disksize RW show and set the device's disk size
initstate RO shows the initialization state of the device
reset WO trigger device reset
-num_reads RO the number of reads
-failed_reads RO the number of failed reads
-num_write RO the number of writes
-failed_writes RO the number of failed writes
-invalid_io RO the number of non-page-size-aligned I/O requests
+mem_used_max WO reset the `mem_used_max' counter (see later)
+mem_limit WO specifies the maximum amount of memory ZRAM can use
+ to store the compressed data
max_comp_streams RW the number of possible concurrent compress operations
comp_algorithm RW show and change the compression algorithm
-notify_free RO the number of notifications to free pages (either
- slot free notifications or REQ_DISCARD requests)
-zero_pages RO the number of zero filled pages written to this disk
-orig_data_size RO uncompressed size of data stored in this disk
-compr_data_size RO compressed size of data stored in this disk
-mem_used_total RO the amount of memory allocated for this disk
-mem_used_max RW the maximum amount of memory zram have consumed to
- store the data (to reset this counter to the actual
- current value, write 1 to this attribute)
-mem_limit RW the maximum amount of memory ZRAM can use to store
- the compressed data
-pages_compacted RO the number of pages freed during compaction
- (available only via zram<id>/mm_stat node)
compact WO trigger memory compaction
debug_stat RO this file is used for zram debugging purposes
-WARNING
-=======
-per-stat sysfs attributes are considered to be deprecated.
-The basic strategy is:
--- the existing RW nodes will be downgraded to WO nodes (in linux 4.11)
--- deprecated RO sysfs nodes will eventually be removed (in linux 4.11)
-
-The list of deprecated attributes can be found here:
-Documentation/ABI/obsolete/sysfs-block-zram
-
-Basically, every attribute that has its own read accessible sysfs node
-(e.g. num_reads) *AND* is accessible via one of the stat files (zram<id>/stat
-or zram<id>/io_stat or zram<id>/mm_stat) is considered to be deprecated.
User space is advised to use the following files to read the device statistics.
layer and, thus, not available in zram<id>/stat file. It consists of a
single line of text and contains the following stats separated by
whitespace:
- failed_reads
- failed_writes
- invalid_io
- notify_free
+ failed_reads the number of failed reads
+ failed_writes the number of failed writes
+ invalid_io the number of non-page-size-aligned I/O requests
+ notify_free 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.
File /sys/block/zram<id>/mm_stat
The stat file represents device's mm statistics. It consists of a single
line of text and contains the following stats separated by whitespace:
- orig_data_size
- compr_data_size
- mem_used_total
- mem_limit
- mem_used_max
- zero_pages
- num_migrated
+ orig_data_size uncompressed size of data stored in this disk.
+ This excludes same-element-filled pages (same_pages) since
+ no memory is allocated for them.
+ Unit: bytes
+ compr_data_size compressed size of data stored in this disk
+ mem_used_total the amount of memory allocated for this disk. This
+ includes 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
+ mem_limit the maximum amount of memory ZRAM can use to store
+ the compressed data
+ mem_used_max the maximum amount of memory zram have consumed to
+ store the data
+ same_pages the number of same element filled pages written to this disk.
+ No memory is allocated for such pages.
+ pages_compacted the number of pages freed during compaction
9) Deactivate:
swapoff /dev/zram0
projects / linux-2.6-block.git / blobdiff