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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/ABI/testing/sysfs-class-bdi | |
parent | Initial commit. (diff) | |
download | linux-430c2fc249ea5c0536abd21c23382884005c9093.tar.xz linux-430c2fc249ea5c0536abd21c23382884005c9093.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/ABI/testing/sysfs-class-bdi')
-rw-r--r-- | Documentation/ABI/testing/sysfs-class-bdi | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-bdi b/Documentation/ABI/testing/sysfs-class-bdi new file mode 100644 index 000000000..5402bd74b --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-bdi @@ -0,0 +1,54 @@ +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. + +MAJOR:MINOR-fuseblk + + Value of st_dev on fuseblk filesystems. + +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. + +stable_pages_required (read-only) + + If set, the backing device requires that all pages comprising a write + request must not be changed until writeout is complete. |