sched/fair: Propagate asynchrous detach (4e516076) · Commits · 戴 / test

A task can be asynchronously detached from cfs_rq when migrating between CPUs. The load of the migrated task is then removed from source cfs_rq during its next update. We use this event to set propagation flag. During the load balance, we take advantage of the update of blocked load to propagate any pending changes. The propagation relies on patch: "sched: Fix hierarchical order in rq->leaf_cfs_rq_list" ... which orders children and parents, to ensure that it's done in one pass. Signed-off-by:

Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by:

Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by:

Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bsegall@google.com Cc: kernellwp@gmail.com Cc: pjt@google.com Cc: yuyang.du@intel.com Link: http://lkml.kernel.org/r/1478598827-32372-6-git-send-email-vincent.guittot@linaro.org Signed-off-by:

Ingo Molnar <mingo@kernel.org>

kernel/sched/fair.c

+6 −0

Original line number	Original line	Diff line number	Diff line
	@@ -3219,6 +3219,7 @@ update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq, bool update_freq)
	sub_positive(&sa->load_avg, r);		sub_positive(&sa->load_avg, r);
	sub_positive(&sa->load_sum, r * LOAD_AVG_MAX);		sub_positive(&sa->load_sum, r * LOAD_AVG_MAX);
	removed_load = 1;		removed_load = 1;
			set_tg_cfs_propagate(cfs_rq);
	}		}

	if (atomic_long_read(&cfs_rq->removed_util_avg)) {		if (atomic_long_read(&cfs_rq->removed_util_avg)) {
	@@ -3226,6 +3227,7 @@ update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq, bool update_freq)
	sub_positive(&sa->util_avg, r);		sub_positive(&sa->util_avg, r);
	sub_positive(&sa->util_sum, r * LOAD_AVG_MAX);		sub_positive(&sa->util_sum, r * LOAD_AVG_MAX);
	removed_util = 1;		removed_util = 1;
			set_tg_cfs_propagate(cfs_rq);
	}		}

	decayed = __update_load_avg(now, cpu_of(rq_of(cfs_rq)), sa,		decayed = __update_load_avg(now, cpu_of(rq_of(cfs_rq)), sa,
	@@ -6872,6 +6874,10 @@ static void update_blocked_averages(int cpu)

	if (update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq, true))		if (update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq, true))
	update_tg_load_avg(cfs_rq, 0);		update_tg_load_avg(cfs_rq, 0);

			/* Propagate pending load changes to the parent */
			if (cfs_rq->tg->se[cpu])
			update_load_avg(cfs_rq->tg->se[cpu], 0);
	}		}
	raw_spin_unlock_irqrestore(&rq->lock, flags);		raw_spin_unlock_irqrestore(&rq->lock, flags);
	}		}

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