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debug_stat sysfs is read-only and represents various debugging data that zram developers may need. This file is not meant to be used by anyone else: its content is not documented and will change any time w/o any notice. Therefore, the output of debug_stat file contains a version string. To avoid any confusion, we will increase the version number every time we modify the output. At the moment this file exports only one value -- the number of re-compressions, IOW, the number of times compression fast path has failed. This stat is temporary any will be useful in case if any per-cpu compression streams regressions will be reported. Link: http://lkml.kernel.org/r/20160513230834.GB26763@bbox Link: http://lkml.kernel.org/r/20160511134553.12655-1-sergey.senozhatsky@gmail.com Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
178 lines
6.2 KiB
Plaintext
178 lines
6.2 KiB
Plaintext
What: /sys/block/zram<id>/disksize
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Date: August 2010
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Contact: Nitin Gupta <ngupta@vflare.org>
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Description:
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The disksize file is read-write and specifies the disk size
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which represents the limit on the *uncompressed* worth of data
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that can be stored in this disk.
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Unit: bytes
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What: /sys/block/zram<id>/initstate
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Date: August 2010
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Contact: Nitin Gupta <ngupta@vflare.org>
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Description:
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The initstate file is read-only and shows the initialization
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state of the device.
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What: /sys/block/zram<id>/reset
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Date: August 2010
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Contact: Nitin Gupta <ngupta@vflare.org>
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Description:
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The reset file is write-only and allows resetting the
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device. The reset operation frees all the memory associated
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with this device.
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What: /sys/block/zram<id>/num_reads
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Date: August 2010
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Contact: Nitin Gupta <ngupta@vflare.org>
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Description:
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The num_reads file is read-only and specifies the number of
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reads (failed or successful) done on this device.
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What: /sys/block/zram<id>/num_writes
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Date: August 2010
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Contact: Nitin Gupta <ngupta@vflare.org>
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Description:
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The num_writes file is read-only and specifies the number of
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writes (failed or successful) done on this device.
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What: /sys/block/zram<id>/invalid_io
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Date: August 2010
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Contact: Nitin Gupta <ngupta@vflare.org>
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Description:
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The invalid_io file is read-only and specifies the number of
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non-page-size-aligned I/O requests issued to this device.
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What: /sys/block/zram<id>/failed_reads
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Date: February 2014
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Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
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Description:
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The failed_reads file is read-only and specifies the number of
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failed reads happened on this device.
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What: /sys/block/zram<id>/failed_writes
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Date: February 2014
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Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
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Description:
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The failed_writes file is read-only and specifies the number of
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failed writes happened on this device.
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What: /sys/block/zram<id>/max_comp_streams
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Date: February 2014
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Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
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Description:
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The max_comp_streams file is read-write and specifies the
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number of backend's zcomp_strm compression streams (number of
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concurrent compress operations).
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What: /sys/block/zram<id>/comp_algorithm
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Date: February 2014
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Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
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Description:
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The comp_algorithm file is read-write and lets to show
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available and selected compression algorithms, change
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compression algorithm selection.
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What: /sys/block/zram<id>/notify_free
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Date: August 2010
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Contact: Nitin Gupta <ngupta@vflare.org>
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Description:
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The notify_free file is read-only. Depending on device usage
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scenario it may account a) the number of pages freed because
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of swap slot free notifications or b) the number of pages freed
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because of REQ_DISCARD requests sent by bio. The former ones
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are sent to a swap block device when a swap slot is freed, which
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implies that this disk is being used as a swap disk. The latter
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ones are sent by filesystem mounted with discard option,
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whenever some data blocks are getting discarded.
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What: /sys/block/zram<id>/zero_pages
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Date: August 2010
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Contact: Nitin Gupta <ngupta@vflare.org>
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Description:
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The zero_pages file is read-only and specifies number of zero
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filled pages written to this disk. No memory is allocated for
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such pages.
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What: /sys/block/zram<id>/orig_data_size
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Date: August 2010
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Contact: Nitin Gupta <ngupta@vflare.org>
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Description:
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The orig_data_size file is read-only and specifies uncompressed
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size of data stored in this disk. This excludes zero-filled
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pages (zero_pages) since no memory is allocated for them.
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Unit: bytes
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What: /sys/block/zram<id>/compr_data_size
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Date: August 2010
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Contact: Nitin Gupta <ngupta@vflare.org>
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Description:
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The compr_data_size file is read-only and specifies compressed
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size of data stored in this disk. So, compression ratio can be
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calculated using orig_data_size and this statistic.
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Unit: bytes
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What: /sys/block/zram<id>/mem_used_total
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Date: August 2010
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Contact: Nitin Gupta <ngupta@vflare.org>
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Description:
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The mem_used_total file is read-only and specifies the amount
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of memory, including allocator fragmentation and metadata
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overhead, allocated for this disk. So, allocator space
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efficiency can be calculated using compr_data_size and this
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statistic.
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Unit: bytes
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What: /sys/block/zram<id>/mem_used_max
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Date: August 2014
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Contact: Minchan Kim <minchan@kernel.org>
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Description:
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The mem_used_max file is read/write and specifies the amount
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of maximum memory zram have consumed to store compressed data.
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For resetting the value, you should write "0". Otherwise,
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you could see -EINVAL.
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Unit: bytes
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What: /sys/block/zram<id>/mem_limit
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Date: August 2014
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Contact: Minchan Kim <minchan@kernel.org>
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Description:
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The mem_limit file is read/write and specifies the maximum
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amount of memory ZRAM can use to store the compressed data. The
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limit could be changed in run time and "0" means disable the
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limit. No limit is the initial state. Unit: bytes
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What: /sys/block/zram<id>/compact
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Date: August 2015
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Contact: Minchan Kim <minchan@kernel.org>
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Description:
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The compact file is write-only and trigger compaction for
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allocator zrm uses. The allocator moves some objects so that
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it could free fragment space.
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What: /sys/block/zram<id>/io_stat
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Date: August 2015
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Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
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Description:
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The io_stat file is read-only and accumulates device's I/O
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statistics not accounted by block layer. For example,
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failed_reads, failed_writes, etc. File format is similar to
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block layer statistics file format.
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What: /sys/block/zram<id>/mm_stat
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Date: August 2015
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Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
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Description:
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The mm_stat file is read-only and represents device's mm
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statistics (orig_data_size, compr_data_size, etc.) in a format
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similar to block layer statistics file format.
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What: /sys/block/zram<id>/debug_stat
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Date: July 2016
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Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
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Description:
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The debug_stat file is read-only and represents various
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device's debugging info useful for kernel developers. Its
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format is not documented intentionally and may change
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anytime without any notice.
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