-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Merge branch 'for-2.6.26' of master.kernel.org:/pub/scm/linux/kernel/…
…git/jwboyer/powerpc-4xx into merge
- Loading branch information
Showing
2,197 changed files
with
82,178 additions
and
35,355 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,46 @@ | ||
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 | ||
setting and retrieving 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 | ||
|
||
min_ratio (read-write) | ||
|
||
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) | ||
|
||
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. |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,24 @@ | ||
DMA attributes | ||
============== | ||
|
||
This document describes the semantics of the DMA attributes that are | ||
defined in linux/dma-attrs.h. | ||
|
||
DMA_ATTR_WRITE_BARRIER | ||
---------------------- | ||
|
||
DMA_ATTR_WRITE_BARRIER is a (write) barrier attribute for DMA. DMA | ||
to a memory region with the DMA_ATTR_WRITE_BARRIER attribute forces | ||
all pending DMA writes to complete, and thus provides a mechanism to | ||
strictly order DMA from a device across all intervening busses and | ||
bridges. This barrier is not specific to a particular type of | ||
interconnect, it applies to the system as a whole, and so its | ||
implementation must account for the idiosyncracies of the system all | ||
the way from the DMA device to memory. | ||
|
||
As an example of a situation where DMA_ATTR_WRITE_BARRIER would be | ||
useful, suppose that a device does a DMA write to indicate that data is | ||
ready and available in memory. The DMA of the "completion indication" | ||
could race with data DMA. Mapping the memory used for completion | ||
indications with DMA_ATTR_WRITE_BARRIER would prevent the race. | ||
|
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.