1 What: /sys/class/bdi/<bdi>/
3 Contact: Peter Zijlstra <a.p.zijlstra@chello.nl>
6 Provide a place in sysfs for the backing_dev_info object.
7 This allows us to see and set the various BDI specific variables.
9 The <bdi> identifier can be either of the following:
13 Device number for block devices, or value of st_dev on
14 non-block filesystems which provide their own BDI, such as NFS
19 The default backing dev, used for non-block device backed
20 filesystems which do not provide their own BDI.
22 Files under /sys/class/bdi/<bdi>/
23 ---------------------------------
25 read_ahead_kb (read-write)
27 Size of the read-ahead window in kilobytes
29 reclaimable_kb (read-only)
31 Reclaimable (dirty or unstable) memory destined for writeback
34 writeback_kb (read-only)
36 Memory currently under writeback to this device
40 Global threshold for reclaimable + writeback memory
42 bdi_dirty_kb (read-only)
44 Current threshold on this BDI for reclaimable + writeback
47 min_ratio (read-write)
49 Minimal percentage of global dirty threshold allocated to this
50 bdi. If the value written to this file would make the the sum
51 of all min_ratio values exceed 100, then EINVAL is returned.
52 If min_ratio would become larger than the current max_ratio,
53 then also EINVAL is returned. The default is zero
55 max_ratio (read-write)
57 Maximal percentage of global dirty threshold allocated to this
58 bdi. If max_ratio would become smaller than the current
59 min_ratio, then EINVAL is returned. The default is 100