diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/device-mapper/dm-log.txt | 54 | ||||
| -rw-r--r-- | Documentation/device-mapper/dm-queue-length.txt | 39 | ||||
| -rw-r--r-- | Documentation/device-mapper/dm-service-time.txt | 91 | ||||
| -rw-r--r-- | Documentation/filesystems/Locking | 43 | ||||
| -rw-r--r-- | Documentation/kernel-parameters.txt | 10 | ||||
| -rw-r--r-- | Documentation/laptops/thinkpad-acpi.txt | 47 |
6 files changed, 244 insertions, 40 deletions
diff --git a/Documentation/device-mapper/dm-log.txt b/Documentation/device-mapper/dm-log.txt new file mode 100644 index 00000000000..994dd75475a --- /dev/null +++ b/Documentation/device-mapper/dm-log.txt @@ -0,0 +1,54 @@ +Device-Mapper Logging +===================== +The device-mapper logging code is used by some of the device-mapper +RAID targets to track regions of the disk that are not consistent. +A region (or portion of the address space) of the disk may be +inconsistent because a RAID stripe is currently being operated on or +a machine died while the region was being altered. In the case of +mirrors, a region would be considered dirty/inconsistent while you +are writing to it because the writes need to be replicated for all +the legs of the mirror and may not reach the legs at the same time. +Once all writes are complete, the region is considered clean again. + +There is a generic logging interface that the device-mapper RAID +implementations use to perform logging operations (see +dm_dirty_log_type in include/linux/dm-dirty-log.h). Various different +logging implementations are available and provide different +capabilities. The list includes: + +Type Files +==== ===== +disk drivers/md/dm-log.c +core drivers/md/dm-log.c +userspace drivers/md/dm-log-userspace* include/linux/dm-log-userspace.h + +The "disk" log type +------------------- +This log implementation commits the log state to disk. This way, the +logging state survives reboots/crashes. + +The "core" log type +------------------- +This log implementation keeps the log state in memory. The log state +will not survive a reboot or crash, but there may be a small boost in +performance. This method can also be used if no storage device is +available for storing log state. + +The "userspace" log type +------------------------ +This log type simply provides a way to export the log API to userspace, +so log implementations can be done there. This is done by forwarding most +logging requests to userspace, where a daemon receives and processes the +request. + +The structure used for communication between kernel and userspace are +located in include/linux/dm-log-userspace.h. Due to the frequency, +diversity, and 2-way communication nature of the exchanges between +kernel and userspace, 'connector' is used as the interface for +communication. + +There are currently two userspace log implementations that leverage this +framework - "clustered_disk" and "clustered_core". These implementations +provide a cluster-coherent log for shared-storage. Device-mapper mirroring +can be used in a shared-storage environment when the cluster log implementations +are employed. diff --git a/Documentation/device-mapper/dm-queue-length.txt b/Documentation/device-mapper/dm-queue-length.txt new file mode 100644 index 00000000000..f4db2562175 --- /dev/null +++ b/Documentation/device-mapper/dm-queue-length.txt @@ -0,0 +1,39 @@ +dm-queue-length +=============== + +dm-queue-length is a path selector module for device-mapper targets, +which selects a path with the least number of in-flight I/Os. +The path selector name is 'queue-length'. + +Table parameters for each path: [<repeat_count>] + <repeat_count>: The number of I/Os to dispatch using the selected + path before switching to the next path. + If not given, internal default is used. To check + the default value, see the activated table. + +Status for each path: <status> <fail-count> <in-flight> + <status>: 'A' if the path is active, 'F' if the path is failed. + <fail-count>: The number of path failures. + <in-flight>: The number of in-flight I/Os on the path. + + +Algorithm +========= + +dm-queue-length increments/decrements 'in-flight' when an I/O is +dispatched/completed respectively. +dm-queue-length selects a path with the minimum 'in-flight'. + + +Examples +======== +In case that 2 paths (sda and sdb) are used with repeat_count == 128. + +# echo "0 10 multipath 0 0 1 1 queue-length 0 2 1 8:0 128 8:16 128" \ + dmsetup create test +# +# dmsetup table +test: 0 10 multipath 0 0 1 1 queue-length 0 2 1 8:0 128 8:16 128 +# +# dmsetup status +test: 0 10 multipath 2 0 0 0 1 1 E 0 2 1 8:0 A 0 0 8:16 A 0 0 diff --git a/Documentation/device-mapper/dm-service-time.txt b/Documentation/device-mapper/dm-service-time.txt new file mode 100644 index 00000000000..7d00668e97b --- /dev/null +++ b/Documentation/device-mapper/dm-service-time.txt @@ -0,0 +1,91 @@ +dm-service-time +=============== + +dm-service-time is a path selector module for device-mapper targets, +which selects a path with the shortest estimated service time for +the incoming I/O. + +The service time for each path is estimated by dividing the total size +of in-flight I/Os on a path with the performance value of the path. +The performance value is a relative throughput value among all paths +in a path-group, and it can be specified as a table argument. + +The path selector name is 'service-time'. + +Table parameters for each path: [<repeat_count> [<relative_throughput>]] + <repeat_count>: The number of I/Os to dispatch using the selected + path before switching to the next path. + If not given, internal default is used. To check + the default value, see the activated table. + <relative_throughput>: The relative throughput value of the path + among all paths in the path-group. + The valid range is 0-100. + If not given, minimum value '1' is used. + If '0' is given, the path isn't selected while + other paths having a positive value are available. + +Status for each path: <status> <fail-count> <in-flight-size> \ + <relative_throughput> + <status>: 'A' if the path is active, 'F' if the path is failed. + <fail-count>: The number of path failures. + <in-flight-size>: The size of in-flight I/Os on the path. + <relative_throughput>: The relative throughput value of the path + among all paths in the path-group. + + +Algorithm +========= + +dm-service-time adds the I/O size to 'in-flight-size' when the I/O is +dispatched and substracts when completed. +Basically, dm-service-time selects a path having minimum service time +which is calculated by: + + ('in-flight-size' + 'size-of-incoming-io') / 'relative_throughput' + +However, some optimizations below are used to reduce the calculation +as much as possible. + + 1. If the paths have the same 'relative_throughput', skip + the division and just compare the 'in-flight-size'. + + 2. If the paths have the same 'in-flight-size', skip the division + and just compare the 'relative_throughput'. + + 3. If some paths have non-zero 'relative_throughput' and others + have zero 'relative_throughput', ignore those paths with zero + 'relative_throughput'. + +If such optimizations can't be applied, calculate service time, and +compare service time. +If calculated service time is equal, the path having maximum +'relative_throughput' may be better. So compare 'relative_throughput' +then. + + +Examples +======== +In case that 2 paths (sda and sdb) are used with repeat_count == 128 +and sda has an average throughput 1GB/s and sdb has 4GB/s, +'relative_throughput' value may be '1' for sda and '4' for sdb. + +# echo "0 10 multipath 0 0 1 1 service-time 0 2 2 8:0 128 1 8:16 128 4" \ + dmsetup create test +# +# dmsetup table +test: 0 10 multipath 0 0 1 1 service-time 0 2 2 8:0 128 1 8:16 128 4 +# +# dmsetup status +test: 0 10 multipath 2 0 0 0 1 1 E 0 2 2 8:0 A 0 0 1 8:16 A 0 0 4 + + +Or '2' for sda and '8' for sdb would be also true. + +# echo "0 10 multipath 0 0 1 1 service-time 0 2 2 8:0 128 2 8:16 128 8" \ + dmsetup create test +# +# dmsetup table +test: 0 10 multipath 0 0 1 1 service-time 0 2 2 8:0 128 2 8:16 128 8 +# +# dmsetup status +test: 0 10 multipath 2 0 0 0 1 1 E 0 2 2 8:0 A 0 0 2 8:16 A 0 0 8 diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index 229d7b7c50a..18b9d0ca063 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -109,27 +109,28 @@ prototypes: locking rules: All may block. - BKL s_lock s_umount -alloc_inode: no no no -destroy_inode: no -dirty_inode: no (must not sleep) -write_inode: no -drop_inode: no !!!inode_lock!!! -delete_inode: no -put_super: yes yes no -write_super: no yes read -sync_fs: no no read -freeze_fs: ? -unfreeze_fs: ? -statfs: no no no -remount_fs: yes yes maybe (see below) -clear_inode: no -umount_begin: yes no no -show_options: no (vfsmount->sem) -quota_read: no no no (see below) -quota_write: no no no (see below) - -->remount_fs() will have the s_umount lock if it's already mounted. + None have BKL + s_umount +alloc_inode: +destroy_inode: +dirty_inode: (must not sleep) +write_inode: +drop_inode: !!!inode_lock!!! +delete_inode: +put_super: write +write_super: read +sync_fs: read +freeze_fs: read +unfreeze_fs: read +statfs: no +remount_fs: maybe (see below) +clear_inode: +umount_begin: no +show_options: no (namespace_sem) +quota_read: no (see below) +quota_write: no (see below) + +->remount_fs() will have the s_umount exclusive lock if it's already mounted. When called from get_sb_single, it does NOT have the s_umount lock. ->quota_read() and ->quota_write() functions are both guaranteed to be the only ones operating on the quota file by the quota code (via diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 92e1ab8178a..d08759aa090 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -229,14 +229,6 @@ and is between 256 and 4096 characters. It is defined in the file to assume that this machine's pmtimer latches its value and always returns good values. - acpi.power_nocheck= [HW,ACPI] - Format: 1/0 enable/disable the check of power state. - On some bogus BIOS the _PSC object/_STA object of - power resource can't return the correct device power - state. In such case it is unneccessary to check its - power state again in power transition. - 1 : disable the power state check - acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode Format: { level | edge | high | low } @@ -1863,7 +1855,7 @@ and is between 256 and 4096 characters. It is defined in the file IRQ routing is enabled. noacpi [X86] Do not use ACPI for IRQ routing or for PCI scanning. - nocrs [X86] Don't use _CRS for PCI resource + use_crs [X86] Use _CRS for PCI resource allocation. routeirq Do IRQ routing for all PCI devices. This is normally done in pci_enable_device(), diff --git a/Documentation/laptops/thinkpad-acpi.txt b/Documentation/laptops/thinkpad-acpi.txt index 78e354b42f6..f2296ecedb8 100644 --- a/Documentation/laptops/thinkpad-acpi.txt +++ b/Documentation/laptops/thinkpad-acpi.txt @@ -920,7 +920,7 @@ The available commands are: echo '<LED number> off' >/proc/acpi/ibm/led echo '<LED number> blink' >/proc/acpi/ibm/led -The <LED number> range is 0 to 7. The set of LEDs that can be +The <LED number> range is 0 to 15. The set of LEDs that can be controlled varies from model to model. Here is the common ThinkPad mapping: @@ -932,6 +932,11 @@ mapping: 5 - UltraBase battery slot 6 - (unknown) 7 - standby + 8 - dock status 1 + 9 - dock status 2 + 10, 11 - (unknown) + 12 - thinkvantage + 13, 14, 15 - (unknown) All of the above can be turned on and off and can be made to blink. @@ -940,10 +945,12 @@ sysfs notes: The ThinkPad LED sysfs interface is described in detail by the LED class documentation, in Documentation/leds-class.txt. -The leds are named (in LED ID order, from 0 to 7): +The LEDs are named (in LED ID order, from 0 to 12): "tpacpi::power", "tpacpi:orange:batt", "tpacpi:green:batt", "tpacpi::dock_active", "tpacpi::bay_active", "tpacpi::dock_batt", -"tpacpi::unknown_led", "tpacpi::standby". +"tpacpi::unknown_led", "tpacpi::standby", "tpacpi::dock_status1", +"tpacpi::dock_status2", "tpacpi::unknown_led2", "tpacpi::unknown_led3", +"tpacpi::thinkvantage". Due to limitations in the sysfs LED class, if the status of the LED indicators cannot be read due to an error, thinkpad-acpi will report it as @@ -958,6 +965,12 @@ ThinkPad indicator LED should blink in hardware accelerated mode, use the "timer" trigger, and leave the delay_on and delay_off parameters set to zero (to request hardware acceleration autodetection). +LEDs that are known not to exist in a given ThinkPad model are not +made available through the sysfs interface. If you have a dock and you +notice there are LEDs listed for your ThinkPad that do not exist (and +are not in the dock), or if you notice that there are missing LEDs, +a report to ibm-acpi-devel@lists.sourceforge.net is appreciated. + ACPI sounds -- /proc/acpi/ibm/beep ---------------------------------- @@ -1156,17 +1169,19 @@ may not be distinct. Later Lenovo models that implement the ACPI display backlight brightness control methods have 16 levels, ranging from 0 to 15. -There are two interfaces to the firmware for direct brightness control, -EC and UCMS (or CMOS). To select which one should be used, use the -brightness_mode module parameter: brightness_mode=1 selects EC mode, -brightness_mode=2 selects UCMS mode, brightness_mode=3 selects EC -mode with NVRAM backing (so that brightness changes are remembered -across shutdown/reboot). +For IBM ThinkPads, there are two interfaces to the firmware for direct +brightness control, EC and UCMS (or CMOS). To select which one should be +used, use the brightness_mode module parameter: brightness_mode=1 selects +EC mode, brightness_mode=2 selects UCMS mode, brightness_mode=3 selects EC +mode with NVRAM backing (so that brightness changes are remembered across +shutdown/reboot). The driver tries to select which interface to use from a table of defaults for each ThinkPad model. If it makes a wrong choice, please report this as a bug, so that we can fix it. +Lenovo ThinkPads only support brightness_mode=2 (UCMS). + When display backlight brightness controls are available through the standard ACPI interface, it is best to use it instead of this direct ThinkPad-specific interface. The driver will disable its native @@ -1254,7 +1269,7 @@ Fan control and monitoring: fan speed, fan enable/disable procfs: /proc/acpi/ibm/fan sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1, - pwm1_enable + pwm1_enable, fan2_input sysfs hwmon driver attributes: fan_watchdog NOTE NOTE NOTE: fan control operations are disabled by default for @@ -1267,6 +1282,9 @@ from the hardware registers of the embedded controller. This is known to work on later R, T, X and Z series ThinkPads but may show a bogus value on other models. +Some Lenovo ThinkPads support a secondary fan. This fan cannot be +controlled separately, it shares the main fan control. + Fan levels: Most ThinkPad fans work in "levels" at the firmware interface. Level 0 @@ -1397,6 +1415,11 @@ hwmon device attribute fan1_input: which can take up to two minutes. May return rubbish on older ThinkPads. +hwmon device attribute fan2_input: + Fan tachometer reading, in RPM, for the secondary fan. + Available only on some ThinkPads. If the secondary fan is + not installed, will always read 0. + hwmon driver attribute fan_watchdog: Fan safety watchdog timer interval, in seconds. Minimum is 1 second, maximum is 120 seconds. 0 disables the watchdog. @@ -1555,3 +1578,7 @@ Sysfs interface changelog: 0x020300: hotkey enable/disable support removed, attributes hotkey_bios_enabled and hotkey_enable deprecated and marked for removal. + +0x020400: Marker for 16 LEDs support. Also, LEDs that are known + to not exist in a given model are not registered with + the LED sysfs class anymore. |