summaryrefslogtreecommitdiffstats
path: root/Documentation/ABI/testing/sysfs-class-bdi
blob: b9e8a9368dc6b40a0ee3c97851bbfdd13134ea89 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
What:		/sys/class/bdi/<bdi>/
Date:		January 2008
Contact:	Peter Zijlstra <a.p.zijlstra@chello.nl>
Description:

Provide a place in sysfs for the backing_dev_info object.
This allows us to see and set the various BDI specific variables.

The <bdi> identifier can be either of the following:

MAJOR:MINOR

	Device number for block devices, or value of st_dev on
	non-block filesystems which provide their own BDI, such as NFS
	and FUSE.

default

	The default backing dev, used for non-block device backed
	filesystems which do not provide their own BDI.

Files under /sys/class/bdi/<bdi>/
---------------------------------

read_ahead_kb (read-write)

	Size of the read-ahead window in kilobytes

reclaimable_kb (read-only)

	Reclaimable (dirty or unstable) memory destined for writeback
	to this device

writeback_kb (read-only)

	Memory currently under writeback to this device

dirty_kb (read-only)

	Global threshold for reclaimable + writeback memory

bdi_dirty_kb (read-only)

	Current threshold on this BDI for reclaimable + writeback
	memory

min_ratio (read-write)

	Minimal percentage of global dirty threshold allocated to this
	bdi.  If the value written to this file would make the the sum
	of all min_ratio values exceed 100, then EINVAL is returned.
	The default is zero