 2933 MHz. The driver obtains the +current frequency, cpuinfo_cur_freq, as 54% of the nominal frequency: + + 54% of 2933 MHz = 1583 MHz + +Nominal frequency is the maximum frequency of the processor, and it usually +corresponds to the frequency of the P0 P-state. + +2.4 related_cpus: +----------------- +The related_cpus field is identical to affected_cpus. + +affected_cpus : 4 +related_cpus : 4 + +Currently, the PCC driver does not evaluate _PSD. The platforms that support +PCC do not implement SW_ALL. So OSPM doesn't need to perform any coordination +to ensure that the same frequency is requested of all dependent CPUs. + +3. Caveats: +----------- +The "cpufreq_stats" module in its present form cannot be loaded and +expected to work with the PCC driver. Since the "cpufreq_stats" module +provides information wrt each P-state, it is not applicable to the PCC driver. diff --git a/Documentation/device-mapper/snapshot.txt b/Documentation/device-mapper/snapshot.txt index e3a77b21513..0d5bc46dc16 100644 --- a/Documentation/device-mapper/snapshot.txt +++ b/Documentation/device-mapper/snapshot.txt @@ -122,3 +122,47 @@ volumeGroup-base: 0 2097152 snapshot-merge 254:11 254:12 P 16 brw------- 1 root root 254, 11 29 ago 18:15 /dev/mapper/volumeGroup-base-real brw------- 1 root root 254, 12 29 ago 18:16 /dev/mapper/volumeGroup-base-cow brw------- 1 root root 254, 10 29 ago 18:16 /dev/mapper/volumeGroup-base + + +How to determine when a merging is complete +=========================================== +The snapshot-merge and snapshot status lines end with: + <sectors_allocated>/<total_sectors> <metadata_sectors> + +Both <sectors_allocated> and <total_sectors> include both data and metadata. +During merging, the number of sectors allocated gets smaller and +smaller. Merging has finished when the number of sectors holding data +is zero, in other words <sectors_allocated> == <metadata_sectors>. + +Here is a practical example (using a hybrid of lvm and dmsetup commands): + +# lvs + LV VG Attr LSize Origin Snap% Move Log Copy% Convert + base volumeGroup owi-a- 4.00g + snap volumeGroup swi-a- 1.00g base 18.97 + +# dmsetup status volumeGroup-snap +0 8388608 snapshot 397896/2097152 1560 + ^^^^ metadata sectors + +# lvconvert --merge -b volumeGroup/snap + Merging of volume snap started. + +# lvs volumeGroup/snap + LV VG Attr LSize Origin Snap% Move Log Copy% Convert + base volumeGroup Owi-a- 4.00g 17.23 + +# dmsetup status volumeGroup-base +0 8388608 snapshot-merge 281688/2097152 1104 + +# dmsetup status volumeGroup-base +0 8388608 snapshot-merge 180480/2097152 712 + +# dmsetup status volumeGroup-base +0 8388608 snapshot-merge 16/2097152 16 + +Merging has finished. + +# lvs + LV VG Attr LSize Origin Snap% Move Log Copy% Convert + base volumeGroup owi-a- 4.00g diff --git a/Documentation/fault-injection/provoke-crashes.txt b/Documentation/fault-injection/provoke-crashes.txt new file mode 100644 index 00000000000..7a9d3d81525 --- /dev/null +++ b/Documentation/fault-injection/provoke-crashes.txt @@ -0,0 +1,38 @@ +The lkdtm module provides an interface to crash or injure the kernel at +predefined crashpoints to evaluate the reliability of crash dumps obtained +using different dumping solutions. The module uses KPROBEs to instrument +crashing points, but can also crash the kernel directly without KRPOBE +support. + + +You can provide the way either through module arguments when inserting +the module, or through a debugfs interface. + +Usage: insmod lkdtm.ko [recur_count={>0}] cpoint_name=<> cpoint_type=<> + [cpoint_count={>0}] + + recur_count : Recursion level for the stack overflow test. Default is 10. + + cpoint_name : Crash point where the kernel is to be crashed. It can be + one of INT_HARDWARE_ENTRY, INT_HW_IRQ_EN, INT_TASKLET_ENTRY, + FS_DEVRW, MEM_SWAPOUT, TIMERADD, SCSI_DISPATCH_CMD, + IDE_CORE_CP, DIRECT + + cpoint_type : Indicates the action to be taken on hitting the crash point. + It can be one of PANIC, BUG, EXCEPTION, LOOP, OVERFLOW, + CORRUPT_STACK, UNALIGNED_LOAD_STORE_WRITE, OVERWRITE_ALLOCATION, + WRITE_AFTER_FREE, + + cpoint_count : Indicates the number of times the crash point is to be hit + to trigger an action. The default is 10. + +You can also induce failures by mounting debugfs and writing the type to +<mountpoint>/provoke-crash/<crashpoint>. E.g., + + mount -t debugfs debugfs /mnt + echo EXCEPTION > /mnt/provoke-crash/INT_HARDWARE_ENTRY + + +A special file is `DIRECT' which will induce the crash directly without +KPROBE instrumentation. This mode is the only one available when the module +is built on a kernel without KPROBEs support. diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index 73ef30dbe61..a5cc0db63d7 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -117,19 +117,25 @@ Who: Mauro Carvalho Chehab <mchehab@infradead.org> --------------------------- What: PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl]) -When: November 2005 +When: 2.6.35/2.6.36 Files: drivers/pcmcia/: pcmcia_ioctl.c Why: With the 16-bit PCMCIA subsystem now behaving (almost) like a normal hotpluggable bus, and with it using the default kernel infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA control ioctl needed by cardmgr and cardctl from pcmcia-cs is - unnecessary, and makes further cleanups and integration of the + unnecessary and potentially harmful (it does not provide for + proper locking), and makes further cleanups and integration of the PCMCIA subsystem into the Linux kernel device driver model more difficult. The features provided by cardmgr and cardctl are either handled by the kernel itself now or are available in the new pcmciautils package available at http://kernel.org/pub/linux/utils/kernel/pcmcia/ -Who: Dominik Brodowski <linux@brodo.de> + + For all architectures except ARM, the associated config symbol + has been removed from kernel 2.6.34; for ARM, it will be likely + be removed from kernel 2.6.35. The actual code will then likely + be removed from kernel 2.6.36. +Who: Dominik Brodowski <linux@dominikbrodowski.net> --------------------------- @@ -443,12 +449,6 @@ Who: Alok N Kataria <akataria@vmware.com> ---------------------------- -What: adt7473 hardware monitoring driver -When: February 2010 -Why: Obsoleted by the adt7475 driver. -Who: Jean Delvare <khali@linux-fr.org> - ---------------------------- What: Support for lcd_switch and display_get in asus-laptop driver When: March 2010 Why: These two features use non-standard interfaces. There are the @@ -550,3 +550,35 @@ Why: udev fully replaces this special file system that only contains CAPI NCCI TTY device nodes. User space (pppdcapiplugin) works without noticing the difference. Who: Jan Kiszka <jan.kiszka@web.de> + +---------------------------- + +What: KVM memory aliases support +When: July 2010 +Why: Memory aliasing support is used for speeding up guest vga access + through the vga windows. + + Modern userspace no longer uses this feature, so it's just bitrotted + code and can be removed with no impact. +Who: Avi Kivity <avi@redhat.com> + +---------------------------- + +What: KVM kernel-allocated memory slots +When: July 2010 +Why: Since 2.6.25, kvm supports user-allocated memory slots, which are + much more flexible than kernel-allocated slots. All current userspace + supports the newer interface and this code can be removed with no + impact. +Who: Avi Kivity <avi@redhat.com> + +---------------------------- + +What: KVM paravirt mmu host support +When: January 2011 +Why: The paravirt mmu host support is slower than non-paravirt mmu, both + on newer and older hardware. It is already not exposed to the guest, + and kept only for live migration purposes. +Who: Avi Kivity <avi@redhat.com> + +---------------------------- diff --git a/Documentation/filesystems/00-INDEX b/Documentation/filesystems/00-INDEX index 875d49696b6..5139b8c9d5a 100644 --- a/Documentation/filesystems/00-INDEX +++ b/Documentation/filesystems/00-INDEX @@ -62,6 +62,8 @@ jfs.txt - info and mount options for the JFS filesystem. locks.txt - info on file locking implementations, flock() vs. fcntl(), etc. +logfs.txt + - info on the LogFS flash filesystem. mandatory-locking.txt - info on the Linux implementation of Sys V mandatory file locking. ncpfs.txt diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index 18b9d0ca063..06bbbed7120 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -460,13 +460,6 @@ in sys_read() and friends. --------------------------- dquot_operations ------------------------------- prototypes: - int (*initialize) (struct inode *, int); - int (*drop) (struct inode *); - int (*alloc_space) (struct inode *, qsize_t, int); - int (*alloc_inode) (const struct inode *, unsigned long); - int (*free_space) (struct inode *, qsize_t); - int (*free_inode) (const struct inode *, unsigned long); - int (*transfer) (struct inode *, struct iattr *); int (*write_dquot) (struct dquot *); int (*acquire_dquot) (struct dquot *); int (*release_dquot) (struct dquot *); @@ -479,13 +472,6 @@ a proper locking wrt the filesystem and call the generic quota operations. What filesystem should expect from the generic quota functions: FS recursion Held locks when called -initialize: yes maybe dqonoff_sem -drop: yes - -alloc_space: ->mark_dirty() - -alloc_inode: ->mark_dirty() - -free_space: ->mark_dirty() - -free_inode: ->mark_dirty() - -transfer: yes - write_dquot: yes dqonoff_sem or dqptr_sem acquire_dquot: yes dqonoff_sem or dqptr_sem release_dquot: yes dqonoff_sem or dqptr_sem @@ -495,10 +481,6 @@ write_info: yes dqonoff_sem FS recursion means calling ->quota_read() and ->quota_write() from superblock operations. -->alloc_space(), ->alloc_inode(), ->free_space(), ->free_inode() are called -only directly by the filesystem and do not call any fs functions only -the ->mark_dirty() operation. - More details about quota locking can be found in fs/dquot.c. --------------------------- vm_operations_struct ----------------------------- diff --git a/Documentation/filesystems/logfs.txt b/Documentation/filesystems/logfs.txt new file mode 100644 index 00000000000..e64c94ba401 --- /dev/null +++ b/Documentation/filesystems/logfs.txt @@ -0,0 +1,241 @@ + +The LogFS Flash Filesystem +========================== + +Specification +============= + +Superblocks +----------- + +Two superblocks exist at the beginning and end of the filesystem. +Each superblock is 256 Bytes large, with another 3840 Bytes reserved +for future purposes, making a total of 4096 Bytes. + +Superblock locations may differ for MTD and block devices. On MTD the +first non-bad block contains a superblock in the first 4096 Bytes and +the last non-bad block contains a superblock in the last 4096 Bytes. +On block devices, the first 4096 Bytes of the device contain the first +superblock and the last aligned 4096 Byte-block contains the second +superblock. + +For the most part, the superblocks can be considered read-only. They +are written only to correct errors detected within the superblocks, +move the journal and change the filesystem parameters through tunefs. +As a result, the superblock does not contain any fields that require +constant updates, like the amount of free space, etc. + +Segments +-------- + +The space in the device is split up into equal-sized segments. +Segments are the primary write unit of LogFS. Within each segments, +writes happen from front (low addresses) to back (high addresses. If +only a partial segment has been written, the segment number, the +current position within and optionally a write buffer are stored in +the journal. + +Segments are erased as a whole. Therefore Garbage Collection may be +required to completely free a segment before doing so. + +Journal +-------- + +The journal contains all global information about the filesystem that +is subject to frequent change. At mount time, it has to be scanned +for the most recent commit entry, which contains a list of pointers to +all currently valid entries. + +Object Store +------------ + +All space except for the superblocks and journal is part of the object +store. Each segment contains a segment header and a number of +objects, each consisting of the object header and the payload. +Objects are either inodes, directory entries (dentries), file data +blocks or indirect blocks. + +Levels +------ + +Garbage collection (GC) may fail if all data is written +indiscriminately. One requirement of GC is that data is seperated +roughly according to the distance between the tree root and the data. +Effectively that means all file data is on level 0, indirect blocks +are on levels 1, 2, 3 4 or 5 for 1x, 2x, 3x, 4x or 5x indirect blocks, +respectively. Inode file data is on level 6 for the inodes and 7-11 +for indirect blocks. + +Each segment contains objects of a single level only. As a result, +each level requires its own seperate segment to be open for writing. + +Inode File +---------- + +All inodes are stored in a special file, the inode file. Single +exception is the inode file's inode (master inode) which for obvious +reasons is stored in the journal instead. Instead of data blocks, the +leaf nodes of the inode files are inodes. + +Aliases +------- + +Writes in LogFS are done by means of a wandering tree. A naïve +implementation would require that for each write or a block, all +parent blocks are written as well, since the block pointers have +changed. Such an implementation would not be very efficient. + +In LogFS, the block pointer changes are cached in the journal by means +of alias entries. Each alias consists of its logical address - inode +number, block index, level and child number (index into block) - and +the changed data. Any 8-byte word can be changes in this manner. + +Currently aliases are used for block pointers, file size, file used +bytes and the height of an inodes indirect tree. + +Segment Aliases +--------------- + +Related to regular aliases, these are used to handle bad blocks. +Initially, bad blocks are handled by moving the affected segment +content to a spare segment and noting this move in the journal with a +segment alias, a simple (to, from) tupel. GC will later empty this +segment and the alias can be removed again. This is used on MTD only. + +Vim +--- + +By cleverly predicting the life time of data, it is possible to +seperate long-living data from short-living data and thereby reduce +the GC overhead later. Each type of distinc life expectency (vim) can +have a seperate segment open for writing. Each (level, vim) tupel can +be open just once. If an open segment with unknown vim is encountered +at mount time, it is closed and ignored henceforth. + +Indirect Tree +------------- + +Inodes in LogFS are similar to FFS-style filesystems with direct and +indirect block pointers. One difference is that LogFS uses a single +indirect pointer that can be either a 1x, 2x, etc. indirect pointer. +A height field in the inode defines the height of the indirect tree +and thereby the indirection of the pointer. + +Another difference is the addressing of indirect blocks. In LogFS, +the first 16 pointers in the first indirect block are left empty, +corresponding to the 16 direct pointers in the inode. In ext2 (maybe +others as well) the first pointer in the first indirect block +corresponds to logical block 12, skipping the 12 direct pointers. +So where ext2 is using arithmetic to better utilize space, LogFS keeps +arithmetic simple and uses compression to save space. + +Compression +----------- + +Both file data and metadata can be compressed. Compression for file +data can be enabled with chattr +c and disabled with chattr -c. Doing +so has no effect on existing data, but new data will be stored +accordingly. New inodes will inherit the compression flag of the +parent directory. + +Metadata is always compressed. However, the space accounting ignores +this and charges for the uncompressed size. Failing to do so could +result in GC failures when, after moving some data, indirect blocks +compress worse than previously. Even on a 100% full medium, GC may +not consume any extra space, so the compression gains are lost space +to the user. + +However, they are not lost space to the filesystem internals. By +cheating the user for those bytes, the filesystem gained some slack +space and GC will run less often and faster. + +Garbage Collection and Wear Leveling +------------------------------------ + +Garbage collection is invoked whenever the number of free segments +falls below a threshold. The best (known) candidate is picked based +on the least amount of valid data contained in the segment. All +remaining valid data is copied elsewhere, thereby invalidating it. + +The GC code also checks for aliases and writes then back if their +number gets too large. + +Wear leveling is done by occasionally picking a suboptimal segment for +garbage collection. If a stale segments erase count is significantly +lower than the active segments' erase counts, it will be picked. Wear +leveling is rate limited, so it will never monopolize the device for +more than one segment worth at a time. + +Values for "occasionally", "significantly lower" are compile time +constants. + +Hashed directories +------------------ + +To satisfy efficient lookup(), directory entries are hashed and +located based on the hash. In order to both support large directories +and not be overly inefficient for small directories, several hash +tables of increasing size are used. For each table, the hash value +modulo the table size gives the table index. + +Tables sizes are chosen to limit the number of indirect blocks with a +fully populated table to 0, 1, 2 or 3 respectively. So the first +table contains 16 entries, the second 512-16, etc. + +The last table is special in several ways. First its size depends on +the effective 32bit limit on telldir/seekdir cookies. Since logfs +uses the upper half of the address space for indirect blocks, the size +is limited to 2^31. Secondly the table contains hash buckets with 16 +entries each. + +Using single-entry buckets would result in birthday "attacks". At +just 2^16 used entries, hash collisions would be likely (P >= 0.5). +My math skills are insufficient to do the combinatorics for the 17x +collisions necessary to overflow a bucket, but testing showed that in +10,000 runs the lowest directory fill before a bucket overflow was +188,057,130 entries with an average of 315,149,915 entries. So for +directory sizes of up to a million, bucket overflows should be +virtually impossible under normal circumstances. + +With carefully chosen filenames, it is obviously possible to cause an +overflow with just 21 entries (4 higher tables + 16 entries + 1). So +there may be a security concern if a malicious user has write access +to a directory. + +Open For Discussion +=================== + +Device Address Space +-------------------- + +A device address space is used for caching. Both block devices and +MTD provide functions to either read a single page or write a segment. +Partial segments may be written for data integrity, but where possible +complete segments are written for performance on simple block device +flash media. + +Meta Inodes +----------- + +Inodes are stored in the inode file, which is just a regular file for +most purposes. At umount time, however, the inode file needs to +remain open until all dirty inodes are written. So +generic_shutdown_super() may not close this inode, but shouldn't +complain about remaining inodes due to the inode file either. Same +goes for mapping inode of the device address space. + +Currently logfs uses a hack that essentially copies part of fs/inode.c +code over. A general solution would be preferred. + +Indirect block mapping +---------------------- + +With compression, the block device (or mapping inode) cannot be used +to cache indirect blocks. Some other place is required. Currently +logfs uses the top half of each inode's address space. The low 8TB +(on 32bit) are filled with file data, the high 8TB are used for +indirect blocks. + +One problem is that 16TB files created on 64bit systems actually have +data in the top 8TB. But files >16TB would cause problems anyway, so +only the limit has changed. diff --git a/Documentation/filesystems/nfs/nfs41-server.txt b/Documentation/filesystems/nfs/nfs41-server.txt index 1bd0d0c0517..6a53a84afc7 100644 --- a/Documentation/filesystems/nfs/nfs41-server.txt +++ b/Documentation/filesystems/nfs/nfs41-server.txt @@ -17,8 +17,7 @@ kernels must turn 4.1 on or off *before* turning support for version 4 on or off; rpc.nfsd does this correctly.) The NFSv4 minorversion 1 (NFSv4.1) implementation in nfsd is based -on the latest NFSv4.1 Internet Draft: -http://tools.ietf.org/html/draft-ietf-nfsv4-minorversion1-29 +on RFC 5661. From the many new features in NFSv4.1 the current implementation focuses on the mandatory-to-implement NFSv4.1 Sessions, providing @@ -44,7 +43,7 @@ interoperability problems with future clients. Known issues: trunking, but this is a mandatory feature, and its use is recommended to clients in a number of places. (E.g. to ensure timely renewal in case an existing connection's retry timeouts - have gotten too long; see section 8.3 of the draft.) + have gotten too long; see section 8.3 of the RFC.) Therefore, lack of this feature may cause future clients to fail. - Incomplete backchannel support: incomplete backchannel gss diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index 0d07513a67a..96a44dd95e0 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -164,6 +164,7 @@ read the file /proc/PID/status: VmExe: 68 kB VmLib: 1412 kB VmPTE: 20 kb + VmSwap: 0 kB Threads: 1 SigQ: 0/28578 SigPnd: 0000000000000000 @@ -188,6 +189,12 @@ memory usage. Its seven fields are explained in Table 1-3. The stat file contains details information about the process itself. Its fields are explained in Table 1-4. +(for SMP CONFIG users) +For making accounting scalable, RSS related information are handled in +asynchronous manner and the vaule may not be very precise. To see a precise +snapshot of a moment, you can see /proc/<pid>/smaps file and scan page table. +It's slow but very precise. + Table 1-2: Contents of the statm files (as of 2.6.30-rc7) .............................................................................. Field Content @@ -213,6 +220,7 @@ Table 1-2: Contents of the statm files (as of 2.6.30-rc7) VmExe size of text segment VmLib size of shared library code VmPTE size of page table entries + VmSwap size of swap usage (the number of referred swapents) Threads number of threads SigQ number of signals queued/max. number for queue SigPnd bitmap of pending signals for the thread @@ -430,6 +438,7 @@ Table 1-5: Kernel info in /proc modules List of loaded modules mounts Mounted filesystems net Networking info (see text) + pagetypeinfo Additional page allocator information (see text) (2.5) partitions Table of partitions known to the system pci Deprecated info of PCI bus (new way -> /proc/bus/pci/, decoupled by lspci (2.4) @@ -584,7 +593,7 @@ Node 0, zone DMA 0 4 5 4 4 3 ... Node 0, zone Normal 1 0 0 1 101 8 ... Node 0, zone HighMem 2 0 0 1 1 0 ... -Memory fragmentation is a problem under some workloads, and buddyinfo is a +External fragmentation is a problem under some workloads, and buddyinfo is a useful tool for helping diagnose these problems. Buddyinfo will give you a clue as to how big an area you can safely allocate, or why a previous allocation failed. @@ -594,6 +603,48 @@ available. In this case, there are 0 chunks of 2^0*PAGE_SIZE available in ZONE_DMA, 4 chunks of 2^1*PAGE_SIZE in ZONE_DMA, 101 chunks of 2^4*PAGE_SIZE available in ZONE_NORMAL, etc... +More information relevant to external fragmentation can be found in +pagetypeinfo. + +> cat /proc/pagetypeinfo +Page block order: 9 +Pages per block: 512 + +Free pages count per migrate type at order 0 1 2 3 4 5 6 7 8 9 10 +Node 0, zone DMA, type Unmovable 0 0 0 1 1 1 1 1 1 1 0 +Node 0, zone DMA, type Reclaimable 0 0 0 0 0 0 0 0 0 0 0 +Node 0, zone DMA, type Movable 1 1 2 1 2 1 1 0 1 0 2 +Node 0, zone DMA, type Reserve 0 0 0 0 0 0 0 0 0 1 0 +Node 0, zone DMA, type Isolate 0 0 0 0 0 0 0 0 0 0 0 +Node 0, zone DMA32, type Unmovable 103 54 77 1 1 1 11 8 7 1 9 +Node 0, zone DMA32, type Reclaimable 0 0 2 1 0 0 0 0 1 0 0 +Node 0, zone DMA32, type Movable 169 152 113 91 77 54 39 13 6 1 452 +Node 0, zone DMA32, type Reserve 1 2 2 2 2 0 1 1 1 1 0 +Node 0, zone DMA32, type Isolate 0 0 0 0 0 0 0 0 0 0 0 + +Number of blocks type Unmovable Reclaimable Movable Reserve Isolate +Node 0, zone DMA 2 0 5 1 0 +Node 0, zone DMA32 41 6 967 2 0 + +Fragmentation avoidance in the kernel works by grouping pages of different +migrate types into the same contiguous regions of memory called page blocks. +A page block is typically the size of the default hugepage size e.g. 2MB on +X86-64. By keeping pages grouped based on their ability to move, the kernel +can reclaim pages within a page block to satisfy a high-order allocation. + +The pagetypinfo begins with information on the size of a page block. It +then gives the same type of information as buddyinfo except broken down +by migrate-type and finishes with details on how many page blocks of each +type exist. + +If min_free_kbytes has been tuned correctly (recommendations made by hugeadm +from libhugetlbfs http://sourceforge.net/projects/libhugetlbfs/), one can +make an estimate of the likely number of huge pages that can be allocated +at a given point in time. All the "Movable" blocks should be allocatable +unless memory has been mlock()'d. Some of the Reclaimable blocks should +also be allocatable although a lot of filesystem metadata may have to be +reclaimed to achieve this. + .............................................................................. meminfo: diff --git a/Documentation/filesystems/sharedsubtree.txt b/Documentation/filesystems/sharedsubtree.txt index 23a181074f9..fc0e39af43c 100644 --- a/Documentation/filesystems/sharedsubtree.txt +++ b/Documentation/filesystems/sharedsubtree.txt @@ -837,6 +837,9 @@ replicas continue to be exactly same. individual lists does not affect propagation or the way propagation tree is modified by operations. + All vfsmounts in a peer group have the same ->mnt_master. If it is + non-NULL, they form a contiguous (ordered) segment of slave list. + A example propagation tree looks as shown in the figure below. [ NOTE: Though it looks like a forest, if we consider all the shared mounts as a conceptual entity called 'pnode', it becomes a tree] @@ -874,8 +877,19 @@ replicas continue to be exactly same. NOTE: The propagation tree is orthogonal to the mount tree. +8B Locking: + + ->mnt_share, ->mnt_slave, ->mnt_slave_list, ->mnt_master are protected + by namespace_sem (exclusive for modifications, shared for reading). + + Normally we have ->mnt_flags modifications serialized by vfsmount_lock. + There are two exceptions: do_add_mount() and clone_mnt(). + The former modifies a vfsmount that has not been visible in any shared + data structures yet. + The latter holds namespace_sem and the only references to vfsmount + are in lists that can't be traversed without namespace_sem. -8B Algorithm: +8C Algorithm: The crux of the implementation resides in rbind/move operation. diff --git a/Documentation/gpio.txt b/Documentation/gpio.txt index 1866c27eec6..c2c6e9b39bb 100644 --- a/Documentation/gpio.txt +++ b/Documentation/gpio.txt @@ -253,6 +253,70 @@ pin setup (e.g. controlling which pin the GPIO uses, pullup/pulldown). Also note that it's your responsibility to have stopped using a GPIO before you free it. +Considering in most cases GPIOs are actually configured right after they +are claimed, three additional calls are defined: + + /* request a single GPIO, with initial configuration specified by + * 'flags', identical to gpio_request() wrt other arguments and + * return value + */ + int gpio_request_one(unsigned gpio, unsigned long flags, const char *label); + + /* request multiple GPIOs in a single call + */ + int gpio_request_array(struct gpio *array, size_t num); + + /* release multiple GPIOs in a single call + */ + void gpio_free_array(struct gpio *array, size_t num); + +where 'flags' is currently defined to specify the following properties: + + * GPIOF_DIR_IN - to configure direction as input + * GPIOF_DIR_OUT - to configure direction as output + + * GPIOF_INIT_LOW - as output, set initial level to LOW + * GPIOF_INIT_HIGH - as output, set initial level to HIGH + +since GPIOF_INIT_* are only valid when configured as output, so group valid +combinations as: + + * GPIOF_IN - configure as input + * GPIOF_OUT_INIT_LOW - configured as output, initial level LOW + * GPIOF_OUT_INIT_HIGH - configured as output, initial level HIGH + +In the future, these flags can be extended to support more properties such +as open-drain status. + +Further more, to ease the claim/release of multiple GPIOs, 'struct gpio' is +introduced to encapsulate all three fields as: + + struct gpio { + unsigned gpio; + unsigned long flags; + const char *label; + }; + +A typical example of usage: + + static struct gpio leds_gpios[] = { + { 32, GPIOF_OUT_INIT_HIGH, "Power LED" }, /* default to ON */ + { 33, GPIOF_OUT_INIT_LOW, "Green LED" }, /* default to OFF */ + { 34, GPIOF_OUT_INIT_LOW, "Red LED" }, /* default to OFF */ + { 35, GPIOF_OUT_INIT_LOW, "Blue LED" }, /* default to OFF */ + { ... }, + }; + + err = gpio_request_one(31, GPIOF_IN, "Reset Button"); + if (err) + ... + + err = gpio_request_array(leds_gpios, ARRAY_SIZE(leds_gpios)); + if (err) + ... + + gpio_free_array(leds_gpios, ARRAY_SIZE(leds_gpios)); + GPIOs mapped to IRQs -------------------- diff --git a/Documentation/hwmon/adt7411 b/Documentation/hwmon/adt7411 new file mode 100644 index 00000000000..1632960f974 --- /dev/null +++ b/Documentation/hwmon/adt7411 @@ -0,0 +1,42 @@ +Kernel driver adt7411 +===================== + +Supported chips: + * Analog Devices ADT7411 + Prefix: 'adt7411' + Addresses scanned: 0x48, 0x4a, 0x4b + Datasheet: Publicly available at the Analog Devices website + +Author: Wolfram Sang (based on adt7470 by Darrick J. Wong) + +Description +----------- + +This driver implements support for the Analog Devices ADT7411 chip. There may +be other chips that implement this interface. + +The ADT7411 can use an I2C/SMBus compatible 2-wire interface or an +SPI-compatible 4-wire interface. It provides a 10-bit analog to digital +converter which measures 1 temperature, vdd and 8 input voltages. It has an +internal temperature sensor, but an external one can also be connected (one +loses 2 inputs then). There are high- and low-limit registers for all inputs. + +Check the datasheet for details. + +sysfs-Interface +--------------- + +in0_input - vdd voltage input +in[1-8]_input - analog 1-8 input +temp1_input - temperature input + +Besides standard interfaces, this driver adds (0 = off, 1 = on): + + adc_ref_vdd - Use vdd as reference instead of 2.25 V + fast_sampling - Sample at 22.5 kHz instead of 1.4 kHz, but drop filters + no_average - Turn off averaging over 16 samples + +Notes +----- + +SPI, external temperature sensor and limit registers are not supported yet. diff --git a/Documentation/hwmon/adt7473 b/Documentation/hwmon/adt7473 deleted file mode 100644 index 446612bd1fb..00000000000 --- a/Documentation/hwmon/adt7473 +++ /dev/null @@ -1,74 +0,0 @@ -Kernel driver adt7473 -====================== - -Supported chips: - * Analog Devices ADT7473 - Prefix: 'adt7473' - Addresses scanned: I2C 0x2C, 0x2D, 0x2E - Datasheet: Publicly available at the Analog Devices website - -Author: Darrick J. Wong - -This driver is depreacted, please use the adt7475 driver instead. - -Description ------------ - -This driver implements support for the Analog Devices ADT7473 chip family. - -The ADT7473 uses the 2-wire interface compatible with the SMBUS 2.0 -specification. Using an analog to digital converter it measures three (3) -temperatures and two (2) voltages. It has four (4) 16-bit counters for -measuring fan speed. There are three (3) PWM outputs that can be used -to control fan speed. - -A sophisticated control system for the PWM outputs is designed into the -ADT7473 that allows fan speed to be adjusted automatically based on any of the -three temperature sensors. Each PWM output is individually adjustable and -programmable. Once configured, the ADT7473 will adjust the PWM outputs in -response to the measured temperatures without further host intervention. -This feature can also be disabled for manual control of the PWM's. - -Each of the measured inputs (voltage, temperature, fan speed) has -corresponding high/low limit values. The ADT7473 will signal an ALARM if -any measured value exceeds either limit. - -The ADT7473 samples all inputs continuously. The driver will not read -the registers more often than once every other second. Further, -configuration data is only read once per minute. - -Special Features ----------------- - -The ADT7473 have a 10-bit ADC and can therefore measure temperatures -with 0.25 degC resolution. Temperature readings can be configured either -for twos complement format or "Offset 64" format, wherein 63 is subtracted -from the raw value to get the temperature value. - -The Analog Devices datasheet is very detailed and describes a procedure for -determining an optimal configuration for the automatic PWM control. - -Configuration Notes -------------------- - -Besides standard interfaces driver adds the following: - -* PWM Control - -* pwm#_auto_point1_pwm and temp#_auto_point1_temp and -* pwm#_auto_point2_pwm and temp#_auto_point2_temp - - -point1: Set the pwm speed at a lower temperature bound. -point2: Set the pwm speed at a higher temperature bound. - -The ADT7473 will scale the pwm between the lower and higher pwm speed when -the temperature is between the two temperature boundaries. PWM values range -from 0 (off) to 255 (full speed). Fan speed will be set to maximum when the -temperature sensor associated with the PWM control exceeds temp#_max. - -Notes ------ - -The NVIDIA binary driver presents an ADT7473 chip via an on-card i2c bus. -Unfortunately, they fail to set the i2c adapter class, so this driver may -fail to find the chip until the nvidia driver is patched. diff --git a/Documentation/hwmon/asc7621 b/Documentation/hwmon/asc7621 new file mode 100644 index 00000000000..7287be7e1f2 --- /dev/null +++ b/Documentation/hwmon/asc7621 @@ -0,0 +1,296 @@ +Kernel driver asc7621 +================== + +Supported chips: + Andigilog aSC7621 and aSC7621a + Prefix: 'asc7621' + Addresses scanned: I2C 0x2c, 0x2d, 0x2e + Datasheet: http://www.fairview5.com/linux/asc7621/asc7621.pdf + +Author: + George Joseph + +Description provided by Dave Pivin @ Andigilog: + +Andigilog has both the PECI and pre-PECI versions of the Heceta-6, as +Intel calls them. Heceta-6e has high frequency PWM and Heceta-6p has +added PECI and a 4th thermal zone. The Andigilog aSC7611 is the +Heceta-6e part and aSC7621 is the Heceta-6p part. They are both in +volume production, shipping to Intel and their subs. + +We have enhanced both parts relative to the governing Intel +specification. First enhancement is temperature reading resolution. We +have used registers below 20h for vendor-specific functions in addition +to those in the Intel-specified vendor range. + +Our conversion process produces a result that is reported as two bytes. +The fan speed control uses this finer value to produce a "step-less" fan +PWM output. These two bytes are "read-locked" to guarantee that once a +high or low byte is read, the other byte is locked-in until after the +next read of any register. So to get an atomic reading, read high or low +byte, then the very next read should be the opposite byte. Our data +sheet says 10-bits of resolution, although you may find the lower bits +are active, they are not necessarily reliable or useful externally. We +chose not to mask them. + +We employ significant filtering that is user tunable as described in the +data sheet. Our temperature reports and fan PWM outputs are very smooth +when compared to the competition, in addition to the higher resolution +temperature reports. The smoother PWM output does not require user +intervention. + +We offer GPIO features on the former VID pins. These are open-drain +outputs or inputs and may be used as general purpose I/O or as alarm +outputs that are based on temperature limits. These are in 19h and 1Ah. + +We offer flexible mapping of temperature readings to thermal zones. Any +temperature may be mapped to any zone, which has a default assignment +that follows Intel's specs. + +Since there is a fan to zone assignment that allows for the "hotter" of +a set of zones to control the PWM of an individual fan, but there is no +indication to the user, we have added an indicator that shows which zone +is currently controlling the PWM for a given fan. This is in register +00h. + +Both remote diode temperature readings may be given an offset value such +that the reported reading as well as the temperature used to determine +PWM may be offset for system calibration purposes. + +PECI Extended configuration allows for having more than two domains per +PECI address and also provides an enabling function for each PECI +address. One could use our flexible zone assignment to have a zone +assigned to up to 4 PECI addresses. This is not possible in the default +Intel configuration. This would be useful in multi-CPU systems with +individual fans on each that would benefit from individual fan control. +This is in register 0Eh. + +The tachometer measurement system is flexible and able to adapt to many +fan types. We can also support pulse-stretched PWM so that 3-wire fans +may be used. These characteristics are in registers 04h to 07h. + +Finally, we have added a tach disable function that turns off the tach +measurement system for individual tachs in order to save power. That is +in register 75h. + +-- +aSC7621 Product Description + +The aSC7621 has a two wire digital interface compatible with SMBus 2.0. +Using a 10-bit ADC, the aSC7621 measures the temperature of two remote diode +connected transistors as well as its own die. Support for Platform +Environmental Control Interface (PECI) is included. + +Using temperature information from these four zones, an automatic fan speed +control algorithm is employed to minimize acoustic impact while achieving +recommended CPU temperature under varying operational loads. + +To set fan speed, the aSC7621 has three independent pulse width modulation +(PWM) outputs that are controlled by one, or a combination of three, +temperature zones. Both high- and low-frequency PWM ranges are supported. + +The aSC7621 also includes a digital filter that can be invoked to smooth +temperature readings for better control of fan speed and minimum acoustic +impact. + +The aSC7621 has tachometer inputs to measure fan speed on up to four fans. +Limit and status registers for all measured values are included to alert +the system host that any measurements are outside of programmed limits +via status registers. + +System voltages of VCCP, 2.5V, 3.3V, 5.0V, and 12V motherboard power are +monitored efficiently with internal scaling resistors. + +Features +- Supports PECI interface and monitors internal and remote thermal diodes +- 2-wire, SMBus 2.0 compliant, serial interface +- 10-bit ADC +- Monitors VCCP, 2.5V, 3.3V, 5.0V, and 12V motherboard/processor supplies +- Programmable autonomous fan control based on temperature readings +- Noise filtering of temperature reading for fan speed control +- 0.25C digital temperature sensor resolution +- 3 PWM fan speed control outputs for 2-, 3- or 4-wire fans and up to 4 fan + tachometer inputs +- Enhanced measured temperature to Temperature Zone assignment. +- Provides high and low PWM frequency ranges +- 3 GPIO pins for custom use +- 24-Lead QSOP package + +Configuration Notes +=================== + +Except where noted below, the sysfs entries created by this driver follow +the standards defined in "sysfs-interface". + +temp1_source + 0 (default) peci_legacy = 0, Remote 1 Temperature + peci_legacy = 1, PECI Processor Temperature 0 + 1 Remote 1 Temperature + 2 Remote 2 Temperature + 3 Internal Temperature + 4 PECI Processor Temperature 0 + 5 PECI Processor Temperature 1 + 6 PECI Processor Temperature 2 + 7 PECI Processor Temperature 3 + +temp2_source + 0 (default) Internal Temperature + 1 Remote 1 Temperature + 2 Remote 2 Temperature + 3 Internal Temperature + 4 PECI Processor Temperature 0 + 5 PECI Processor Temperature 1 + 6 PECI Processor Temperature 2 + 7 PECI Processor Temperature 3 + +temp3_source + 0 (default) Remote 2 Temperature + 1 Remote 1 Temperature + 2 Remote 2 Temperature + 3 Internal Temperature + 4 PECI Processor Temperature 0 + 5 PECI Processor Temperature 1 + 6 PECI Processor Temperature 2 + 7 PECI Processor Temperature 3 + +temp4_source + 0 (default) peci_legacy = 0, PECI Processor Temperature 0 + peci_legacy = 1, Remote 1 Temperature + 1 Remote 1 Temperature + 2 Remote 2 Temperature + 3 Internal Temperature + 4 PECI Processor Temperature 0 + 5 PECI Processor Temperature 1 + 6 PECI Processor Temperature 2 + 7 PECI Processor Temperature 3 + +temp[1-4]_smoothing_enable +temp[1-4]_smoothing_time + Smooths spikes in temp readings caused by noise. + Valid values in milliseconds are: + 35000 + 17600 + 11800 + 7000 + 4400 + 3000 + 1600 + 800 + +temp[1-4]_crit + When the corresponding zone temperature reaches this value, + ALL pwm outputs will got to 100%. + +temp[5-8]_input +temp[5-8]_enable + The aSC7621 can also read temperatures provided by the processor + via the PECI bus. Usually these are "core" temps and are relative + to the point where the automatic thermal control circuit starts + throttling. This means that these are usually negative numbers. + +pwm[1-3]_enable + 0 Fan off. + 1 Fan on manual control. + 2 Fan on automatic control and will run at the minimum pwm + if the temperature for the zone is below the minimum. + 3 Fan on automatic control but will be off if the temperature + for the zone is below the minimum. + 4-254 Ignored. + 255 Fan on full. + +pwm[1-3]_auto_channels + Bitmap as described in sysctl-interface with the following + exceptions... + Only the following combination of zones (and their corresponding masks) + are valid: + 1 + 2 + 3 + 2,3 + 1,2,3 + 4 + 1,2,3,4 + + Special values: + 0 Disabled. + 16 Fan on manual control. + 31 Fan on full. + + +pwm[1-3]_invert + When set, inverts the meaning of pwm[1-3]. + i.e. when pwm = 0, the fan will be on full and + when pwm = 255 the fan will be off. + +pwm[1-3]_freq + PWM frequency in Hz + Valid values in Hz are: + + 10 + 15 + 23 + 30 (default) + 38 + 47 + 62 + 94 + 23000 + 24000 + 25000 + 26000 + 27000 + 28000 + 29000 + 30000 + + Setting any other value will be ignored. + +peci_enable + Enables or disables PECI + +peci_avg + Input filter average time. + + 0 0 Sec. (no Smoothing) (default) + 1 0.25 Sec. + 2 0.5 Sec. + 3 1.0 Sec. + 4 2.0 Sec. + 5 4.0 Sec. + 6 8.0 Sec. + 7 0.0 Sec. + +peci_legacy + + 0 Standard Mode (default) + Remote Diode 1 reading is associated with + Temperature Zone 1, PECI is associated with + Zone 4 + + 1 Legacy Mode + PECI is associated with Temperature Zone 1, + Remote Diode 1 is associated with Zone 4 + +peci_diode + Diode filter + + 0 0.25 Sec. + 1 1.1 Sec. + 2 2.4 Sec. (default) + 3 3.4 Sec. + 4 5.0 Sec. + 5 6.8 Sec. + 6 10.2 Sec. + 7 16.4 Sec. + +peci_4domain + Four domain enable + + 0 1 or 2 Domains for enabled processors (default) + 1 3 or 4 Domains for enabled processors + +peci_domain + Domain + + 0 Processor contains a single domain (0) (default) + 1 Processor contains two domains (0,1) diff --git a/Documentation/hwmon/it87 b/Documentation/hwmon/it87 index f9ba96c0ac4..8d08bf0d38e 100644 --- a/Documentation/hwmon/it87 +++ b/Documentation/hwmon/it87 @@ -5,31 +5,23 @@ Supported chips: * IT8705F Prefix: 'it87' Addresses scanned: from Super I/O config space (8 I/O ports) - Datasheet: Publicly available at the ITE website - http://www.ite.com.tw/product_info/file/pc/IT8705F_V.0.4.1.pdf + Datasheet: Once publicly available at the ITE website, but no longer * IT8712F Prefix: 'it8712' Addresses scanned: from Super I/O config space (8 I/O ports) - Datasheet: Publicly available at the ITE website - http://www.ite.com.tw/product_info/file/pc/IT8712F_V0.9.1.pdf - http://www.ite.com.tw/product_info/file/pc/Errata%20V0.1%20for%20IT8712F%20V0.9.1.pdf - http://www.ite.com.tw/product_info/file/pc/IT8712F_V0.9.3.pdf + Datasheet: Once publicly available at the ITE website, but no longer * IT8716F/IT8726F Prefix: 'it8716' Addresses scanned: from Super I/O config space (8 I/O ports) - Datasheet: Publicly available at the ITE website - http://www.ite.com.tw/product_info/file/pc/IT8716F_V0.3.ZIP - http://www.ite.com.tw/product_info/file/pc/IT8726F_V0.3.pdf + Datasheet: Once publicly available at the ITE website, but no longer * IT8718F Prefix: 'it8718' Addresses scanned: from Super I/O config space (8 I/O ports) - Datasheet: Publicly available at the ITE website - http://www.ite.com.tw/product_info/file/pc/IT8718F_V0.2.zip - http://www.ite.com.tw/product_info/file/pc/IT8718F_V0%203_(for%20C%20version).zip + Datasheet: Once publicly available at the ITE website, but no longer * IT8720F Prefix: 'it8720' Addresses scanned: from Super I/O config space (8 I/O ports) - Datasheet: Not yet publicly available. + Datasheet: Not publicly available * SiS950 [clone of IT8705F] Prefix: 'it87' Addresses scanned: from Super I/O config space (8 I/O ports) @@ -136,6 +128,10 @@ registers are read whenever any data is read (unless it is less than 1.5 seconds since the last update). This means that you can easily miss once-only alarms. +Out-of-limit readings can also result in beeping, if the chip is properly +wired and configured. Beeping can be enabled or disabled per sensor type +(temperatures, voltages and fans.) + The IT87xx only updates its values each 1.5 seconds; reading it more often will do no harm, but will return 'old' values. @@ -150,11 +146,38 @@ Fan speed control ----------------- The fan speed control features are limited to manual PWM mode. Automatic -"Smart Guardian" mode control handling is not implemented. However -if you want to go for "manual mode" just write 1 to pwmN_enable. +"Smart Guardian" mode control handling is only implemented for older chips +(see below.) However if you want to go for "manual mode" just write 1 to +pwmN_enable. If you are only able to control the fan speed with very small PWM values, try lowering the PWM base frequency (pwm1_freq). Depending on the fan, it may give you a somewhat greater control range. The same frequency is used to drive all fan outputs, which is why pwm2_freq and pwm3_freq are read-only. + + +Automatic fan speed control (old interface) +------------------------------------------- + +The driver supports the old interface to automatic fan speed control +which is implemented by IT8705F chips up to revision F and IT8712F +chips up to revision G. + +This interface implements 4 temperature vs. PWM output trip points. +The PWM output of trip point 4 is always the maximum value (fan running +at full speed) while the PWM output of the other 3 trip points can be +freely chosen. The temperature of all 4 trip points can be freely chosen. +Additionally, trip point 1 has an hysteresis temperature attached, to +prevent fast switching between fan on and off. + +The chip automatically computes the PWM output value based on the input +temperature, based on this simple rule: if the temperature value is +between trip point N and trip point N+1 then the PWM output value is +the one of trip point N. The automatic control mode is less flexible +than the manual control mode, but it reacts faster, is more robust and +doesn't use CPU cycles. + +Trip points must be set properly before switching to automatic fan speed +control mode. The driver will perform basic integrity checks before +actually switching to automatic control mode. diff --git a/Documentation/hwmon/lm90 b/Documentation/hwmon/lm90 index 93d8e3d5515..6a03dd4bcc9 100644 --- a/Documentation/hwmon/lm90 +++ b/Documentation/hwmon/lm90 @@ -84,6 +84,10 @@ Supported chips: Addresses scanned: I2C 0x4c Datasheet: Publicly available at the Maxim website http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3500 + * Winbond/Nuvoton W83L771AWG/ASG + Prefix: 'w83l771' + Addresses scanned: I2C 0x4c + Datasheet: Not publicly available, can be requested from Nuvoton Author: Jean Delvare <khali@linux-fr.org> @@ -147,6 +151,12 @@ MAX6680 and MAX6681: * Selectable address * Remote sensor type selection +W83L771AWG/ASG + * The AWG and ASG variants only differ in package format. + * Filter and alert configuration register at 0xBF + * Diode ideality factor configuration (remote sensor) at 0xE3 + * Moving average (depending on conversion rate) + All temperature values are given in degrees Celsius. Resolution is 1.0 degree for the local temperature, 0.125 degree for the remote temperature, except for the MAX6657, MAX6658 and MAX6659 which have a @@ -163,6 +173,18 @@ The lm90 driver will not update its values more frequently than every other second; reading them more often will do no harm, but will return 'old' values. +SMBus Alert Support +------------------- + +This driver has basic support for SMBus alert. When an alert is received, +the status register is read and the faulty temperature channel is logged. + +The Analog Devices chips (ADM1032 and ADT7461) do not implement the SMBus +alert protocol properly so additional care is needed: the ALERT output is +disabled when an alert is received, and is re-enabled only when the alarm +is gone. Otherwise the chip would block alerts from other chips in the bus +as long as the alarm is active. + PEC Support ----------- diff --git a/Documentation/init.txt b/Documentation/init.txt new file mode 100644 index 00000000000..535ad5e82b9 --- /dev/null +++ b/Documentation/init.txt @@ -0,0 +1,49 @@ +Explaining the dreaded "No init found." boot hang message +========================================================= + +OK, so you've got this pretty unintuitive message (currently located +in init/main.c) and are wondering what the H*** went wrong. +Some high-level reasons for failure (listed roughly in order of execution) +to load the init binary are: +A) Unable to mount root FS +B) init binary doesn't exist on rootfs +C) broken console device +D) binary exists but dependencies not available +E) binary cannot be loaded + +Detailed explanations: +0) Set "debug" kernel parameter (in bootloader config file or CONFIG_CMDLINE) + to get more detailed kernel messages. +A) make sure you have the correct root FS type + (and root= kernel parameter points to the correct partition), + required drivers such as storage hardware (such as SCSI or USB!) + and filesystem (ext3, jffs2 etc.) are builtin (alternatively as modules, + to be pre-loaded by an initrd) +C) Possibly a conflict in console= setup --> initial console unavailable. + E.g. some serial consoles are unreliable due to serial IRQ issues (e.g. + missing interrupt-based configuration). + Try using a different console= device or e.g. netconsole= . +D) e.g. required library dependencies of the init binary such as + /lib/ld-linux.so.2 missing or broken. Use readelf -d <INIT>|grep NEEDED + to find out which libraries are required. +E) make sure the binary's architecture matches your hardware. + E.g. i386 vs. x86_64 mismatch, or trying to load x86 on ARM hardware. + In case you tried loading a non-binary file here (shell script?), + you should make sure that the script specifies an interpreter in its shebang + header line (#!/...) that is fully working (including its library + dependencies). And before tackling scripts, better first test a simple + non-script binary such as /bin/sh and confirm its successful execution. + To find out more, add code to init/main.c to display kernel_execve()s + return values. + +Please extend this explanation whenever you find new failure causes +(after all loading the init binary is a CRITICAL and hard transition step +which needs to be made as painless as possible), then submit patch to LKML. +Further TODOs: +- Implement the various run_init_process() invocations via a struct array + which can then store the kernel_execve() result value and on failure + log it all by iterating over _all_ results (very important usability fix). +- try to make the implementation itself more helpful in general, + e.g. by providing additional error messages at affected places. + +Andreas Mohr <andi at lisas period de> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index d80930d58da..3bc48b0bd3a 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2834,6 +2834,12 @@ and is between 256 and 4096 characters. It is defined in the file default x2apic cluster mode on platforms supporting x2apic. + x86_mrst_timer= [X86-32,APBT] + Choose timer option for x86 Moorestown MID platform. + Two valid options are apbt timer only and lapic timer + plus one apbt timer for broadcast timer. + x86_mrst_timer=apbt_only | lapic_and_apbt + xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks. xd_geo= See header of drivers/block/xd.c. diff --git a/Documentation/kprobes.txt b/Documentation/kprobes.txt index 053037a1fe6..2f9115c0ae6 100644 --- a/Documentation/kprobes.txt +++ b/Documentation/kprobes.txt @@ -1,6 +1,7 @@ Title : Kernel Probes (Kprobes) Authors : Jim Keniston <jkenisto@us.ibm.com> - : Prasanna S Panchamukhi <prasanna@in.ibm.com> + : Prasanna S Panchamukhi <prasanna.panchamukhi@gmail.com> + : Masami Hiramatsu <mhiramat@redhat.com> CONTENTS @@ -15,6 +16,7 @@ CONTENTS 9. Jprobes Example 10. Kretprobes Example Appendix A: The kprobes debugfs interface +Appendix B: The kprobes sysctl interface 1. Concepts: Kprobes, Jprobes, Return Probes @@ -42,13 +44,13 @@ registration/unregistration of a group of *probes. These functions can speed up unregistration process when you have to unregister a lot of probes at once. -The next three subsections explain how the different types of -probes work. They explain certain things that you'll need to -know in order to make the best use of Kprobes -- e.g., the -difference between a pre_handler and a post_handler, and how -to use the maxactive and nmissed fields of a kretprobe. But -if you're in a hurry to start using Kprobes, you can skip ahead -to section 2. +The next four subsections explain how the different types of +probes work and how jump optimization works. They explain certain +things that you'll need to know in order to make the best use of +Kprobes -- e.g., the difference between a pre_handler and +a post_handler, and how to use the maxactive and nmissed fields of +a kretprobe. But if you're in a hurry to start using Kprobes, you +can skip ahead to section 2. 1.1 How Does a Kprobe Work? @@ -161,13 +163,125 @@ In case probed function is entered but there is no kretprobe_instance object available, then in addition to incrementing the nmissed count, the user entry_handler invocation is also skipped. +1.4 How Does Jump Optimization Work? + +If you configured your kernel with CONFIG_OPTPROBES=y (currently +this option is supported on x86/x86-64, non-preemptive kernel) and +the "debug.kprobes_optimization" kernel parameter is set to 1 (see +sysctl(8)), Kprobes tries to reduce probe-hit overhead by using a jump +instruction instead of a breakpoint instruction at each probepoint. + +1.4.1 Init a Kprobe + +When a probe is registered, before attempting this optimization, +Kprobes inserts an ordinary, breakpoint-based kprobe at the specified +address. So, even if it's not possible to optimize this particular +probepoint, there'll be a probe there. + +1.4.2 Safety Check + +Before optimizing a probe, Kprobes performs the following safety checks: + +- Kprobes verifies that the region that will be replaced by the jump +instruction (the "optimized region") lies entirely within one function. +(A jump instruction is multiple bytes, and so may overlay multiple +instructions.) + +- Kprobes analyzes the entire function and verifies that there is no +jump into the optimized region. Specifically: + - the function contains no indirect jump; + - the function contains no instruction that causes an exception (since + the fixup code triggered by the exception could jump back into the + optimized region -- Kprobes checks the exception tables to verify this); + and + - there is no near jump to the optimized region (other than to the first + byte). + +- For each instruction in the optimized region, Kprobes verifies that +the instruction can be executed out of line. + +1.4.3 Preparing Detour Buffer + +Next, Kprobes prepares a "detour" buffer, which contains the following +instruction sequence: +- code to push the CPU's registers (emulating a breakpoint trap) +- a call to the trampoline code which calls user's probe handlers. +- code to restore registers +- the instructions from the optimized region +- a jump back to the original execution path. + +1.4.4 Pre-optimization + +After preparing the detour buffer, Kprobes verifies that none of the +following situations exist: +- The probe has either a break_handler (i.e., it's a jprobe) or a +post_handler. +- Other instructions in the optimized region are probed. +- The probe is disabled. +In any of the above cases, Kprobes won't start optimizing the probe. +Since these are temporary situations, Kprobes tries to start +optimizing it again if the situation is changed. + +If the kprobe can be optimized, Kprobes enqueues the kprobe to an +optimizing list, and kicks the kprobe-optimizer workqueue to optimize +it. If the to-be-optimized probepoint is hit before being optimized, +Kprobes returns control to the original instruction path by setting +the CPU's instruction pointer to the copied code in the detour buffer +-- thus at least avoiding the single-step. + +1.4.5 Optimization + +The Kprobe-optimizer doesn't insert the jump instruction immediately; +rather, it calls synchronize_sched() for safety first, because it's +possible for a CPU to be interrupted in the middle of executing the +optimized region(*). As you know, synchronize_sched() can ensure +that all interruptions that were active when synchronize_sched() +was called are done, but only if CONFIG_PREEMPT=n. So, this version +of kprobe optimization supports only kernels with CONFIG_PREEMPT=n.(**) + +After that, the Kprobe-optimizer calls stop_machine() to replace +the optimized region with a jump instruction to the detour buffer, +using text_poke_smp(). + +1.4.6 Unoptimization + +When an optimized kprobe is unregistered, disabled, or blocked by +another kprobe, it will be unoptimized. If this happens before +the optimization is complete, the kprobe is just dequeued from the +optimized list. If the optimization has been done, the jump is +replaced with the original code (except for an int3 breakpoint in +the first byte) by using text_poke_smp(). + +(*)Please imagine that the 2nd instruction is interrupted and then +the optimizer replaces the 2nd instruction with the jump *address* +while the interrupt handler is running. When the interrupt +returns to original address, there is no valid instruction, +and it causes an unexpected result. + +(**)This optimization-safety checking may be replaced with the +stop-machine method that ksplice uses for supporting a CONFIG_PREEMPT=y +kernel. + +NOTE for geeks: +The jump optimization changes the kprobe's pre_handler behavior. +Without optimization, the pre_handler can change the kernel's execution +path by changing regs->ip and returning 1. However, when the probe +is optimized, that modification is ignored. Thus, if you want to +tweak the kernel's execution path, you need to suppress optimization, +using one of the following techniques: +- Specify an empty function for the kprobe's post_handler or break_handler. + or +- Config CONFIG_OPTPROBES=n. + or +- Execute 'sysctl -w debug.kprobes_optimization=n' + 2. Architectures Supported Kprobes, jprobes, and return probes are implemented on the following architectures: -- i386 -- x86_64 (AMD-64, EM64T) +- i386 (Supports jump optimization) +- x86_64 (AMD-64, EM64T) (Supports jump optimization) - ppc64 - ia64 (Does not support probes on instruction slot1.) - sparc64 (Return probes not yet implemented.) @@ -193,6 +307,10 @@ it useful to "Compile the kernel with debug info" (CONFIG_DEBUG_INFO), so you can use "objdump -d -l vmlinux" to see the source-to-object code mapping. +If you want to reduce probing overhead, set "Kprobes jump optimization +support" (CONFIG_OPTPROBES) to "y". You can find this option under the +"Kprobes" line. + 4. API Reference The Kprobes API includes a "register" function and an "unregister" @@ -389,7 +507,10 @@ the probe which has been registered. Kprobes allows multiple probes at the same address. Currently, however, there cannot be multiple jprobes on the same function at -the same time. +the same time. Also, a probepoint for which there is a jprobe or +a post_handler cannot be optimized. So if you install a jprobe, +or a kprobe with a post_handler, at an optimized probepoint, the +probepoint will be unoptimized automatically. In general, you can install a probe anywhere in the kernel. In particular, you can probe interrupt handlers. Known exceptions @@ -453,6 +574,38 @@ reason, Kprobes doesn't support return probes (or kprobes or jprobes) on the x86_64 version of __switch_to(); the registration functions return -EINVAL. +On x86/x86-64, since the Jump Optimization of Kprobes modifies +instructions widely, there are some limitations to optimization. To +explain it, we introduce some terminology. Imagine a 3-instruction +sequence consisting of a two 2-byte instructions and one 3-byte +instruction. + + IA + | +[-2][-1][0][1][2][3][4][5][6][7] + [ins1][ins2][ ins3 ] + [<- DCR ->] + [<- JTPR ->] + +ins1: 1st Instruction +ins2: 2nd Instruction +ins3: 3rd Instruction +IA: Insertion Address +JTPR: Jump Target Prohibition Region +DCR: Detoured Code Region + +The instructions in DCR are copied to the out-of-line buffer +of the kprobe, because the bytes in DCR are replaced by +a 5-byte jump instruction. So there are several limitations. + +a) The instructions in DCR must be relocatable. +b) The instructions in DCR must not include a call instruction. +c) JTPR must not be targeted by any jump or call instruction. +d) DCR must not straddle the border betweeen functions. + +Anyway, these limitations are checked by the in-kernel instruction +decoder, so you don't need to worry about that. + 6. Probe Overhead On a typical CPU in use in 2005, a kprobe hit takes 0.5 to 1.0 @@ -476,6 +629,19 @@ k = 0.49 usec; j = 0.76; r = 0.80; kr = 0.82; jr = 1.07 ppc64: POWER5 (gr), 1656 MHz (SMT disabled, 1 virtual CPU per physical CPU) k = 0.77 usec; j = 1.31; r = 1.26; kr = 1.45; jr = 1.99 +6.1 Optimized Probe Overhead + +Typically, an optimized kprobe hit takes 0.07 to 0.1 microseconds to +process. Here are sample overhead figures (in usec) for x86 architectures. +k = unoptimized kprobe, b = boosted (single-step skipped), o = optimized kprobe, +r = unoptimized kretprobe, rb = boosted kretprobe, ro = optimized kretprobe. + +i386: Intel(R) Xeon(R) E5410, 2.33GHz, 4656.90 bogomips +k = 0.80 usec; b = 0.33; o = 0.05; r = 1.10; rb = 0.61; ro = 0.33 + +x86-64: Intel(R) Xeon(R) E5410, 2.33GHz, 4656.90 bogomips +k = 0.99 usec; b = 0.43; o = 0.06; r = 1.24; rb = 0.68; ro = 0.30 + 7. TODO a. SystemTap (http://sourceware.org/systemtap): Provides a simplified @@ -523,7 +689,8 @@ is also specified. Following columns show probe status. If the probe is on a virtual address that is no longer valid (module init sections, module virtual addresses that correspond to modules that've been unloaded), such probes are marked with [GONE]. If the probe is temporarily disabled, -such probes are marked with [DISABLED]. +such probes are marked with [DISABLED]. If the probe is optimized, it is +marked with [OPTIMIZED]. /sys/kernel/debug/kprobes/enabled: Turn kprobes ON/OFF forcibly. @@ -533,3 +700,19 @@ registered probes will be disarmed, till such time a "1" is echoed to this file. Note that this knob just disarms and arms all kprobes and doesn't change each probe's disabling state. This means that disabled kprobes (marked [DISABLED]) will be not enabled if you turn ON all kprobes by this knob. + + +Appendix B: The kprobes sysctl interface + +/proc/sys/debug/kprobes-optimization: Turn kprobes optimization ON/OFF. + +When CONFIG_OPTPROBES=y, this sysctl interface appears and it provides +a knob to globally and forcibly turn jump optimization (see section +1.4) ON or OFF. By default, jump optimization is allowed (ON). +If you echo "0" to this file or set "debug.kprobes_optimization" to +0 via sysctl, all optimized probes will be unoptimized, and any new +probes registered after that will not be optimized. Note that this +knob *changes* the optimized state. This means that optimized probes +(marked [OPTIMIZED]) will be unoptimized ([OPTIMIZED] tag will be +removed). If the knob is turned on, they will be optimized again. + diff --git a/Documentation/kvm/api.txt b/Documentation/kvm/api.txt index 2811e452f75..c6416a39816 100644 --- a/Documentation/kvm/api.txt +++ b/Documentation/kvm/api.txt @@ -23,12 +23,12 @@ of a virtual machine. The ioctls belong to three classes Only run vcpu ioctls from the same thread that was used to create the vcpu. -2. File descritpors +2. File descriptors The kvm API is centered around file descriptors. An initial open("/dev/kvm") obtains a handle to the kvm subsystem; this handle can be used to issue system ioctls. A KVM_CREATE_VM ioctl on this -handle will create a VM file descripror which can be used to issue VM +handle will create a VM file descriptor which can be used to issue VM ioctls. A KVM_CREATE_VCPU ioctl on a VM fd will create a virtual cpu and return a file descriptor pointing to it. Finally, ioctls on a vcpu fd can be used to control the vcpu, including the important task of @@ -643,7 +643,7 @@ Type: vm ioctl Parameters: struct kvm_clock_data (in) Returns: 0 on success, -1 on error -Sets the current timestamp of kvmclock to the valued specific in its parameter. +Sets the current timestamp of kvmclock to the value specified in its parameter. In conjunction with KVM_GET_CLOCK, it is used to ensure monotonicity on scenarios such as migration. @@ -795,11 +795,11 @@ Unused. __u64 data_offset; /* relative to kvm_run start */ } io; -If exit_reason is KVM_EXIT_IO_IN or KVM_EXIT_IO_OUT, then the vcpu has +If exit_reason is KVM_EXIT_IO, then the vcpu has executed a port I/O instruction which could not be satisfied by kvm. data_offset describes where the data is located (KVM_EXIT_IO_OUT) or where kvm expects application code to place the data for the next -KVM_RUN invocation (KVM_EXIT_IO_IN). Data format is a patcked array. +KVM_RUN invocation (KVM_EXIT_IO_IN). Data format is a packed array. struct { struct kvm_debug_exit_arch arch; @@ -815,7 +815,7 @@ Unused. __u8 is_write; } mmio; -If exit_reason is KVM_EXIT_MMIO or KVM_EXIT_IO_OUT, then the vcpu has +If exit_reason is KVM_EXIT_MMIO, then the vcpu has executed a memory-mapped I/O instruction which could not be satisfied by kvm. The 'data' member contains the written data if 'is_write' is true, and should be filled by application code otherwise. diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt index 356fd86f4ea..ab00eeddeca 100644 --- a/Documentation/power/runtime_pm.txt +++ b/Documentation/power/runtime_pm.txt @@ -224,6 +224,12 @@ defined in include/linux/pm.h: RPM_SUSPENDED, which means that each device is initially regarded by the PM core as 'suspended', regardless of its real hardware status + unsigned int runtime_auto; + - if set, indicates that the user space has allowed the device driver to + power manage the device at run time via the /sys/devices/.../power/control + interface; it may only be modified with the help of the pm_runtime_allow() + and pm_runtime_forbid() helper functions + All of the above fields are members of the 'power' member of 'struct device'. 4. Run-time PM Device Helper Functions @@ -329,6 +335,20 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h: 'power.runtime_error' is set or 'power.disable_depth' is greater than zero) + bool pm_runtime_suspended(struct device *dev); + - return true if the device's runtime PM status is 'suspended', or false + otherwise + + void pm_runtime_allow(struct device *dev); + - set the power.runtime_auto flag for the device and decrease its usage + counter (used by the /sys/devices/.../power/control interface to + effectively allow the device to be power managed at run time) + + void pm_runtime_forbid(struct device *dev); + - unset the power.runtime_auto flag for the device and increase its usage + counter (used by the /sys/devices/.../power/control interface to + effectively prevent the device from being power managed at run time) + It is safe to execute the following helper functions from interrupt context: pm_request_idle() @@ -382,6 +402,18 @@ may be desirable to suspend the device as soon as ->probe() or ->remove() has finished, so the PM core uses pm_runtime_idle_sync() to invoke the subsystem-level idle callback for the device at that time. +The user space can effectively disallow the driver of the device to power manage +it at run time by changing the value of its /sys/devices/.../power/control +attribute to "on", which causes pm_runtime_forbid() to be called. In principle, +this mechanism may also be used by the driver to effectively turn off the +run-time power management of the device until the user space turns it on. +Namely, during the initialization the driver can make sure that the run-time PM +status of the device is 'active' and call pm_runtime_forbid(). It should be +noted, however, that if the user space has already intentionally changed the +value of /sys/devices/.../power/control to "auto" to allow the driver to power +manage the device at run time, the driver may confuse it by using +pm_runtime_forbid() this way. + 6. Run-time PM and System Sleep Run-time PM and system sleep (i.e., system suspend and hibernation, also known @@ -431,3 +463,64 @@ The PM core always increments the run-time usage counter before calling the ->prepare() callback and decrements it after calling the ->complete() callback. Hence disabling run-time PM temporarily like this will not cause any run-time suspend callbacks to be lost. + +7. Generic subsystem callbacks + +Subsystems may wish to conserve code space by using the set of generic power +management callbacks provided by the PM core, defined in +driver/base/power/generic_ops.c: + + int pm_generic_runtime_idle(struct device *dev); + - invoke the ->runtime_idle() callback provided by the driver of this + device, if defined, and call pm_runtime_suspend() for this device if the + return value is 0 or the callback is not defined + + int pm_generic_runtime_suspend(struct device *dev); + - invoke the ->runtime_suspend() callback provided by the driver of this + device and return its result, or return -EINVAL if not defined + + int pm_generic_runtime_resume(struct device *dev); + - invoke the ->runtime_resume() callback provided by the driver of this + device and return its result, or return -EINVAL if not defined + + int pm_generic_suspend(struct device *dev); + - if the device has not been suspended at run time, invoke the ->suspend() + callback provided by its driver and return its result, or return 0 if not + defined + + int pm_generic_resume(struct device *dev); + - invoke the ->resume() callback provided by the driver of this device and, + if successful, change the device's runtime PM status to 'active' + + int pm_generic_freeze(struct device *dev); + - if the device has not been suspended at run time, invoke the ->freeze() + callback provided by its driver and return its result, or return 0 if not + defined + + int pm_generic_thaw(struct device *dev); + - if the device has not been suspended at run time, invoke the ->thaw() + callback provided by its driver and return its result, or return 0 if not + defined + + int pm_generic_poweroff(struct device *dev); + - if the device has not been suspended at run time, invoke the ->poweroff() + callback provided by its driver and return its result, or return 0 if not + defined + + int pm_generic_restore(struct device *dev); + - invoke the ->restore() callback provided by the driver of this device and, + if successful, change the device's runtime PM status to 'active' + +These functions can be assigned to the ->runtime_idle(), ->runtime_suspend(), +->runtime_resume(), ->suspend(), ->resume(), ->freeze(), ->thaw(), ->poweroff(), +or ->restore() callback pointers in the subsystem-level dev_pm_ops structures. + +If a subsystem wishes to use all of them at the same time, it can simply assign +the GENERIC_SUBSYS_PM_OPS macro, defined in include/linux/pm.h, to its +dev_pm_ops structure pointer. + +Device drivers that wish to use the same function as a system suspend, freeze, +poweroff and run-time suspend callback, and similarly for system resume, thaw, +restore, and run-time resume, can achieve this with the help of the +UNIVERSAL_DEV_PM_OPS macro defined in include/linux/pm.h (possibly setting its +last argument to NULL). diff --git a/Documentation/powerpc/dts-bindings/fsl/dma.txt b/Documentation/powerpc/dts-bindings/fsl/dma.txt index 0732cdd05ba..2a4b4bce611 100644 --- a/Documentation/powerpc/dts-bindings/fsl/dma.txt +++ b/Documentation/powerpc/dts-bindings/fsl/dma.txt @@ -44,21 +44,29 @@ Example: compatible = "fsl,mpc8349-dma-channel", "fsl,elo-dma-channel"; cell-index = <0>; reg = <0 0x80>; + interrupt-parent = <&ipic>; + interrupts = <71 8>; }; dma-channel@80 { compatible = "fsl,mpc8349-dma-channel", "fsl,elo-dma-channel"; cell-index = <1>; reg = <0x80 0x80>; + interrupt-parent = <&ipic>; + interrupts = <71 8>; }; dma-channel@100 { compatible = "fsl,mpc8349-dma-channel", "fsl,elo-dma-channel"; cell-index = <2>; reg = <0x100 0x80>; + interrupt-parent = <&ipic>; + interrupts = <71 8>; }; dma-channel@180 { compatible = "fsl,mpc8349-dma-channel", "fsl,elo-dma-channel"; cell-index = <3>; reg = <0x180 0x80>; + interrupt-parent = <&ipic>; + interrupts = <71 8>; }; }; diff --git a/Documentation/powerpc/dts-bindings/fsl/i2c.txt b/Documentation/powerpc/dts-bindings/fsl/i2c.txt index b6d2e21474f..50da2031058 100644 --- a/Documentation/powerpc/dts-bindings/fsl/i2c.txt +++ b/Documentation/powerpc/dts-bindings/fsl/i2c.txt @@ -2,15 +2,14 @@ Required properties : - - device_type : Should be "i2c" - reg : Offset and length of the register set for the device + - compatible : should be "fsl,CHIP-i2c" where CHIP is the name of a + compatible processor, e.g. mpc8313, mpc8543, mpc8544, mpc5121, + mpc5200 or mpc5200b. For the mpc5121, an additional node + "fsl,mpc5121-i2c-ctrl" is required as shown in the example below. Recommended properties : - - compatible : compatibility list with 2 entries, the first should - be "fsl,CHIP-i2c" where CHIP is the name of a compatible processor, - e.g. mpc8313, mpc8543, mpc8544, mpc5200 or mpc5200b. The second one - should be "fsl-i2c". - interrupts : <a b> where a is the interrupt number and b is a field that represents an encoding of the sense and level information for the interrupt. This should be encoded based on @@ -24,25 +23,40 @@ Recommended properties : Examples : + /* MPC5121 based board */ + i2c@1740 { + #address-cells = <1>; + #size-cells = <0>; + compatible = "fsl,mpc5121-i2c", "fsl-i2c"; + reg = <0x1740 0x20>; + interrupts = <11 0x8>; + interrupt-parent = <&ipic>; + clock-frequency = <100000>; + }; + + i2ccontrol@1760 { + compatible = "fsl,mpc5121-i2c-ctrl"; + reg = <0x1760 0x8>; + }; + + /* MPC5200B based board */ i2c@3d00 { #address-cells = <1>; #size-cells = <0>; compatible = "fsl,mpc5200b-i2c","fsl,mpc5200-i2c","fsl-i2c"; - cell-index = <0>; reg = <0x3d00 0x40>; interrupts = <2 15 0>; interrupt-parent = <&mpc5200_pic>; fsl,preserve-clocking; }; + /* MPC8544 base board */ i2c@3100 { #address-cells = <1>; #size-cells = <0>; - cell-index = <1>; compatible = "fsl,mpc8544-i2c", "fsl-i2c"; reg = <0x3100 0x100>; interrupts = <43 2>; interrupt-parent = <&mpic>; clock-frequency = <400000>; }; - diff --git a/Documentation/vm/slub.txt b/Documentation/vm/slub.txt index b37300edf27..07375e73981 100644 --- a/Documentation/vm/slub.txt +++ b/Documentation/vm/slub.txt @@ -41,6 +41,7 @@ Possible debug options are P Poisoning (object and padding) U User tracking (free and alloc) T Trace (please only use on single slabs) + A Toggle failslab filter mark for the cache O Switch debugging off for caches that would have caused higher minimum slab orders - Switch all debugging off (useful if the kernel is |