From 02927c812e8cd4ebd635e567ccd935d9e87075b8 Mon Sep 17 00:00:00 2001 From: Vincent Guittot Date: Tue, 8 Nov 2016 10:53:46 +0100 Subject: [PATCH 11/92] sched/fair: Propagate asynchrous detach 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 Signed-off-by: Peter Zijlstra (Intel) Acked-by: Dietmar Eggemann Cc: Linus Torvalds Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra Cc: Thomas Gleixner 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 (cherry picked from commit 4e5160766fcc9f41bbd38bac11f92dce993644aa) Signed-off-by: Gaku Inami --- kernel/sched/fair.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 8cf26fd..090a9bb 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3219,6 +3219,7 @@ static inline void cfs_rq_util_change(struct cfs_rq *cfs_rq) sub_positive(&sa->load_avg, r); sub_positive(&sa->load_sum, r * LOAD_AVG_MAX); removed_load = 1; + set_tg_cfs_propagate(cfs_rq); } if (atomic_long_read(&cfs_rq->removed_util_avg)) { @@ -3226,6 +3227,7 @@ static inline void cfs_rq_util_change(struct cfs_rq *cfs_rq) sub_positive(&sa->util_avg, r); sub_positive(&sa->util_sum, r * LOAD_AVG_MAX); removed_util = 1; + set_tg_cfs_propagate(cfs_rq); } 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)) 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); } -- 1.9.1