#endif /* CONFIG_NO_HZ_COMMON */
#ifdef CONFIG_NO_HZ_FULL
+static inline bool __need_bw_check(struct rq *rq, struct task_struct *p)
+{
+ if (rq->nr_running != 1)
+ return false;
+
+ if (p->sched_class != &fair_sched_class)
+ return false;
+
+ if (!task_on_rq_queued(p))
+ return false;
+
+ return true;
+}
+
bool sched_can_stop_tick(struct rq *rq)
{
int fifo_nr_running;
if (rq->nr_running > 1)
return false;
+ /*
+ * If there is one task and it has CFS runtime bandwidth constraints
+ * and it's on the cpu now we don't want to stop the tick.
+ * This check prevents clearing the bit if a newly enqueued task here is
+ * dequeued by migrating while the constrained task continues to run.
+ * E.g. going from 2->1 without going through pick_next_task().
+ */
+ if (sched_feat(HZ_BW) && __need_bw_check(rq, rq->curr)) {
+ if (cfs_task_bw_constrained(rq->curr))
+ return false;
+ }
+
return true;
}
#endif /* CONFIG_NO_HZ_FULL */
rq_clock_stop_loop_update(rq);
}
+bool cfs_task_bw_constrained(struct task_struct *p)
+{
+ struct cfs_rq *cfs_rq = task_cfs_rq(p);
+
+ if (!cfs_bandwidth_used())
+ return false;
+
+ if (cfs_rq->runtime_enabled ||
+ tg_cfs_bandwidth(cfs_rq->tg)->hierarchical_quota != RUNTIME_INF)
+ return true;
+
+ return false;
+}
+
+#ifdef CONFIG_NO_HZ_FULL
+/* called from pick_next_task_fair() */
+static void sched_fair_update_stop_tick(struct rq *rq, struct task_struct *p)
+{
+ int cpu = cpu_of(rq);
+
+ if (!sched_feat(HZ_BW) || !cfs_bandwidth_used())
+ return;
+
+ if (!tick_nohz_full_cpu(cpu))
+ return;
+
+ if (rq->nr_running != 1)
+ return;
+
+ /*
+ * We know there is only one task runnable and we've just picked it. The
+ * normal enqueue path will have cleared TICK_DEP_BIT_SCHED if we will
+ * be otherwise able to stop the tick. Just need to check if we are using
+ * bandwidth control.
+ */
+ if (cfs_task_bw_constrained(p))
+ tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED);
+}
+#endif
+
#else /* CONFIG_CFS_BANDWIDTH */
static inline bool cfs_bandwidth_used(void)
static inline void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {}
static inline void update_runtime_enabled(struct rq *rq) {}
static inline void unthrottle_offline_cfs_rqs(struct rq *rq) {}
-
+#ifdef CONFIG_CGROUP_SCHED
+bool cfs_task_bw_constrained(struct task_struct *p)
+{
+ return false;
+}
+#endif
#endif /* CONFIG_CFS_BANDWIDTH */
+#if !defined(CONFIG_CFS_BANDWIDTH) || !defined(CONFIG_NO_HZ_FULL)
+static inline void sched_fair_update_stop_tick(struct rq *rq, struct task_struct *p) {}
+#endif
+
/**************************************************
* CFS operations on tasks:
*/
hrtick_start_fair(rq, p);
update_misfit_status(p, rq);
+ sched_fair_update_stop_tick(rq, p);
return p;
extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b);
extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq);
+extern bool cfs_task_bw_constrained(struct task_struct *p);
extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
struct sched_rt_entity *rt_se, int cpu,
#else /* CONFIG_CGROUP_SCHED */
struct cfs_bandwidth { };
+static inline bool cfs_task_bw_constrained(struct task_struct *p) { return false; }
#endif /* CONFIG_CGROUP_SCHED */