1*cf0ca9feSPeter ZijlstraWhat:		/sys/class/bdi/<bdi>/
2*cf0ca9feSPeter ZijlstraDate:		January 2008
3*cf0ca9feSPeter ZijlstraContact:	Peter Zijlstra <a.p.zijlstra@chello.nl>
4*cf0ca9feSPeter ZijlstraDescription:
5*cf0ca9feSPeter Zijlstra
6*cf0ca9feSPeter ZijlstraProvide a place in sysfs for the backing_dev_info object.
7*cf0ca9feSPeter ZijlstraThis allows us to see and set the various BDI specific variables.
8*cf0ca9feSPeter Zijlstra
9*cf0ca9feSPeter ZijlstraThe <bdi> identifier can be either of the following:
10*cf0ca9feSPeter Zijlstra
11*cf0ca9feSPeter ZijlstraMAJOR:MINOR
12*cf0ca9feSPeter Zijlstra
13*cf0ca9feSPeter Zijlstra	Device number for block devices, or value of st_dev on
14*cf0ca9feSPeter Zijlstra	non-block filesystems which provide their own BDI, such as NFS
15*cf0ca9feSPeter Zijlstra	and FUSE.
16*cf0ca9feSPeter Zijlstra
17*cf0ca9feSPeter Zijlstradefault
18*cf0ca9feSPeter Zijlstra
19*cf0ca9feSPeter Zijlstra	The default backing dev, used for non-block device backed
20*cf0ca9feSPeter Zijlstra	filesystems which do not provide their own BDI.
21*cf0ca9feSPeter Zijlstra
22*cf0ca9feSPeter ZijlstraFiles under /sys/class/bdi/<bdi>/
23*cf0ca9feSPeter Zijlstra---------------------------------
24*cf0ca9feSPeter Zijlstra
25*cf0ca9feSPeter Zijlstraread_ahead_kb (read-write)
26*cf0ca9feSPeter Zijlstra
27*cf0ca9feSPeter Zijlstra	Size of the read-ahead window in kilobytes
28*cf0ca9feSPeter Zijlstra
29*cf0ca9feSPeter Zijlstrareclaimable_kb (read-only)
30*cf0ca9feSPeter Zijlstra
31*cf0ca9feSPeter Zijlstra	Reclaimable (dirty or unstable) memory destined for writeback
32*cf0ca9feSPeter Zijlstra	to this device
33*cf0ca9feSPeter Zijlstra
34*cf0ca9feSPeter Zijlstrawriteback_kb (read-only)
35*cf0ca9feSPeter Zijlstra
36*cf0ca9feSPeter Zijlstra	Memory currently under writeback to this device
37*cf0ca9feSPeter Zijlstra
38*cf0ca9feSPeter Zijlstradirty_kb (read-only)
39*cf0ca9feSPeter Zijlstra
40*cf0ca9feSPeter Zijlstra	Global threshold for reclaimable + writeback memory
41*cf0ca9feSPeter Zijlstra
42*cf0ca9feSPeter Zijlstrabdi_dirty_kb (read-only)
43*cf0ca9feSPeter Zijlstra
44*cf0ca9feSPeter Zijlstra	Current threshold on this BDI for reclaimable + writeback
45*cf0ca9feSPeter Zijlstra	memory
46*cf0ca9feSPeter Zijlstra
47