Documentation/ABI/obsolete/sysfs-block-zram

   1 What:           /sys/block/zram<id>/num_reads
   2 Date:           August 2015
   3 Contact:        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
   4 Description:
   5                 The num_reads file is read-only and specifies the number of
   6                 reads (failed or successful) done on this device.
   7                 Now accessible via zram<id>/stat node.
   8
   9 What:           /sys/block/zram<id>/num_writes
  10 Date:           August 2015
  11 Contact:        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
  12 Description:
  13                 The num_writes file is read-only and specifies the number of
  14                 writes (failed or successful) done on this device.
  15                 Now accessible via zram<id>/stat node.
  16
  17 What:           /sys/block/zram<id>/invalid_io
  18 Date:           August 2015
  19 Contact:        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
  20 Description:
  21                 The invalid_io file is read-only and specifies the number of
  22                 non-page-size-aligned I/O requests issued to this device.
  23                 Now accessible via zram<id>/io_stat node.
  24
  25 What:           /sys/block/zram<id>/failed_reads
  26 Date:           August 2015
  27 Contact:        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
  28 Description:
  29                 The failed_reads file is read-only and specifies the number of
  30                 failed reads happened on this device.
  31                 Now accessible via zram<id>/io_stat node.
  32
  33 What:           /sys/block/zram<id>/failed_writes
  34 Date:           August 2015
  35 Contact:        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
  36 Description:
  37                 The failed_writes file is read-only and specifies the number of
  38                 failed writes happened on this device.
  39                 Now accessible via zram<id>/io_stat node.
  40
  41 What:           /sys/block/zram<id>/notify_free
  42 Date:           August 2015
  43 Contact:        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
  44 Description:
  45                 The notify_free file is read-only. Depending on device usage
  46                 scenario it may account a) the number of pages freed because
  47                 of swap slot free notifications or b) the number of pages freed
  48                 because of REQ_DISCARD requests sent by bio. The former ones
  49                 are sent to a swap block device when a swap slot is freed, which
  50                 implies that this disk is being used as a swap disk. The latter
  51                 ones are sent by filesystem mounted with discard option,
  52                 whenever some data blocks are getting discarded.
  53                 Now accessible via zram<id>/io_stat node.
  54
  55 What:           /sys/block/zram<id>/zero_pages
  56 Date:           August 2015
  57 Contact:        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
  58 Description:
  59                 The zero_pages file is read-only and specifies number of zero
  60                 filled pages written to this disk. No memory is allocated for
  61                 such pages.
  62                 Now accessible via zram<id>/mm_stat node.
  63
  64 What:           /sys/block/zram<id>/orig_data_size
  65 Date:           August 2015
  66 Contact:        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
  67 Description:
  68                 The orig_data_size file is read-only and specifies uncompressed
  69                 size of data stored in this disk. This excludes zero-filled
  70                 pages (zero_pages) since no memory is allocated for them.
  71                 Unit: bytes
  72                 Now accessible via zram<id>/mm_stat node.
  73
  74 What:           /sys/block/zram<id>/compr_data_size
  75 Date:           August 2015
  76 Contact:        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
  77 Description:
  78                 The compr_data_size file is read-only and specifies compressed
  79                 size of data stored in this disk. So, compression ratio can be
  80                 calculated using orig_data_size and this statistic.
  81                 Unit: bytes
  82                 Now accessible via zram<id>/mm_stat node.
  83
  84 What:           /sys/block/zram<id>/mem_used_total
  85 Date:           August 2015
  86 Contact:        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
  87 Description:
  88                 The mem_used_total file is read-only and specifies the amount
  89                 of memory, including allocator fragmentation and metadata
  90                 overhead, allocated for this disk. So, allocator space
  91                 efficiency can be calculated using compr_data_size and this
  92                 statistic.
  93                 Unit: bytes
  94                 Now accessible via zram<id>/mm_stat node.
  95
  96 What:           /sys/block/zram<id>/mem_used_max
  97 Date:           August 2015
  98 Contact:        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
  99 Description:
 100                 The mem_used_max file is read/write and specifies the amount
 101                 of maximum memory zram have consumed to store compressed data.
 102                 For resetting the value, you should write "0". Otherwise,
 103                 you could see -EINVAL.
 104                 Unit: bytes
 105                 Downgraded to write-only node: so it's possible to set new
 106                 value only; its current value is stored in zram<id>/mm_stat
 107                 node.
 108
 109 What:           /sys/block/zram<id>/mem_limit
 110 Date:           August 2015
 111 Contact:        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
 112 Description:
 113                 The mem_limit file is read/write and specifies the maximum
 114                 amount of memory ZRAM can use to store the compressed data.
 115                 The limit could be changed in run time and "0" means disable
 116                 the limit.  No limit is the initial state.  Unit: bytes
 117                 Downgraded to write-only node: so it's possible to set new
 118                 value only; its current value is stored in zram<id>/mm_stat
 119                 node.