diff options
Diffstat (limited to 'Documentation/scheduler/sched-rt-group.txt')
-rw-r--r-- | Documentation/scheduler/sched-rt-group.txt | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/Documentation/scheduler/sched-rt-group.txt b/Documentation/scheduler/sched-rt-group.txt index 1df7f9cdab05..86eabe6c3419 100644 --- a/Documentation/scheduler/sched-rt-group.txt +++ b/Documentation/scheduler/sched-rt-group.txt | |||
@@ -73,7 +73,7 @@ The remaining CPU time will be used for user input and other tasks. Because | |||
73 | realtime tasks have explicitly allocated the CPU time they need to perform | 73 | realtime tasks have explicitly allocated the CPU time they need to perform |
74 | their tasks, buffer underruns in the graphics or audio can be eliminated. | 74 | their tasks, buffer underruns in the graphics or audio can be eliminated. |
75 | 75 | ||
76 | NOTE: the above example is not fully implemented as of yet (2.6.25). We still | 76 | NOTE: the above example is not fully implemented yet. We still |
77 | lack an EDF scheduler to make non-uniform periods usable. | 77 | lack an EDF scheduler to make non-uniform periods usable. |
78 | 78 | ||
79 | 79 | ||
@@ -140,14 +140,15 @@ The other option is: | |||
140 | 140 | ||
141 | .o CONFIG_CGROUP_SCHED (aka "Basis for grouping tasks" = "Control groups") | 141 | .o CONFIG_CGROUP_SCHED (aka "Basis for grouping tasks" = "Control groups") |
142 | 142 | ||
143 | This uses the /cgroup virtual file system and "/cgroup/<cgroup>/cpu.rt_runtime_us" | 143 | This uses the /cgroup virtual file system and |
144 | to control the CPU time reserved for each control group instead. | 144 | "/cgroup/<cgroup>/cpu.rt_runtime_us" to control the CPU time reserved for each |
145 | control group instead. | ||
145 | 146 | ||
146 | For more information on working with control groups, you should read | 147 | For more information on working with control groups, you should read |
147 | Documentation/cgroups/cgroups.txt as well. | 148 | Documentation/cgroups/cgroups.txt as well. |
148 | 149 | ||
149 | Group settings are checked against the following limits in order to keep the configuration | 150 | Group settings are checked against the following limits in order to keep the |
150 | schedulable: | 151 | configuration schedulable: |
151 | 152 | ||
152 | \Sum_{i} runtime_{i} / global_period <= global_runtime / global_period | 153 | \Sum_{i} runtime_{i} / global_period <= global_runtime / global_period |
153 | 154 | ||
@@ -189,7 +190,7 @@ Implementing SCHED_EDF might take a while to complete. Priority Inheritance is | |||
189 | the biggest challenge as the current linux PI infrastructure is geared towards | 190 | the biggest challenge as the current linux PI infrastructure is geared towards |
190 | the limited static priority levels 0-99. With deadline scheduling you need to | 191 | the limited static priority levels 0-99. With deadline scheduling you need to |
191 | do deadline inheritance (since priority is inversely proportional to the | 192 | do deadline inheritance (since priority is inversely proportional to the |
192 | deadline delta (deadline - now). | 193 | deadline delta (deadline - now)). |
193 | 194 | ||
194 | This means the whole PI machinery will have to be reworked - and that is one of | 195 | This means the whole PI machinery will have to be reworked - and that is one of |
195 | the most complex pieces of code we have. | 196 | the most complex pieces of code we have. |