sched: documentation: place_entity() comments
Add a few comments to place_entity(). No code changed. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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@ -473,19 +473,26 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
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} else if (sched_feat(APPROX_AVG) && cfs_rq->nr_running)
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} else if (sched_feat(APPROX_AVG) && cfs_rq->nr_running)
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vruntime += sched_vslice(cfs_rq)/2;
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vruntime += sched_vslice(cfs_rq)/2;
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/*
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* The 'current' period is already promised to the current tasks,
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* however the extra weight of the new task will slow them down a
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* little, place the new task so that it fits in the slot that
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* stays open at the end.
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*/
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if (initial && sched_feat(START_DEBIT))
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if (initial && sched_feat(START_DEBIT))
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vruntime += sched_vslice_add(cfs_rq, se);
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vruntime += sched_vslice_add(cfs_rq, se);
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if (!initial) {
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if (!initial) {
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/* sleeps upto a single latency don't count. */
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if (sched_feat(NEW_FAIR_SLEEPERS) && entity_is_task(se) &&
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if (sched_feat(NEW_FAIR_SLEEPERS) && entity_is_task(se) &&
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task_of(se)->policy != SCHED_BATCH)
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task_of(se)->policy != SCHED_BATCH)
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vruntime -= sysctl_sched_latency;
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vruntime -= sysctl_sched_latency;
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vruntime = max_t(s64, vruntime, se->vruntime);
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/* ensure we never gain time by being placed backwards. */
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vruntime = max_vruntime(se->vruntime, vruntime);
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}
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}
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se->vruntime = vruntime;
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se->vruntime = vruntime;
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}
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}
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static void
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static void
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