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Commit 99c8b231 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab Committed by Tejun Heo
Browse files

docs: cgroup-v1: convert docs to ReST and rename to *.rst 



Convert the cgroup-v1 files to ReST format, in order to
allow a later addition to the admin-guide.

The conversion is actually:
  - add blank lines and identation in order to identify paragraphs;
  - fix tables markups;
  - add some lists markups;
  - mark literal blocks;
  - adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 38cf3a68

Documentation/admin-guide/hw-vuln/l1tf.rst

+1 −1
Original line number Diff line number Diff line
@@ -241,7 +241,7 @@ Guest mitigation mechanisms 
   For further information about confining guests to a single or to a group

   of cores consult the cpusets documentation:



   https://www.kernel.org/doc/Documentation/cgroup-v1/cpusets.txt

   https://www.kernel.org/doc/Documentation/cgroup-v1/cpusets.rst



.. _interrupt_isolation:

Documentation/admin-guide/kernel-parameters.txt

+2 −2
Original line number Diff line number Diff line
@@ -4078,7 +4078,7 @@ 


	relax_domain_level=

			[KNL, SMP] Set scheduler's default relax_domain_level.

			See Documentation/cgroup-v1/cpusets.txt.

			See Documentation/cgroup-v1/cpusets.rst.



	reserve=	[KNL,BUGS] Force kernel to ignore I/O ports or memory

			Format: <base1>,<size1>[,<base2>,<size2>,...]
@@ -4588,7 +4588,7 @@ 
	swapaccount=[0|1]

			[KNL] Enable accounting of swap in memory resource

			controller if no parameter or 1 is given or disable

			it if 0 is given (See Documentation/cgroup-v1/memory.txt)

			it if 0 is given (See Documentation/cgroup-v1/memory.rst)



	swiotlb=	[ARM,IA-64,PPC,MIPS,X86]

			Format: { <int> | force | noforce }

Documentation/admin-guide/mm/numa_memory_policy.rst

+1 −1
Original line number Diff line number Diff line
@@ -15,7 +15,7 @@ document attempts to describe the concepts and APIs of the 2.6 memory policy 
support.



Memory policies should not be confused with cpusets

(``Documentation/cgroup-v1/cpusets.txt``)

(``Documentation/cgroup-v1/cpusets.rst``)

which is an administrative mechanism for restricting the nodes from which

memory may be allocated by a set of processes. Memory policies are a

programming interface that a NUMA-aware application can take advantage of.  When

Documentation/block/bfq-iosched.txt

+1 −1
Original line number Diff line number Diff line
@@ -539,7 +539,7 @@ As for cgroups-v1 (blkio controller), the exact set of stat files 
created, and kept up-to-date by bfq, depends on whether

CONFIG_DEBUG_BLK_CGROUP is set. If it is set, then bfq creates all

the stat files documented in

Documentation/cgroup-v1/blkio-controller.txt. If, instead,

Documentation/cgroup-v1/blkio-controller.rst. If, instead,

CONFIG_DEBUG_BLK_CGROUP is not set, then bfq creates only the files

blkio.bfq.io_service_bytes

blkio.bfq.io_service_bytes_recursive

Documentation/cgroup-v1/blkio-controller.txt→Documentation/cgroup-v1/blkio-controller.rst

+56 −40
Original line number Diff line number Diff line 
===================

Block IO Controller

===================



Overview

========

cgroup subsys "blkio" implements the block io controller. There seems to be
@@ -22,28 +24,35 @@ Proportional Weight division of bandwidth 
You can do a very simple testing of running two dd threads in two different

cgroups. Here is what you can do.



- Enable Block IO controller

- Enable Block IO controller::



	CONFIG_BLK_CGROUP=y



- Enable group scheduling in CFQ

- Enable group scheduling in CFQ:





	CONFIG_CFQ_GROUP_IOSCHED=y



- Compile and boot into kernel and mount IO controller (blkio); see

  cgroups.txt, Why are cgroups needed?.



  ::



	mount -t tmpfs cgroup_root /sys/fs/cgroup

	mkdir /sys/fs/cgroup/blkio

	mount -t cgroup -o blkio none /sys/fs/cgroup/blkio



- Create two cgroups

- Create two cgroups::



	mkdir -p /sys/fs/cgroup/blkio/test1/ /sys/fs/cgroup/blkio/test2



- Set weights of group test1 and test2

- Set weights of group test1 and test2::



	echo 1000 > /sys/fs/cgroup/blkio/test1/blkio.weight

	echo 500 > /sys/fs/cgroup/blkio/test2/blkio.weight



- Create two same size files (say 512MB each) on same disk (file1, file2) and

  launch two dd threads in different cgroup to read those files.

  launch two dd threads in different cgroup to read those files::



	sync

	echo 3 > /proc/sys/vm/drop_caches
@@ -65,24 +74,27 @@ cgroups. Here is what you can do. 


Throttling/Upper Limit policy

-----------------------------

- Enable Block IO controller

- Enable Block IO controller::



	CONFIG_BLK_CGROUP=y



- Enable throttling in block layer

- Enable throttling in block layer::



	CONFIG_BLK_DEV_THROTTLING=y



- Mount blkio controller (see cgroups.txt, Why are cgroups needed?)

- Mount blkio controller (see cgroups.txt, Why are cgroups needed?)::



        mount -t cgroup -o blkio none /sys/fs/cgroup/blkio



- Specify a bandwidth rate on particular device for root group. The format

  for policy is "<major>:<minor>  <bytes_per_second>".

  for policy is "<major>:<minor>  <bytes_per_second>"::



        echo "8:16  1048576" > /sys/fs/cgroup/blkio/blkio.throttle.read_bps_device



  Above will put a limit of 1MB/second on reads happening for root group

  on device having major/minor number 8:16.



- Run dd to read a file and see if rate is throttled to 1MB/s or not.

- Run dd to read a file and see if rate is throttled to 1MB/s or not::



        # dd iflag=direct if=/mnt/common/zerofile of=/dev/null bs=4K count=1024

        1024+0 records in
@@ -99,7 +111,7 @@ throttling's hierarchy support is enabled iff "sane_behavior" is 
enabled from cgroup side, which currently is a development option and

not publicly available.



If somebody created a hierarchy like as follows.

If somebody created a hierarchy like as follows::



			root

			/  \
@@ -115,7 +127,7 @@ directly generated by tasks in that cgroup. 


Throttling without "sane_behavior" enabled from cgroup side will

practically treat all groups at same level as if it looks like the

following.

following::



				pivot

			     /  /   \  \
@@ -152,23 +164,27 @@ Proportional weight policy files 
	  These rules override the default value of group weight as specified

	  by blkio.weight.



	  Following is the format.

	  Following is the format::



	    # echo dev_maj:dev_minor weight > blkio.weight_device

	  Configure weight=300 on /dev/sdb (8:16) in this cgroup



	  Configure weight=300 on /dev/sdb (8:16) in this cgroup::



	    # echo 8:16 300 > blkio.weight_device

	    # cat blkio.weight_device

	    dev     weight

	    8:16    300



	  Configure weight=500 on /dev/sda (8:0) in this cgroup

	  Configure weight=500 on /dev/sda (8:0) in this cgroup::



	    # echo 8:0 500 > blkio.weight_device

	    # cat blkio.weight_device

	    dev     weight

	    8:0     500

	    8:16    300



	  Remove specific weight for /dev/sda in this cgroup

	  Remove specific weight for /dev/sda in this cgroup::



	    # echo 8:0 0 > blkio.weight_device

	    # cat blkio.weight_device

	    dev     weight
@@ -297,28 +313,28 @@ Throttling/Upper limit policy files 
- blkio.throttle.read_bps_device

	- Specifies upper limit on READ rate from the device. IO rate is

	  specified in bytes per second. Rules are per device. Following is

	  the format.

	  the format::



	    echo "<major>:<minor>  <rate_bytes_per_second>" > /cgrp/blkio.throttle.read_bps_device



- blkio.throttle.write_bps_device

	- Specifies upper limit on WRITE rate to the device. IO rate is

	  specified in bytes per second. Rules are per device. Following is

	  the format.

	  the format::



	    echo "<major>:<minor>  <rate_bytes_per_second>" > /cgrp/blkio.throttle.write_bps_device



- blkio.throttle.read_iops_device

	- Specifies upper limit on READ rate from the device. IO rate is

	  specified in IO per second. Rules are per device. Following is

	  the format.

	  the format::



	   echo "<major>:<minor>  <rate_io_per_second>" > /cgrp/blkio.throttle.read_iops_device



- blkio.throttle.write_iops_device

	- Specifies upper limit on WRITE rate to the device. IO rate is

	  specified in io per second. Rules are per device. Following is

	  the format.

	  the format::



	    echo "<major>:<minor>  <rate_io_per_second>" > /cgrp/blkio.throttle.write_iops_device