What: /sys/block/zram/disksize Date: August 2010 Contact: Nitin Gupta 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/initstate Date: August 2010 Contact: Nitin Gupta Description: The initstate file is read-only and shows the initialization state of the device. What: /sys/block/zram/reset Date: August 2010 Contact: Nitin Gupta 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/num_reads Date: August 2010 Contact: Nitin Gupta 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/num_writes Date: August 2010 Contact: Nitin Gupta 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/invalid_io Date: August 2010 Contact: Nitin Gupta 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/failed_reads Date: February 2014 Contact: Sergey Senozhatsky Description: The failed_reads file is read-only and specifies the number of failed reads happened on this device. What: /sys/block/zram/failed_writes Date: February 2014 Contact: Sergey Senozhatsky Description: The failed_writes file is read-only and specifies the number of failed writes happened on this device. What: /sys/block/zram/max_comp_streams Date: February 2014 Contact: Sergey Senozhatsky 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/comp_algorithm Date: February 2014 Contact: Sergey Senozhatsky 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/notify_free Date: August 2010 Contact: Nitin Gupta 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/zero_pages Date: August 2010 Contact: Nitin Gupta 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/orig_data_size Date: August 2010 Contact: Nitin Gupta 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/compr_data_size Date: August 2010 Contact: Nitin Gupta 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/mem_used_total Date: August 2010 Contact: Nitin Gupta 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/mem_used_max Date: August 2014 Contact: Minchan Kim 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/mem_limit Date: August 2014 Contact: Minchan Kim 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/compact Date: August 2015 Contact: Minchan Kim 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/io_stat Date: August 2015 Contact: Sergey Senozhatsky 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/mm_stat Date: August 2015 Contact: Sergey Senozhatsky 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.