Commit 77ba015f authored by Sergey Senozhatsky's avatar Sergey Senozhatsky Committed by Linus Torvalds
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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: default avatarSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: default avatarMinchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8811a942

Documentation/blockdev/zram.txt

+34 −14
Original line number Diff line number Diff line
@@ -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

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