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sched_ext: Documentation: Add ops.dequeue() to task lifecycle
Document ops.dequeue() in the sched_ext task lifecycle now that its
semantics are well-defined.
Also update the pseudo-code to use task_is_runnable() consistently and
clarify the case where ops.dispatch() does not refill the time slice.
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
authored by
Andrea Righi
and committed by
Tejun Heo
a4f61f0a
a3c3fb2f
+16
-10
+16
-10
Documentation/scheduler/sched-ext.rst
+16
-10
Documentation/scheduler/sched-ext.rst
···
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ops.runnable(); /* Task becomes ready to run */
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while (task is runnable) {
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while (task_is_runnable(task)) {
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if (task is not in a DSQ && task->scx.slice == 0) {
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ops.enqueue(); /* Task can be added to a DSQ */
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/* Any usable CPU becomes available */
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ops.dispatch(); /* Task is moved to a local DSQ */
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ops.dequeue(); /* Exiting BPF scheduler */
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/* Task property change (i.e., affinity, nice, etc.)? */
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if (sched_change(task)) {
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ops.dequeue(); /* Exiting BPF scheduler custody */
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continue;
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}
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}
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/* Any usable CPU becomes available */
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ops.dispatch(); /* Task is moved to a local DSQ */
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ops.dequeue(); /* Exiting BPF scheduler custody */
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ops.running(); /* Task starts running on its assigned CPU */
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while task_is_runnable(p) {
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while (task->scx.slice > 0 && task_is_runnable(p))
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ops.tick(); /* Called every 1/HZ seconds */
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while (task_is_runnable(task) && task->scx.slice > 0) {
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ops.tick(); /* Called every 1/HZ seconds */
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ops.dispatch(); /* task->scx.slice can be refilled */
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if (task->scx.slice == 0)
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ops.dispatch(); /* task->scx.slice can be refilled */
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}
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ops.stopping(); /* Task stops running (time slice expires or wait) */