diff options
Diffstat (limited to '')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-block | 273 | ||||
| -rw-r--r-- | Documentation/ABI/testing/sysfs-block-aoe | 45 | ||||
| -rw-r--r-- | Documentation/ABI/testing/sysfs-block-bcache | 156 | ||||
| -rw-r--r-- | Documentation/ABI/testing/sysfs-block-device | 58 | ||||
| -rw-r--r-- | Documentation/ABI/testing/sysfs-block-dm | 47 | ||||
| -rw-r--r-- | Documentation/ABI/testing/sysfs-block-loop | 50 | ||||
| -rw-r--r-- | Documentation/ABI/testing/sysfs-block-rssd | 5 | ||||
| -rw-r--r-- | Documentation/ABI/testing/sysfs-block-zram | 100 |
8 files changed, 734 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-block b/Documentation/ABI/testing/sysfs-block new file mode 100644 index 000000000..dea212db9 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-block @@ -0,0 +1,273 @@ +What: /sys/block/<disk>/stat +Date: February 2008 +Contact: Jerome Marchand <jmarchan@redhat.com> +Description: + The /sys/block/<disk>/stat files displays the I/O + statistics of disk <disk>. They contain 11 fields: + 1 - reads completed successfully + 2 - reads merged + 3 - sectors read + 4 - time spent reading (ms) + 5 - writes completed + 6 - writes merged + 7 - sectors written + 8 - time spent writing (ms) + 9 - I/Os currently in progress + 10 - time spent doing I/Os (ms) + 11 - weighted time spent doing I/Os (ms) + For more details refer Documentation/iostats.txt + + +What: /sys/block/<disk>/<part>/stat +Date: February 2008 +Contact: Jerome Marchand <jmarchan@redhat.com> +Description: + The /sys/block/<disk>/<part>/stat files display the + I/O statistics of partition <part>. The format is the + same as the above-written /sys/block/<disk>/stat + format. + + +What: /sys/block/<disk>/integrity/format +Date: June 2008 +Contact: Martin K. Petersen <martin.petersen@oracle.com> +Description: + Metadata format for integrity capable block device. + E.g. T10-DIF-TYPE1-CRC. + + +What: /sys/block/<disk>/integrity/read_verify +Date: June 2008 +Contact: Martin K. Petersen <martin.petersen@oracle.com> +Description: + Indicates whether the block layer should verify the + integrity of read requests serviced by devices that + support sending integrity metadata. + + +What: /sys/block/<disk>/integrity/tag_size +Date: June 2008 +Contact: Martin K. Petersen <martin.petersen@oracle.com> +Description: + Number of bytes of integrity tag space available per + 512 bytes of data. + + +What: /sys/block/<disk>/integrity/device_is_integrity_capable +Date: July 2014 +Contact: Martin K. Petersen <martin.petersen@oracle.com> +Description: + Indicates whether a storage device is capable of storing + integrity metadata. Set if the device is T10 PI-capable. + +What: /sys/block/<disk>/integrity/protection_interval_bytes +Date: July 2015 +Contact: Martin K. Petersen <martin.petersen@oracle.com> +Description: + Describes the number of data bytes which are protected + by one integrity tuple. Typically the device's logical + block size. + +What: /sys/block/<disk>/integrity/write_generate +Date: June 2008 +Contact: Martin K. Petersen <martin.petersen@oracle.com> +Description: + Indicates whether the block layer should automatically + generate checksums for write requests bound for + devices that support receiving integrity metadata. + +What: /sys/block/<disk>/alignment_offset +Date: April 2009 +Contact: Martin K. Petersen <martin.petersen@oracle.com> +Description: + Storage devices may report a physical block size that is + bigger than the logical block size (for instance a drive + with 4KB physical sectors exposing 512-byte logical + blocks to the operating system). This parameter + indicates how many bytes the beginning of the device is + offset from the disk's natural alignment. + +What: /sys/block/<disk>/<partition>/alignment_offset +Date: April 2009 +Contact: Martin K. Petersen <martin.petersen@oracle.com> +Description: + Storage devices may report a physical block size that is + bigger than the logical block size (for instance a drive + with 4KB physical sectors exposing 512-byte logical + blocks to the operating system). This parameter + indicates how many bytes the beginning of the partition + is offset from the disk's natural alignment. + +What: /sys/block/<disk>/queue/logical_block_size +Date: May 2009 +Contact: Martin K. Petersen <martin.petersen@oracle.com> +Description: + This is the smallest unit the storage device can + address. It is typically 512 bytes. + +What: /sys/block/<disk>/queue/physical_block_size +Date: May 2009 +Contact: Martin K. Petersen <martin.petersen@oracle.com> +Description: + This is the smallest unit a physical storage device can + write atomically. It is usually the same as the logical + block size but may be bigger. One example is SATA + drives with 4KB sectors that expose a 512-byte logical + block size to the operating system. For stacked block + devices the physical_block_size variable contains the + maximum physical_block_size of the component devices. + +What: /sys/block/<disk>/queue/minimum_io_size +Date: April 2009 +Contact: Martin K. Petersen <martin.petersen@oracle.com> +Description: + Storage devices may report a granularity or preferred + minimum I/O size which is the smallest request the + device can perform without incurring a performance + penalty. For disk drives this is often the physical + block size. For RAID arrays it is often the stripe + chunk size. A properly aligned multiple of + minimum_io_size is the preferred request size for + workloads where a high number of I/O operations is + desired. + +What: /sys/block/<disk>/queue/optimal_io_size +Date: April 2009 +Contact: Martin K. Petersen <martin.petersen@oracle.com> +Description: + Storage devices may report an optimal I/O size, which is + the device's preferred unit for sustained I/O. This is + rarely reported for disk drives. For RAID arrays it is + usually the stripe width or the internal track size. A + properly aligned multiple of optimal_io_size is the + preferred request size for workloads where sustained + throughput is desired. If no optimal I/O size is + reported this file contains 0. + +What: /sys/block/<disk>/queue/nomerges +Date: January 2010 +Contact: +Description: + Standard I/O elevator operations include attempts to + merge contiguous I/Os. For known random I/O loads these + attempts will always fail and result in extra cycles + being spent in the kernel. This allows one to turn off + this behavior on one of two ways: When set to 1, complex + merge checks are disabled, but the simple one-shot merges + with the previous I/O request are enabled. When set to 2, + all merge tries are disabled. The default value is 0 - + which enables all types of merge tries. + +What: /sys/block/<disk>/discard_alignment +Date: May 2011 +Contact: Martin K. Petersen <martin.petersen@oracle.com> +Description: + Devices that support discard functionality may + internally allocate space in units that are bigger than + the exported logical block size. The discard_alignment + parameter indicates how many bytes the beginning of the + device is offset from the internal allocation unit's + natural alignment. + +What: /sys/block/<disk>/<partition>/discard_alignment +Date: May 2011 +Contact: Martin K. Petersen <martin.petersen@oracle.com> +Description: + Devices that support discard functionality may + internally allocate space in units that are bigger than + the exported logical block size. The discard_alignment + parameter indicates how many bytes the beginning of the + partition is offset from the internal allocation unit's + natural alignment. + +What: /sys/block/<disk>/queue/discard_granularity +Date: May 2011 +Contact: Martin K. Petersen <martin.petersen@oracle.com> +Description: + Devices that support discard functionality may + internally allocate space using units that are bigger + than the logical block size. The discard_granularity + parameter indicates the size of the internal allocation + unit in bytes if reported by the device. Otherwise the + discard_granularity will be set to match the device's + physical block size. A discard_granularity of 0 means + that the device does not support discard functionality. + +What: /sys/block/<disk>/queue/discard_max_bytes +Date: May 2011 +Contact: Martin K. Petersen <martin.petersen@oracle.com> +Description: + Devices that support discard functionality may have + internal limits on the number of bytes that can be + trimmed or unmapped in a single operation. Some storage + protocols also have inherent limits on the number of + blocks that can be described in a single command. The + discard_max_bytes parameter is set by the device driver + to the maximum number of bytes that can be discarded in + a single operation. Discard requests issued to the + device must not exceed this limit. A discard_max_bytes + value of 0 means that the device does not support + discard functionality. + +What: /sys/block/<disk>/queue/discard_zeroes_data +Date: May 2011 +Contact: Martin K. Petersen <martin.petersen@oracle.com> +Description: + Will always return 0. Don't rely on any specific behavior + for discards, and don't read this file. + +What: /sys/block/<disk>/queue/write_same_max_bytes +Date: January 2012 +Contact: Martin K. Petersen <martin.petersen@oracle.com> +Description: + Some devices support a write same operation in which a + single data block can be written to a range of several + contiguous blocks on storage. This can be used to wipe + areas on disk or to initialize drives in a RAID + configuration. write_same_max_bytes indicates how many + bytes can be written in a single write same command. If + write_same_max_bytes is 0, write same is not supported + by the device. + +What: /sys/block/<disk>/queue/write_zeroes_max_bytes +Date: November 2016 +Contact: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> +Description: + Devices that support write zeroes operation in which a + single request can be issued to zero out the range of + contiguous blocks on storage without having any payload + in the request. This can be used to optimize writing zeroes + to the devices. write_zeroes_max_bytes indicates how many + bytes can be written in a single write zeroes command. If + write_zeroes_max_bytes is 0, write zeroes is not supported + by the device. + +What: /sys/block/<disk>/queue/zoned +Date: September 2016 +Contact: Damien Le Moal <damien.lemoal@hgst.com> +Description: + zoned indicates if the device is a zoned block device + and the zone model of the device if it is indeed zoned. + The possible values indicated by zoned are "none" for + regular block devices and "host-aware" or "host-managed" + for zoned block devices. The characteristics of + host-aware and host-managed zoned block devices are + described in the ZBC (Zoned Block Commands) and ZAC + (Zoned Device ATA Command Set) standards. These standards + also define the "drive-managed" zone model. However, + since drive-managed zoned block devices do not support + zone commands, they will be treated as regular block + devices and zoned will report "none". + +What: /sys/block/<disk>/queue/chunk_sectors +Date: September 2016 +Contact: Hannes Reinecke <hare@suse.com> +Description: + chunk_sectors has different meaning depending on the type + of the disk. For a RAID device (dm-raid), chunk_sectors + indicates the size in 512B sectors of the RAID volume + stripe segment. For a zoned block device, either + host-aware or host-managed, chunk_sectors indicates the + size of 512B sectors of the zones of the device, with + the eventual exception of the last zone of the device + which may be smaller. diff --git a/Documentation/ABI/testing/sysfs-block-aoe b/Documentation/ABI/testing/sysfs-block-aoe new file mode 100644 index 000000000..b5837765b --- /dev/null +++ b/Documentation/ABI/testing/sysfs-block-aoe @@ -0,0 +1,45 @@ +What: /sys/block/etherd*/mac +Date: Apr, 2005 +KernelVersion: v2.6.12 +Contact: Ed L. Cashin <ed.cashin@acm.org> +Description: + (RO) The ethernet address of the remote Ata over Ethernet (AoE) + device. + +What: /sys/block/etherd*/netif +Date: Apr, 2005 +KernelVersion: v2.6.12 +Contact: Ed L. Cashin <ed.cashin@acm.org> +Description: + (RO) The names of the network interfaces on the localhost (comma + separated) through which we are communicating with the remote + AoE device. + +What: /sys/block/etherd*/state +Date: Apr, 2005 +KernelVersion: v2.6.12 +Contact: Ed L. Cashin <ed.cashin@acm.org> +Description: + (RO) Device status. The state attribute is "up" when the device + is ready for I/O and "down" if detected but unusable. The + "down,closewait" state shows that the device is still open and + cannot come up again until it has been closed. The "up,kickme" + state means that the driver wants to send more commands to the + target but found out there were already the max number of + commands waiting for a response. It will retry again after being + kicked by the periodic timer handler routine. + +What: /sys/block/etherd*/firmware-version +Date: Apr, 2005 +KernelVersion: v2.6.12 +Contact: Ed L. Cashin <ed.cashin@acm.org> +Description: + (RO) Version of the firmware in the target. + +What: /sys/block/etherd*/payload +Date: Dec, 2012 +KernelVersion: v3.10 +Contact: Ed L. Cashin <ed.cashin@acm.org> +Description: + (RO) The amount of user data transferred (in bytes) inside each AoE + command on the network, network headers excluded. diff --git a/Documentation/ABI/testing/sysfs-block-bcache b/Documentation/ABI/testing/sysfs-block-bcache new file mode 100644 index 000000000..9e4bbc5d5 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-block-bcache @@ -0,0 +1,156 @@ +What: /sys/block/<disk>/bcache/unregister +Date: November 2010 +Contact: Kent Overstreet <kent.overstreet@gmail.com> +Description: + A write to this file causes the backing device or cache to be + unregistered. If a backing device had dirty data in the cache, + writeback mode is automatically disabled and all dirty data is + flushed before the device is unregistered. Caches unregister + all associated backing devices before unregistering themselves. + +What: /sys/block/<disk>/bcache/clear_stats +Date: November 2010 +Contact: Kent Overstreet <kent.overstreet@gmail.com> +Description: + Writing to this file resets all the statistics for the device. + +What: /sys/block/<disk>/bcache/cache +Date: November 2010 +Contact: Kent Overstreet <kent.overstreet@gmail.com> +Description: + For a backing device that has cache, a symlink to + the bcache/ dir of that cache. + +What: /sys/block/<disk>/bcache/cache_hits +Date: November 2010 +Contact: Kent Overstreet <kent.overstreet@gmail.com> +Description: + For backing devices: integer number of full cache hits, + counted per bio. A partial cache hit counts as a miss. + +What: /sys/block/<disk>/bcache/cache_misses +Date: November 2010 +Contact: Kent Overstreet <kent.overstreet@gmail.com> +Description: + For backing devices: integer number of cache misses. + +What: /sys/block/<disk>/bcache/cache_hit_ratio +Date: November 2010 +Contact: Kent Overstreet <kent.overstreet@gmail.com> +Description: + For backing devices: cache hits as a percentage. + +What: /sys/block/<disk>/bcache/sequential_cutoff +Date: November 2010 +Contact: Kent Overstreet <kent.overstreet@gmail.com> +Description: + For backing devices: Threshold past which sequential IO will + skip the cache. Read and written as bytes in human readable + units (i.e. echo 10M > sequntial_cutoff). + +What: /sys/block/<disk>/bcache/bypassed +Date: November 2010 +Contact: Kent Overstreet <kent.overstreet@gmail.com> +Description: + Sum of all reads and writes that have bypassed the cache (due + to the sequential cutoff). Expressed as bytes in human + readable units. + +What: /sys/block/<disk>/bcache/writeback +Date: November 2010 +Contact: Kent Overstreet <kent.overstreet@gmail.com> +Description: + For backing devices: When on, writeback caching is enabled and + writes will be buffered in the cache. When off, caching is in + writethrough mode; reads and writes will be added to the + cache but no write buffering will take place. + +What: /sys/block/<disk>/bcache/writeback_running +Date: November 2010 +Contact: Kent Overstreet <kent.overstreet@gmail.com> +Description: + For backing devices: when off, dirty data will not be written + from the cache to the backing device. The cache will still be + used to buffer writes until it is mostly full, at which point + writes transparently revert to writethrough mode. Intended only + for benchmarking/testing. + +What: /sys/block/<disk>/bcache/writeback_delay +Date: November 2010 +Contact: Kent Overstreet <kent.overstreet@gmail.com> +Description: + For backing devices: In writeback mode, when dirty data is + written to the cache and the cache held no dirty data for that + backing device, writeback from cache to backing device starts + after this delay, expressed as an integer number of seconds. + +What: /sys/block/<disk>/bcache/writeback_percent +Date: November 2010 +Contact: Kent Overstreet <kent.overstreet@gmail.com> +Description: + For backing devices: If nonzero, writeback from cache to + backing device only takes place when more than this percentage + of the cache is used, allowing more write coalescing to take + place and reducing total number of writes sent to the backing + device. Integer between 0 and 40. + +What: /sys/block/<disk>/bcache/synchronous +Date: November 2010 +Contact: Kent Overstreet <kent.overstreet@gmail.com> +Description: + For a cache, a boolean that allows synchronous mode to be + switched on and off. In synchronous mode all writes are ordered + such that the cache can reliably recover from unclean shutdown; + if disabled bcache will not generally wait for writes to + complete but if the cache is not shut down cleanly all data + will be discarded from the cache. Should not be turned off with + writeback caching enabled. + +What: /sys/block/<disk>/bcache/discard +Date: November 2010 +Contact: Kent Overstreet <kent.overstreet@gmail.com> +Description: + For a cache, a boolean allowing discard/TRIM to be turned off + or back on if the device supports it. + +What: /sys/block/<disk>/bcache/bucket_size +Date: November 2010 +Contact: Kent Overstreet <kent.overstreet@gmail.com> +Description: + For a cache, bucket size in human readable units, as set at + cache creation time; should match the erase block size of the + SSD for optimal performance. + +What: /sys/block/<disk>/bcache/nbuckets +Date: November 2010 +Contact: Kent Overstreet <kent.overstreet@gmail.com> +Description: + For a cache, the number of usable buckets. + +What: /sys/block/<disk>/bcache/tree_depth +Date: November 2010 +Contact: Kent Overstreet <kent.overstreet@gmail.com> +Description: + For a cache, height of the btree excluding leaf nodes (i.e. a + one node tree will have a depth of 0). + +What: /sys/block/<disk>/bcache/btree_cache_size +Date: November 2010 +Contact: Kent Overstreet <kent.overstreet@gmail.com> +Description: + Number of btree buckets/nodes that are currently cached in + memory; cache dynamically grows and shrinks in response to + memory pressure from the rest of the system. + +What: /sys/block/<disk>/bcache/written +Date: November 2010 +Contact: Kent Overstreet <kent.overstreet@gmail.com> +Description: + For a cache, total amount of data in human readable units + written to the cache, excluding all metadata. + +What: /sys/block/<disk>/bcache/btree_written +Date: November 2010 +Contact: Kent Overstreet <kent.overstreet@gmail.com> +Description: + For a cache, sum of all btree writes in human readable units. diff --git a/Documentation/ABI/testing/sysfs-block-device b/Documentation/ABI/testing/sysfs-block-device new file mode 100644 index 000000000..82ef6eab0 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-block-device @@ -0,0 +1,58 @@ +What: /sys/block/*/device/sw_activity +Date: Jun, 2008 +KernelVersion: v2.6.27 +Contact: linux-ide@vger.kernel.org +Description: + (RW) Used by drivers which support software controlled activity + LEDs. + + It has the following valid values: + + 0 OFF - the LED is not activated on activity + 1 BLINK_ON - the LED blinks on every 10ms when activity is + detected. + 2 BLINK_OFF - the LED is on when idle, and blinks off + every 10ms when activity is detected. + + Note that the user must turn sw_activity OFF it they wish to + control the activity LED via the em_message file. + + +What: /sys/block/*/device/unload_heads +Date: Sep, 2008 +KernelVersion: v2.6.28 +Contact: linux-ide@vger.kernel.org +Description: + (RW) Hard disk shock protection + + Writing an integer value to this file will take the heads of the + respective drive off the platter and block all I/O operations + for the specified number of milliseconds. + + - If the device does not support the unload heads feature, + access is denied with -EOPNOTSUPP. + - The maximal value accepted for a timeout is 30000 + milliseconds. + - A previously set timeout can be cancelled and disk can resume + normal operation immediately by specifying a timeout of 0. + - Some hard drives only comply with an earlier version of the + ATA standard, but support the unload feature nonetheless. + There is no safe way Linux can detect these devices, so this + is not enabled by default. If it is known that your device + does support the unload feature, then you can tell the kernel + to enable it by writing -1. It can be disabled again by + writing -2. + - Values below -2 are rejected with -EINVAL + + For more information, see + Documentation/laptops/disk-shock-protection.txt + + +What: /sys/block/*/device/ncq_prio_enable +Date: Oct, 2016 +KernelVersion: v4.10 +Contact: linux-ide@vger.kernel.org +Description: + (RW) Write to the file to turn on or off the SATA ncq (native + command queueing) support. By default this feature is turned + off. diff --git a/Documentation/ABI/testing/sysfs-block-dm b/Documentation/ABI/testing/sysfs-block-dm new file mode 100644 index 000000000..f9f2339b9 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-block-dm @@ -0,0 +1,47 @@ +What: /sys/block/dm-<num>/dm/name +Date: January 2009 +KernelVersion: 2.6.29 +Contact: dm-devel@redhat.com +Description: Device-mapper device name. + Read-only string containing mapped device name. +Users: util-linux, device-mapper udev rules + +What: /sys/block/dm-<num>/dm/uuid +Date: January 2009 +KernelVersion: 2.6.29 +Contact: dm-devel@redhat.com +Description: Device-mapper device UUID. + Read-only string containing DM-UUID or empty string + if DM-UUID is not set. +Users: util-linux, device-mapper udev rules + +What: /sys/block/dm-<num>/dm/suspended +Date: June 2009 +KernelVersion: 2.6.31 +Contact: dm-devel@redhat.com +Description: Device-mapper device suspend state. + Contains the value 1 while the device is suspended. + Otherwise it contains 0. Read-only attribute. +Users: util-linux, device-mapper udev rules + +What: /sys/block/dm-<num>/dm/rq_based_seq_io_merge_deadline +Date: March 2015 +KernelVersion: 4.1 +Contact: dm-devel@redhat.com +Description: Allow control over how long a request that is a + reasonable merge candidate can be queued on the request + queue. The resolution of this deadline is in + microseconds (ranging from 1 to 100000 usecs). + Setting this attribute to 0 (the default) will disable + request-based DM's merge heuristic and associated extra + accounting. This attribute is not applicable to + bio-based DM devices so it will only ever report 0 for + them. + +What: /sys/block/dm-<num>/dm/use_blk_mq +Date: March 2015 +KernelVersion: 4.1 +Contact: dm-devel@redhat.com +Description: Request-based Device-mapper blk-mq I/O path mode. + Contains the value 1 if the device is using blk-mq. + Otherwise it contains 0. Read-only attribute. diff --git a/Documentation/ABI/testing/sysfs-block-loop b/Documentation/ABI/testing/sysfs-block-loop new file mode 100644 index 000000000..627f4eb87 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-block-loop @@ -0,0 +1,50 @@ +What: /sys/block/loopX/loop/autoclear +Date: Aug, 2010 +KernelVersion: v2.6.37 +Contact: linux-block@vger.kernel.org +Description: + (RO) Shows if the device is in autoclear mode or not ( "1" or + "0"). Autoclear (if set) indicates that the loopback device will + self-distruct after last close. + +What: /sys/block/loopX/loop/backing_file +Date: Aug, 2010 +KernelVersion: v2.6.37 +Contact: linux-block@vger.kernel.org +Description: + (RO) The path of the backing file that the loop device maps its + data blocks to. + +What: /sys/block/loopX/loop/offset +Date: Aug, 2010 +KernelVersion: v2.6.37 +Contact: linux-block@vger.kernel.org +Description: + (RO) Start offset (in bytes). + +What: /sys/block/loopX/loop/sizelimit +Date: Aug, 2010 +KernelVersion: v2.6.37 +Contact: linux-block@vger.kernel.org +Description: + (RO) The size (in bytes) that the block device maps, starting + from the offset. + +What: /sys/block/loopX/loop/partscan +Date: Aug, 2011 +KernelVersion: v3.10 +Contact: linux-block@vger.kernel.org +Description: + (RO) Shows if automatic partition scanning is enabled for the + device or not ("1" or "0"). This can be requested individually + per loop device during its setup by setting LO_FLAGS_PARTSCAN in + in the ioctl request. By default, no partition tables are + scanned. + +What: /sys/block/loopX/loop/dio +Date: Aug, 2015 +KernelVersion: v4.10 +Contact: linux-block@vger.kernel.org +Description: + (RO) Shows if direct IO is being used to access backing file or + not ("1 or "0"). diff --git a/Documentation/ABI/testing/sysfs-block-rssd b/Documentation/ABI/testing/sysfs-block-rssd new file mode 100644 index 000000000..beef30c04 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-block-rssd @@ -0,0 +1,5 @@ +What: /sys/block/rssd*/status +Date: April 2012 +KernelVersion: 3.4 +Contact: Asai Thambi S P <asamymuthupa@micron.com> +Description: This is a read-only file. Indicates the status of the device. diff --git a/Documentation/ABI/testing/sysfs-block-zram b/Documentation/ABI/testing/sysfs-block-zram new file mode 100644 index 000000000..c1513c756 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-block-zram @@ -0,0 +1,100 @@ +What: /sys/block/zram<id>/disksize +Date: August 2010 +Contact: Nitin Gupta <ngupta@vflare.org> +Description: + The disksize file is read-write and specifies the disk size + which represents the limit on the *uncompressed* worth of data + that can be stored in this disk. + Unit: bytes + +What: /sys/block/zram<id>/initstate +Date: August 2010 +Contact: Nitin Gupta <ngupta@vflare.org> +Description: + The initstate file is read-only and shows the initialization + state of the device. + +What: /sys/block/zram<id>/reset +Date: August 2010 +Contact: Nitin Gupta <ngupta@vflare.org> +Description: + The reset file is write-only and allows resetting the + device. The reset operation frees all the memory associated + with this device. + +What: /sys/block/zram<id>/max_comp_streams +Date: February 2014 +Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> +Description: + The max_comp_streams file is read-write and specifies the + number of backend's zcomp_strm compression streams (number of + concurrent compress operations). + +What: /sys/block/zram<id>/comp_algorithm +Date: February 2014 +Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> +Description: + The comp_algorithm file is read-write and lets to show + available and selected compression algorithms, change + compression algorithm selection. + +What: /sys/block/zram<id>/mem_used_max +Date: August 2014 +Contact: Minchan Kim <minchan@kernel.org> +Description: + The mem_used_max file is write-only and is used to reset + the counter of maximum memory zram have consumed to store + compressed data. For resetting the value, you should write + "0". Otherwise, you could see -EINVAL. + Unit: bytes + +What: /sys/block/zram<id>/mem_limit +Date: August 2014 +Contact: Minchan Kim <minchan@kernel.org> +Description: + The mem_limit file is write-only and specifies the maximum + amount of memory ZRAM can use to store the compressed data. + The limit could be changed in run time and "0" means disable + the limit. No limit is the initial state. Unit: bytes + +What: /sys/block/zram<id>/compact +Date: August 2015 +Contact: Minchan Kim <minchan@kernel.org> +Description: + The compact file is write-only and trigger compaction for + allocator zrm uses. The allocator moves some objects so that + it could free fragment space. + +What: /sys/block/zram<id>/io_stat +Date: August 2015 +Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> +Description: + The io_stat file is read-only and accumulates device's I/O + statistics not accounted by block layer. For example, + failed_reads, failed_writes, etc. File format is similar to + block layer statistics file format. + +What: /sys/block/zram<id>/mm_stat +Date: August 2015 +Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> +Description: + The mm_stat file is read-only and represents device's mm + statistics (orig_data_size, compr_data_size, etc.) in a format + similar to block layer statistics file format. + +What: /sys/block/zram<id>/debug_stat +Date: July 2016 +Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> +Description: + The debug_stat file is read-only and represents various + device's debugging info useful for kernel developers. Its + format is not documented intentionally and may change + anytime without any notice. + +What: /sys/block/zram<id>/backing_dev +Date: June 2017 +Contact: Minchan Kim <minchan@kernel.org> +Description: + The backing_dev file is read-write and set up backing + device for zram to write incompressible pages. + For using, user should enable CONFIG_ZRAM_WRITEBACK. |