From 4086f7ab46e12cdd22212fd3efcc79e1e787618a Mon Sep 17 00:00:00 2001 From: Vincent Guittot Date: Tue, 8 Nov 2016 10:53:46 +0100 Subject: [PATCH] UPSTREAM: 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. Change-Id: I33782e35fc4711f5901e8c23d6aa7ec5f2ff7ee5 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: Chris Redpath --- kernel/sched/fair.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index a8f86f214b45..e49408d0f590 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3131,6 +3131,7 @@ 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_sum, r * LOAD_AVG_MAX); removed = 1; + set_tg_cfs_propagate(cfs_rq); } if (atomic_long_read(&cfs_rq->removed_util_avg)) { @@ -3138,6 +3139,7 @@ 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_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, @@ -7347,6 +7349,10 @@ 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); } -- 2.34.1