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| author | Kir Kolyshkin <kolyshkin@gmail.com> | 2021-06-10 20:07:37 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-06-16 11:32:03 -0600 |
| commit | 828615950b5876e75587fdd5e9d1185be9cabba7 (patch) | |
| tree | 731b09bab247f7a1f968d96744e15a824aa67453 | |
| parent | 37fe403898b2fa5fc9d3616fcda2ee6629318aab (diff) | |
| download | lwn-828615950b5876e75587fdd5e9d1185be9cabba7.tar.gz lwn-828615950b5876e75587fdd5e9d1185be9cabba7.zip | |
docs/cgroup-v1/blkio: update for 5.x kernels
Commit bf382fb0bcef4 ("block: remove legacy IO schedulers", Oct 12 2018)
removes the CFQ scheduler, together with blkio.weight and
blkio.weight_device described in cgroup v1 documentation. Users are
supposed to use the BFQ scheduler, which cgroup file for setting weight
is blkio.bfq.weight, but there is no way to set per-device weight.
Later, commit 795fe54c2a8 per-device weights for BFQ, meaning that
blkio.bfq.weight and blkio.bfq.weight_device can be used in a way
similar to the old CFQ cgroup interface.
Yet, the cgroup v1 docs were never updated. Fix this:
- use the new file names;
- fix the range for weight (used to be 10..1000, now 1..1000);
- link to BFQ scheduler docs.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | Documentation/admin-guide/cgroup-v1/blkio-controller.rst | 31 |
1 files changed, 16 insertions, 15 deletions
diff --git a/Documentation/admin-guide/cgroup-v1/blkio-controller.rst b/Documentation/admin-guide/cgroup-v1/blkio-controller.rst index 8101dcba381d..16253eda192e 100644 --- a/Documentation/admin-guide/cgroup-v1/blkio-controller.rst +++ b/Documentation/admin-guide/cgroup-v1/blkio-controller.rst @@ -97,40 +97,41 @@ Details of cgroup files Proportional weight policy files -------------------------------- - blkio.weight + blkio.bfq.weight Specifies per cgroup weight. This is default weight of the group - on all the devices until and unless overridden by per device rule. - (See blkio.weight_device). - Currently allowed range of weights is from 10 to 1000. + on all the devices until and unless overridden by per device rule + (see `blkio.bfq.weight_device` below). - blkio.weight_device - One can specify per cgroup per device rules using this interface. - These rules override the default value of group weight as specified - by blkio.weight. + Currently allowed range of weights is from 1 to 1000. For more details, + see Documentation/block/bfq-iosched.rst. + + blkio.bfq.weight_device + Specifes per cgroup per device weights, overriding the default group + weight. For more details, see Documentation/block/bfq-iosched.rst. Following is the format:: - # echo dev_maj:dev_minor weight > blkio.weight_device + # echo dev_maj:dev_minor weight > blkio.bfq.weight_device Configure weight=300 on /dev/sdb (8:16) in this cgroup:: - # echo 8:16 300 > blkio.weight_device - # cat blkio.weight_device + # echo 8:16 300 > blkio.bfq.weight_device + # cat blkio.bfq.weight_device dev weight 8:16 300 Configure weight=500 on /dev/sda (8:0) in this cgroup:: - # echo 8:0 500 > blkio.weight_device - # cat blkio.weight_device + # echo 8:0 500 > blkio.bfq.weight_device + # cat blkio.bfq.weight_device dev weight 8:0 500 8:16 300 Remove specific weight for /dev/sda in this cgroup:: - # echo 8:0 0 > blkio.weight_device - # cat blkio.weight_device + # echo 8:0 0 > blkio.bfq.weight_device + # cat blkio.bfq.weight_device dev weight 8:16 300 |