| Message ID | 20230927103012.9587-3-chrubis@suse.cz |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | Fix sched-rt sysctl files & update docs | expand |
* 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
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.
- 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(-)