X-Git-Url: http://git.monstr.eu/?a=blobdiff_plain;f=Documentation%2Fadmin-guide%2Fcgroup-v2.rst;h=5c7377b5bd3e37b086db5d245a7e9027fffad17b;hb=6bbf59145c4b29a384b0a66d63ddfbf55eeb91c4;hp=b1e81aa8598a5b98b5fd76859c103e66e756d1a5;hpb=ccd1950c2f7e38ae45aeefb99a08b39407cd6c63;p=linux-2.6-microblaze.git

diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
index b1e81aa8598a..5c7377b5bd3e 100644
--- a/Documentation/admin-guide/cgroup-v2.rst
+++ b/Documentation/admin-guide/cgroup-v2.rst
@@ -56,6 +56,7 @@ v1 is available under :ref:`Documentation/admin-guide/cgroup-v1/index.rst <cgrou
        5-3-3. IO Latency
          5-3-3-1. How IO Latency Throttling Works
          5-3-3-2. IO Latency Interface Files
+       5-3-4. IO Priority
      5-4. PID
        5-4-1. PID Interface Files
      5-5. Cpuset
@@ -952,6 +953,21 @@ All cgroup core files are prefixed with "cgroup."
 	it's possible to delete a frozen (and empty) cgroup, as well as
 	create new sub-cgroups.
 
+  cgroup.kill
+	A write-only single value file which exists in non-root cgroups.
+	The only allowed value is "1".
+
+	Writing "1" to the file causes the cgroup and all descendant cgroups to
+	be killed. This means that all processes located in the affected cgroup
+	tree will be killed via SIGKILL.
+
+	Killing a cgroup tree will deal with concurrent forks appropriately and
+	is protected against migrations.
+
+	In a threaded cgroup, writing this file fails with EOPNOTSUPP as
+	killing cgroups is a process directed operation, i.e. it affects
+	the whole thread-group.
+
 Controllers
 ===========
 
@@ -1866,6 +1882,60 @@ IO Latency Interface Files
 		duration of time between evaluation events.  Windows only elapse
 		with IO activity.  Idle periods extend the most recent window.
 
+IO Priority
+~~~~~~~~~~~
+
+A single attribute controls the behavior of the I/O priority cgroup policy,
+namely the blkio.prio.class attribute. The following values are accepted for
+that attribute:
+
+  no-change
+	Do not modify the I/O priority class.
+
+  none-to-rt
+	For requests that do not have an I/O priority class (NONE),
+	change the I/O priority class into RT. Do not modify
+	the I/O priority class of other requests.
+
+  restrict-to-be
+	For requests that do not have an I/O priority class or that have I/O
+	priority class RT, change it into BE. Do not modify the I/O priority
+	class of requests that have priority class IDLE.
+
+  idle
+	Change the I/O priority class of all requests into IDLE, the lowest
+	I/O priority class.
+
+The following numerical values are associated with the I/O priority policies:
+
++-------------+---+
+| no-change   | 0 |
++-------------+---+
+| none-to-rt  | 1 |
++-------------+---+
+| rt-to-be    | 2 |
++-------------+---+
+| all-to-idle | 3 |
++-------------+---+
+
+The numerical value that corresponds to each I/O priority class is as follows:
+
++-------------------------------+---+
+| IOPRIO_CLASS_NONE             | 0 |
++-------------------------------+---+
+| IOPRIO_CLASS_RT (real-time)   | 1 |
++-------------------------------+---+
+| IOPRIO_CLASS_BE (best effort) | 2 |
++-------------------------------+---+
+| IOPRIO_CLASS_IDLE             | 3 |
++-------------------------------+---+
+
+The algorithm to set the I/O priority class for a request is as follows:
+
+- Translate the I/O priority class policy into a number.
+- Change the request I/O priority class into the maximum of the I/O priority
+  class policy number and the numerical I/O priority class.
+
 PID
 ---