Documentation/ABI/testing/sysfs-block-zram

   1 What:           /sys/block/zram<id>/disksize
   2 Date:           August 2010
   3 Contact:        Nitin Gupta <ngupta@vflare.org>
   4 Description:
   5                 The disksize file is read-write and specifies the disk size
   6                 which represents the limit on the *uncompressed* worth of data
   7                 that can be stored in this disk.
   8                 Unit: bytes
   9
  10 What:           /sys/block/zram<id>/initstate
  11 Date:           August 2010
  12 Contact:        Nitin Gupta <ngupta@vflare.org>
  13 Description:
  14                 The initstate file is read-only and shows the initialization
  15                 state of the device.
  16
  17 What:           /sys/block/zram<id>/reset
  18 Date:           August 2010
  19 Contact:        Nitin Gupta <ngupta@vflare.org>
  20 Description:
  21                 The reset file is write-only and allows resetting the
  22                 device. The reset operation frees all the memory associated
  23                 with this device.
  24
  25 What:           /sys/block/zram<id>/max_comp_streams
  26 Date:           February 2014
  27 Contact:        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
  28 Description:
  29                 The max_comp_streams file is read-write and specifies the
  30                 number of backend's zcomp_strm compression streams (number of
  31                 concurrent compress operations).
  32
  33 What:           /sys/block/zram<id>/comp_algorithm
  34 Date:           February 2014
  35 Contact:        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
  36 Description:
  37                 The comp_algorithm file is read-write and lets to show
  38                 available and selected compression algorithms, change
  39                 compression algorithm selection.
  40
  41 What:           /sys/block/zram<id>/mem_used_max
  42 Date:           August 2014
  43 Contact:        Minchan Kim <minchan@kernel.org>
  44 Description:
  45                 The mem_used_max file is write-only and is used to reset
  46                 the counter of maximum memory zram have consumed to store
  47                 compressed data. For resetting the value, you should write
  48                 "0". Otherwise, you could see -EINVAL.
  49                 Unit: bytes
  50
  51 What:           /sys/block/zram<id>/mem_limit
  52 Date:           August 2014
  53 Contact:        Minchan Kim <minchan@kernel.org>
  54 Description:
  55                 The mem_limit file is write-only and specifies the maximum
  56                 amount of memory ZRAM can use to store the compressed data.
  57                 The limit could be changed in run time and "0" means disable
  58                 the limit. No limit is the initial state.  Unit: bytes
  59
  60 What:           /sys/block/zram<id>/compact
  61 Date:           August 2015
  62 Contact:        Minchan Kim <minchan@kernel.org>
  63 Description:
  64                 The compact file is write-only and trigger compaction for
  65                 allocator zrm uses. The allocator moves some objects so that
  66                 it could free fragment space.
  67
  68 What:           /sys/block/zram<id>/io_stat
  69 Date:           August 2015
  70 Contact:        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
  71 Description:
  72                 The io_stat file is read-only and accumulates device's I/O
  73                 statistics not accounted by block layer. For example,
  74                 failed_reads, failed_writes, etc. File format is similar to
  75                 block layer statistics file format.
  76
  77 What:           /sys/block/zram<id>/mm_stat
  78 Date:           August 2015
  79 Contact:        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
  80 Description:
  81                 The mm_stat file is read-only and represents device's mm
  82                 statistics (orig_data_size, compr_data_size, etc.) in a format
  83                 similar to block layer statistics file format.
  84
  85 What:           /sys/block/zram<id>/debug_stat
  86 Date:           July 2016
  87 Contact:        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
  88 Description:
  89                 The debug_stat file is read-only and represents various
  90                 device's debugging info useful for kernel developers. Its
  91                 format is not documented intentionally and may change
  92                 anytime without any notice.
  93
  94 What:           /sys/block/zram<id>/backing_dev
  95 Date:           June 2017
  96 Contact:        Minchan Kim <minchan@kernel.org>
  97 Description:
  98                 The backing_dev file is read-write and set up backing
  99                 device for zram to write incompressible pages.
 100                 For using, user should enable CONFIG_ZRAM_WRITEBACK.