PM / x86: Save/restore MISC_ENABLE register

[pandora-kernel.git] / Documentation / ABI / testing / sysfs-class-bdi

diff --git a/Documentation/ABI/testing/sysfs-class-bdi b/Documentation/ABI/testing/sysfs-class-bdi
index c55e811..5f50097 100644 (file)
--- a/Documentation/ABI/testing/sysfs-class-bdi
+++ b/Documentation/ABI/testing/sysfs-class-bdi
@@ -3,8 +3,8 @@ 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.
+Provide a place in sysfs for the backing_dev_info object.  This allows
+setting and retrieving various BDI specific variables.
 
 The <bdi> identifier can be either of the following:
 
@@ -14,6 +14,10 @@ MAJOR:MINOR
        non-block filesystems which provide their own BDI, such as NFS
        and FUSE.
 
+MAJOR:MINOR-fuseblk
+
+       Value of st_dev on fuseblk filesystems.
+
 default
 
        The default backing dev, used for non-block device backed
@@ -26,34 +30,21 @@ 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.
-       If min_ratio would become larger than the current max_ratio,
-       then also EINVAL is returned.  The default is zero
+       Under normal circumstances each device is given a part of the
+       total write-back cache that relates to its current average
+       writeout speed in relation to the other devices.
+
+       The 'min_ratio' parameter allows assigning a minimum
+       percentage of the write-back cache to a particular device.
+       For example, this is useful for providing a minimum QoS.
 
 max_ratio (read-write)
 
-       Maximal percentage of global dirty threshold allocated to this
-       bdi.  If max_ratio would become smaller than the current
-       min_ratio, then EINVAL is returned.  The default is 100
+       Allows limiting a particular device to use not more than the
+       given percentage of the write-back cache.  This is useful in
+       situations where we want to avoid one device taking all or
+       most of the write-back cache.  For example in case of an NFS
+       mount that is prone to get stuck, or a FUSE mount which cannot
+       be trusted to play fair.