From 828615950b5876e75587fdd5e9d1185be9cabba7 Mon Sep 17 00:00:00 2001 From: Kir Kolyshkin Date: Thu, 10 Jun 2021 20:07:37 -0700 Subject: 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 Signed-off-by: Kir Kolyshkin Signed-off-by: Jens Axboe --- .../admin-guide/cgroup-v1/blkio-controller.rst | 31 +++++++++++----------- 1 file 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 -- cgit v1.2.3