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Diffstat (limited to 'Documentation/scheduler/sched-deadline.rst')
| -rw-r--r-- | Documentation/scheduler/sched-deadline.rst | 27 |
1 files changed, 13 insertions, 14 deletions
diff --git a/Documentation/scheduler/sched-deadline.rst b/Documentation/scheduler/sched-deadline.rst index 9fe4846079bb..a727827b8dd5 100644 --- a/Documentation/scheduler/sched-deadline.rst +++ b/Documentation/scheduler/sched-deadline.rst @@ -591,12 +591,13 @@ Deadline Task Scheduling The system wide settings are configured under the /proc virtual file system. - For now the -rt knobs are used for -deadline admission control and the - -deadline runtime is accounted against the -rt runtime. We realize that this - isn't entirely desirable; however, it is better to have a small interface for - now, and be able to change it easily later. The ideal situation (see 5.) is to - run -rt tasks from a -deadline server; in which case the -rt bandwidth is a - direct subset of dl_bw. + For now the -rt knobs are used for -deadline admission control and with + CONFIG_RT_GROUP_SCHED the -deadline runtime is accounted against the (root) + -rt runtime. With !CONFIG_RT_GROUP_SCHED the knob only serves for the -dl + admission control. We realize that this isn't entirely desirable; however, it + is better to have a small interface for now, and be able to change it easily + later. The ideal situation (see 5.) is to run -rt tasks from a -deadline + server; in which case the -rt bandwidth is a direct subset of dl_bw. This means that, for a root_domain comprising M CPUs, -deadline tasks can be created while the sum of their bandwidths stays below: @@ -749,21 +750,19 @@ Appendix A. Test suite of the command line options. Please refer to rt-app documentation for more details (`<rt-app-sources>/doc/*.json`). - The second testing application is a modification of schedtool, called - schedtool-dl, which can be used to setup SCHED_DEADLINE parameters for a - certain pid/application. schedtool-dl is available at: - https://github.com/scheduler-tools/schedtool-dl.git. + The second testing application is done using chrt which has support + for SCHED_DEADLINE. The usage is straightforward:: - # schedtool -E -t 10000000:100000000 -e ./my_cpuhog_app + # chrt -d -T 10000000 -D 100000000 0 ./my_cpuhog_app With this, my_cpuhog_app is put to run inside a SCHED_DEADLINE reservation - of 10ms every 100ms (note that parameters are expressed in microseconds). - You can also use schedtool to create a reservation for an already running + of 10ms every 100ms (note that parameters are expressed in nanoseconds). + You can also use chrt to create a reservation for an already running application, given that you know its pid:: - # schedtool -E -t 10000000:100000000 my_app_pid + # chrt -d -T 10000000 -D 100000000 -p 0 my_app_pid Appendix B. Minimal main() ========================== |