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kernel/linux-rt-4.4.41/Documentation/ABI/testing/sysfs-block-zram 5.83 KB
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  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>/num_reads
  Date:		August 2010
  Contact:	Nitin Gupta <ngupta@vflare.org>
  Description:
  		The num_reads file is read-only and specifies the number of
  		reads (failed or successful) done on this device.
  
  What:		/sys/block/zram<id>/num_writes
  Date:		August 2010
  Contact:	Nitin Gupta <ngupta@vflare.org>
  Description:
  		The num_writes file is read-only and specifies the number of
  		writes (failed or successful) done on this device.
  
  What:		/sys/block/zram<id>/invalid_io
  Date:		August 2010
  Contact:	Nitin Gupta <ngupta@vflare.org>
  Description:
  		The invalid_io file is read-only and specifies the number of
  		non-page-size-aligned I/O requests issued to this device.
  
  What:		/sys/block/zram<id>/failed_reads
  Date:		February 2014
  Contact:	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
  Description:
  		The failed_reads file is read-only and specifies the number of
  		failed reads happened on this device.
  
  What:		/sys/block/zram<id>/failed_writes
  Date:		February 2014
  Contact:	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
  Description:
  		The failed_writes file is read-only and specifies the number of
  		failed writes happened on 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>/notify_free
  Date:		August 2010
  Contact:	Nitin Gupta <ngupta@vflare.org>
  Description:
  		The notify_free file is read-only. Depending on device usage
  		scenario it may account a) the number of pages freed because
  		of swap slot free notifications or b) the number of pages freed
  		because of REQ_DISCARD requests sent by bio. The former ones
  		are sent to a swap block device when a swap slot is freed, which
  		implies that this disk is being used as a swap disk. The latter
  		ones are sent by filesystem mounted with discard option,
  		whenever some data blocks are getting discarded.
  
  What:		/sys/block/zram<id>/zero_pages
  Date:		August 2010
  Contact:	Nitin Gupta <ngupta@vflare.org>
  Description:
  		The zero_pages file is read-only and specifies number of zero
  		filled pages written to this disk. No memory is allocated for
  		such pages.
  
  What:		/sys/block/zram<id>/orig_data_size
  Date:		August 2010
  Contact:	Nitin Gupta <ngupta@vflare.org>
  Description:
  		The orig_data_size file is read-only and specifies uncompressed
  		size of data stored in this disk. This excludes zero-filled
  		pages (zero_pages) since no memory is allocated for them.
  		Unit: bytes
  
  What:		/sys/block/zram<id>/compr_data_size
  Date:		August 2010
  Contact:	Nitin Gupta <ngupta@vflare.org>
  Description:
  		The compr_data_size file is read-only and specifies compressed
  		size of data stored in this disk. So, compression ratio can be
  		calculated using orig_data_size and this statistic.
  		Unit: bytes
  
  What:		/sys/block/zram<id>/mem_used_total
  Date:		August 2010
  Contact:	Nitin Gupta <ngupta@vflare.org>
  Description:
  		The mem_used_total file is read-only and specifies the amount
  		of memory, including allocator fragmentation and metadata
  		overhead, allocated for this disk. So, allocator space
  		efficiency can be calculated using compr_data_size and this
  		statistic.
  		Unit: bytes
  
  What:		/sys/block/zram<id>/mem_used_max
  Date:		August 2014
  Contact:	Minchan Kim <minchan@kernel.org>
  Description:
  		The mem_used_max file is read/write and specifies the amount
  		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 read/write 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.