zram: describe device attrs in documentation

Briefly describe exported device stat attrs in zram documentation.  We
will eventually get rid of per-stat sysfs nodes and, thus, clean up
Documentation/ABI/testing/sysfs-block-zram file, which is the only source
of information about device sysfs nodes.

Add `num_migrated' description, since there is no independent
`num_migrated' sysfs node (and no corresponding sysfs-block-zram entry),
it will be exported via zram<id>/mm_stat file.

At this point we can provide minimal description, because sysfs-block-zram
still contains detailed information.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Sergey Senozhatsky 2015-04-15 16:16:00 -07:00 committed by Linus Torvalds
parent 8811a9421b
commit 77ba015f9d

View file

@ -98,20 +98,40 @@ size of the disk when not in use so a huge zram is wasteful.
mount /dev/zram1 /tmp
7) Stats:
Per-device statistics are exported as various nodes under
/sys/block/zram<id>/
disksize
num_reads
num_writes
failed_reads
failed_writes
invalid_io
notify_free
zero_pages
orig_data_size
compr_data_size
mem_used_total
mem_used_max
Per-device statistics are exported as various nodes under /sys/block/zram<id>/
A brief description of exported device attritbutes. For more details please
read Documentation/ABI/testing/sysfs-block-zram.
Name access description
---- ------ -----------
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
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 memory zram have consumed to
store compressed data
mem_limit RW the maximum amount of memory ZRAM can use to store
the compressed data
num_migrated RO the number of objects migrated migrated by compaction
File /sys/block/zram<id>/stat
Represents block layer statistics. Read Documentation/block/stat.txt for
details.
8) Deactivate:
swapoff /dev/zram0