1What: /sys/block/zram<id>/disksize 2Date: August 2010 3Contact: Nitin Gupta <ngupta@vflare.org> 4Description: 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 10What: /sys/block/zram<id>/initstate 11Date: August 2010 12Contact: Nitin Gupta <ngupta@vflare.org> 13Description: 14 The initstate file is read-only and shows the initialization 15 state of the device. 16 17What: /sys/block/zram<id>/reset 18Date: August 2010 19Contact: Nitin Gupta <ngupta@vflare.org> 20Description: 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 25What: /sys/block/zram<id>/num_reads 26Date: August 2010 27Contact: Nitin Gupta <ngupta@vflare.org> 28Description: 29 The num_reads file is read-only and specifies the number of 30 reads (failed or successful) done on this device. 31 32What: /sys/block/zram<id>/num_writes 33Date: August 2010 34Contact: Nitin Gupta <ngupta@vflare.org> 35Description: 36 The num_writes file is read-only and specifies the number of 37 writes (failed or successful) done on this device. 38 39What: /sys/block/zram<id>/invalid_io 40Date: August 2010 41Contact: Nitin Gupta <ngupta@vflare.org> 42Description: 43 The invalid_io file is read-only and specifies the number of 44 non-page-size-aligned I/O requests issued to this device. 45 46What: /sys/block/zram<id>/failed_reads 47Date: February 2014 48Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> 49Description: 50 The failed_reads file is read-only and specifies the number of 51 failed reads happened on this device. 52 53What: /sys/block/zram<id>/failed_writes 54Date: February 2014 55Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> 56Description: 57 The failed_writes file is read-only and specifies the number of 58 failed writes happened on this device. 59 60What: /sys/block/zram<id>/max_comp_streams 61Date: February 2014 62Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> 63Description: 64 The max_comp_streams file is read-write and specifies the 65 number of backend's zcomp_strm compression streams (number of 66 concurrent compress operations). 67 68What: /sys/block/zram<id>/comp_algorithm 69Date: February 2014 70Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> 71Description: 72 The comp_algorithm file is read-write and lets to show 73 available and selected compression algorithms, change 74 compression algorithm selection. 75 76What: /sys/block/zram<id>/notify_free 77Date: August 2010 78Contact: Nitin Gupta <ngupta@vflare.org> 79Description: 80 The notify_free file is read-only. Depending on device usage 81 scenario it may account a) the number of pages freed because 82 of swap slot free notifications or b) the number of pages freed 83 because of REQ_DISCARD requests sent by bio. The former ones 84 are sent to a swap block device when a swap slot is freed, which 85 implies that this disk is being used as a swap disk. The latter 86 ones are sent by filesystem mounted with discard option, 87 whenever some data blocks are getting discarded. 88 89What: /sys/block/zram<id>/zero_pages 90Date: August 2010 91Contact: Nitin Gupta <ngupta@vflare.org> 92Description: 93 The zero_pages file is read-only and specifies number of zero 94 filled pages written to this disk. No memory is allocated for 95 such pages. 96 97What: /sys/block/zram<id>/orig_data_size 98Date: August 2010 99Contact: Nitin Gupta <ngupta@vflare.org> 100Description: 101 The orig_data_size file is read-only and specifies uncompressed 102 size of data stored in this disk. This excludes zero-filled 103 pages (zero_pages) since no memory is allocated for them. 104 Unit: bytes 105 106What: /sys/block/zram<id>/compr_data_size 107Date: August 2010 108Contact: Nitin Gupta <ngupta@vflare.org> 109Description: 110 The compr_data_size file is read-only and specifies compressed 111 size of data stored in this disk. So, compression ratio can be 112 calculated using orig_data_size and this statistic. 113 Unit: bytes 114 115What: /sys/block/zram<id>/mem_used_total 116Date: August 2010 117Contact: Nitin Gupta <ngupta@vflare.org> 118Description: 119 The mem_used_total file is read-only and specifies the amount 120 of memory, including allocator fragmentation and metadata 121 overhead, allocated for this disk. So, allocator space 122 efficiency can be calculated using compr_data_size and this 123 statistic. 124 Unit: bytes 125 126What: /sys/block/zram<id>/mem_used_max 127Date: August 2014 128Contact: Minchan Kim <minchan@kernel.org> 129Description: 130 The mem_used_max file is read/write and specifies the amount 131 of maximum memory zram have consumed to store compressed data. 132 For resetting the value, you should write "0". Otherwise, 133 you could see -EINVAL. 134 Unit: bytes 135 136What: /sys/block/zram<id>/mem_limit 137Date: August 2014 138Contact: Minchan Kim <minchan@kernel.org> 139Description: 140 The mem_limit file is read/write and specifies the maximum 141 amount of memory ZRAM can use to store the compressed data. The 142 limit could be changed in run time and "0" means disable the 143 limit. No limit is the initial state. Unit: bytes 144 145What: /sys/block/zram<id>/compact 146Date: August 2015 147Contact: Minchan Kim <minchan@kernel.org> 148Description: 149 The compact file is write-only and trigger compaction for 150 allocator zrm uses. The allocator moves some objects so that 151 it could free fragment space. 152 153What: /sys/block/zram<id>/io_stat 154Date: August 2015 155Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> 156Description: 157 The io_stat file is read-only and accumulates device's I/O 158 statistics not accounted by block layer. For example, 159 failed_reads, failed_writes, etc. File format is similar to 160 block layer statistics file format. 161 162What: /sys/block/zram<id>/mm_stat 163Date: August 2015 164Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> 165Description: 166 The mm_stat file is read-only and represents device's mm 167 statistics (orig_data_size, compr_data_size, etc.) in a format 168 similar to block layer statistics file format. 169 170What: /sys/block/zram<id>/debug_stat 171Date: July 2016 172Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> 173Description: 174 The debug_stat file is read-only and represents various 175 device's debugging info useful for kernel developers. Its 176 format is not documented intentionally and may change 177 anytime without any notice. 178