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Diffstat (limited to 'Documentation/ABI/testing/sysfs-block-zram')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-block-zram | 177 |
1 files changed, 115 insertions, 62 deletions
diff --git a/Documentation/ABI/testing/sysfs-block-zram b/Documentation/ABI/testing/sysfs-block-zram index ec93fe33baa6..36c57de0a10a 100644 --- a/Documentation/ABI/testing/sysfs-block-zram +++ b/Documentation/ABI/testing/sysfs-block-zram @@ -5,95 +5,148 @@ 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 disksize file is read-only and shows the initialization + 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 disksize file is write-only and allows resetting the - device. The reset operation frees all the memory assocaited + 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> +What: /sys/block/zram<id>/comp_algorithm +Date: February 2014 +Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Description: - The num_reads file is read-only and specifies the number of - reads (failed or successful) done on this device. + 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>/num_writes -Date: August 2010 -Contact: Nitin Gupta <ngupta@vflare.org> +What: /sys/block/zram<id>/mem_used_max +Date: August 2014 +Contact: Minchan Kim <minchan@kernel.org> Description: - The num_writes file is read-only and specifies the number of - writes (failed or successful) done on this device. + The mem_used_max file is write-only and is used to reset + the counter 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>/invalid_io -Date: August 2010 -Contact: Nitin Gupta <ngupta@vflare.org> +What: /sys/block/zram<id>/mem_limit +Date: August 2014 +Contact: Minchan Kim <minchan@kernel.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. + The mem_limit file is write-only 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>/notify_free -Date: August 2010 -Contact: Nitin Gupta <ngupta@vflare.org> +What: /sys/block/zram<id>/compact +Date: August 2015 +Contact: Minchan Kim <minchan@kernel.org> Description: - The notify_free file is read-only and specifies the number of - swap slot free notifications received by this device. These - notifications are send to a swap block device when a swap slot - is freed. This statistic is applicable only when this disk is - being used as a swap disk. + 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>/discard -Date: August 2010 -Contact: Nitin Gupta <ngupta@vflare.org> +What: /sys/block/zram<id>/io_stat +Date: August 2015 +Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Description: - The discard file is read-only and specifies the number of - discard requests received by this device. These requests - provide information to block device regarding blocks which are - no longer used by filesystem. + 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>/zero_pages -Date: August 2010 -Contact: Nitin Gupta <ngupta@vflare.org> +What: /sys/block/zram<id>/mm_stat +Date: August 2015 +Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> 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. + 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. -What: /sys/block/zram<id>/orig_data_size -Date: August 2010 -Contact: Nitin Gupta <ngupta@vflare.org> +What: /sys/block/zram<id>/debug_stat +Date: July 2016 +Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> 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 + The debug_stat file is read-only and represents various + device's debugging info useful for kernel developers. Its + format is not documented intentionally and may change + anytime without any notice. -What: /sys/block/zram<id>/compr_data_size -Date: August 2010 -Contact: Nitin Gupta <ngupta@vflare.org> +What: /sys/block/zram<id>/backing_dev +Date: June 2017 +Contact: Minchan Kim <minchan@kernel.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 + The backing_dev file is read-write and set up backing + device for zram to write incompressible pages. + For using, user should enable CONFIG_ZRAM_WRITEBACK. -What: /sys/block/zram<id>/mem_used_total -Date: August 2010 -Contact: Nitin Gupta <ngupta@vflare.org> +What: /sys/block/zram<id>/idle +Date: November 2018 +Contact: Minchan Kim <minchan@kernel.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 + idle file is write-only and mark zram slot as idle. + If system has mounted debugfs, user can see which slots + are idle via /sys/kernel/debug/zram/zram<id>/block_state + +What: /sys/block/zram<id>/writeback +Date: November 2018 +Contact: Minchan Kim <minchan@kernel.org> +Description: + The writeback file is write-only and trigger idle and/or + huge page writeback to backing device. + +What: /sys/block/zram<id>/bd_stat +Date: November 2018 +Contact: Minchan Kim <minchan@kernel.org> +Description: + The bd_stat file is read-only and represents backing device's + statistics (bd_count, bd_reads, bd_writes) in a format + similar to block layer statistics file format. + +What: /sys/block/zram<id>/writeback_limit_enable +Date: November 2018 +Contact: Minchan Kim <minchan@kernel.org> +Description: + The writeback_limit_enable file is read-write and specifies + eanbe of writeback_limit feature. "1" means eable the feature. + No limit "0" is the initial state. + +What: /sys/block/zram<id>/writeback_limit +Date: November 2018 +Contact: Minchan Kim <minchan@kernel.org> +Description: + The writeback_limit file is read-write and specifies the maximum + amount of writeback ZRAM can do. The limit could be changed + in run time. + +What: /sys/block/zram<id>/recomp_algorithm +Date: November 2022 +Contact: Sergey Senozhatsky <senozhatsky@chromium.org> +Description: + The recomp_algorithm file is read-write and allows to set + or show secondary compression algorithms. + +What: /sys/block/zram<id>/recompress +Date: November 2022 +Contact: Sergey Senozhatsky <senozhatsky@chromium.org> +Description: + The recompress file is write-only and triggers re-compression + with secondary compression algorithms. + +What: /sys/block/zram<id>/algorithm_params +Date: August 2024 +Contact: Sergey Senozhatsky <senozhatsky@chromium.org> +Description: + The algorithm_params file is write-only and is used to setup + compression algorithm parameters. |