- Describe explicitly that sched_rt_runtime_us is allocated from
  sched_rt_period_us and hence always less or equal to that value.

- The limit for sched_rt_runtime_us is not INT_MAX - 1 but rather it's
  limited by the value of sched_rt_period_us. If sched_rt_period_us is
  INT_MAX then sched_rt_runtime_us can be set to INT_MAX as well.

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
---
 Documentation/scheduler/sched-rt-group.rst | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/Documentation/scheduler/sched-rt-group.rst b/Documentation/scheduler/sched-rt-group.rst
index 655a096ec8fb..033661a5838f 100644
--- a/Documentation/scheduler/sched-rt-group.rst
+++ b/Documentation/scheduler/sched-rt-group.rst
@@ -87,18 +87,20 @@ lack an EDF scheduler to make non-uniform periods usable.
 The system wide settings are configured under the /proc virtual file system:
 
 /proc/sys/kernel/sched_rt_period_us:
-  The scheduling period that is equivalent to 100% CPU bandwidth
+  The scheduling period that is equivalent to 100% CPU bandwidth.
 
 /proc/sys/kernel/sched_rt_runtime_us:
-  A global limit on how much time realtime scheduling may use.  Even without
-  CONFIG_RT_GROUP_SCHED enabled, this will limit time reserved to realtime
-  processes. With CONFIG_RT_GROUP_SCHED it signifies the total bandwidth
-  available to all realtime groups.
+  A global limit on how much time realtime scheduling may use. This is always
+  less or equal than the period_us as it denotes the time allocated from the
+  period_us for the realtime tasks. Even without CONFIG_RT_GROUP_SCHED enabled,
+  this will limit time reserved to realtime processes. With
+  CONFIG_RT_GROUP_SCHED it signifies the total bandwidth available to all
+  realtime groups.
 
   * Time is specified in us because the interface is s32. This gives an
     operating range from 1us to about 35 minutes.
   * sched_rt_period_us takes values from 1 to INT_MAX.
-  * sched_rt_runtime_us takes values from -1 to (INT_MAX - 1).
+  * sched_rt_runtime_us takes values from -1 to sched_rt_period_us.
   * A run time of -1 specifies runtime == period, ie. no limit.
 
 
-- 
2.41.0

* Cyril Hrubis <chrubis@suse.cz> wrote:

> - Describe explicitly that sched_rt_runtime_us is allocated from
>   sched_rt_period_us and hence always less or equal to that value.

Just some spelling nits:

> - The limit for sched_rt_runtime_us is not INT_MAX - 1 but rather it's
>   limited by the value of sched_rt_period_us. If sched_rt_period_us is
>   INT_MAX then sched_rt_runtime_us can be set to INT_MAX as well.

s/is not INT_MAX - 1 but rather it's
 /is not INT_MAX-1, but rather it's

>  /proc/sys/kernel/sched_rt_runtime_us:
> -  A global limit on how much time realtime scheduling may use.  Even without
> -  CONFIG_RT_GROUP_SCHED enabled, this will limit time reserved to realtime
> -  processes. With CONFIG_RT_GROUP_SCHED it signifies the total bandwidth
> -  available to all realtime groups.
> +  A global limit on how much time realtime scheduling may use. This is always

s/realtime
 /real-time

> +  less or equal than the period_us as it denotes the time allocated from the

s/than the period_us as it denotes
 /than the period_us, as it denotes

> +  period_us for the realtime tasks. Even without CONFIG_RT_GROUP_SCHED enabled,
> +  this will limit time reserved to realtime processes. With

s/realtime
 /real-time

> +  CONFIG_RT_GROUP_SCHED it signifies the total bandwidth available to all

s/CONFIG_RT_GROUP_SCHED
 /CONFIG_RT_GROUP_SCHED=y

> +  realtime groups.

s/realtime
 /real-time

Thanks,

	Ingo