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Documentation / ABI / obsolete / sysfs-block-zram


Based on kernel version 4.10.8. Page generated on 2017-04-01 14:42 EST.

1	What:		/sys/block/zram<id>/num_reads
2	Date:		August 2015
3	Contact:	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
4	Description:
5			The num_reads file is read-only and specifies the number of
6			reads (failed or successful) done on this device.
7			Now accessible via zram<id>/stat node.
8	
9	What:		/sys/block/zram<id>/num_writes
10	Date:		August 2015
11	Contact:	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
12	Description:
13			The num_writes file is read-only and specifies the number of
14			writes (failed or successful) done on this device.
15			Now accessible via zram<id>/stat node.
16	
17	What:		/sys/block/zram<id>/invalid_io
18	Date:		August 2015
19	Contact:	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
20	Description:
21			The invalid_io file is read-only and specifies the number of
22			non-page-size-aligned I/O requests issued to this device.
23			Now accessible via zram<id>/io_stat node.
24	
25	What:		/sys/block/zram<id>/failed_reads
26	Date:		August 2015
27	Contact:	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
28	Description:
29			The failed_reads file is read-only and specifies the number of
30			failed reads happened on this device.
31			Now accessible via zram<id>/io_stat node.
32	
33	What:		/sys/block/zram<id>/failed_writes
34	Date:		August 2015
35	Contact:	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
36	Description:
37			The failed_writes file is read-only and specifies the number of
38			failed writes happened on this device.
39			Now accessible via zram<id>/io_stat node.
40	
41	What:		/sys/block/zram<id>/notify_free
42	Date:		August 2015
43	Contact:	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
44	Description:
45			The notify_free file is read-only. Depending on device usage
46			scenario it may account a) the number of pages freed because
47			of swap slot free notifications or b) the number of pages freed
48			because of REQ_DISCARD requests sent by bio. The former ones
49			are sent to a swap block device when a swap slot is freed, which
50			implies that this disk is being used as a swap disk. The latter
51			ones are sent by filesystem mounted with discard option,
52			whenever some data blocks are getting discarded.
53			Now accessible via zram<id>/io_stat node.
54	
55	What:		/sys/block/zram<id>/zero_pages
56	Date:		August 2015
57	Contact:	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
58	Description:
59			The zero_pages file is read-only and specifies number of zero
60			filled pages written to this disk. No memory is allocated for
61			such pages.
62			Now accessible via zram<id>/mm_stat node.
63	
64	What:		/sys/block/zram<id>/orig_data_size
65	Date:		August 2015
66	Contact:	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
67	Description:
68			The orig_data_size file is read-only and specifies uncompressed
69			size of data stored in this disk. This excludes zero-filled
70			pages (zero_pages) since no memory is allocated for them.
71			Unit: bytes
72			Now accessible via zram<id>/mm_stat node.
73	
74	What:		/sys/block/zram<id>/compr_data_size
75	Date:		August 2015
76	Contact:	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
77	Description:
78			The compr_data_size file is read-only and specifies compressed
79			size of data stored in this disk. So, compression ratio can be
80			calculated using orig_data_size and this statistic.
81			Unit: bytes
82			Now accessible via zram<id>/mm_stat node.
83	
84	What:		/sys/block/zram<id>/mem_used_total
85	Date:		August 2015
86	Contact:	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
87	Description:
88			The mem_used_total file is read-only and specifies the amount
89			of memory, including allocator fragmentation and metadata
90			overhead, allocated for this disk. So, allocator space
91			efficiency can be calculated using compr_data_size and this
92			statistic.
93			Unit: bytes
94			Now accessible via zram<id>/mm_stat node.
95	
96	What:		/sys/block/zram<id>/mem_used_max
97	Date:		August 2015
98	Contact:	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
99	Description:
100			The mem_used_max file is read/write and specifies the amount
101			of maximum memory zram have consumed to store compressed data.
102			For resetting the value, you should write "0". Otherwise,
103			you could see -EINVAL.
104			Unit: bytes
105			Downgraded to write-only node: so it's possible to set new
106			value only; its current value is stored in zram<id>/mm_stat
107			node.
108	
109	What:		/sys/block/zram<id>/mem_limit
110	Date:		August 2015
111	Contact:	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
112	Description:
113			The mem_limit file is read/write and specifies the maximum
114			amount of memory ZRAM can use to store the compressed data.
115			The limit could be changed in run time and "0" means disable
116			the limit.  No limit is the initial state.  Unit: bytes
117			Downgraded to write-only node: so it's possible to set new
118			value only; its current value is stored in zram<id>/mm_stat
119			node.
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