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Diffstat (limited to 'Documentation/ABI/testing/sysfs-block-zram')
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diff --git a/Documentation/ABI/testing/sysfs-block-zram b/Documentation/ABI/testing/sysfs-block-zram new file mode 100644 index 000000000..2e69e83bf --- /dev/null +++ b/Documentation/ABI/testing/sysfs-block-zram @@ -0,0 +1,168 @@ +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. |