Commit e5fc6611 can potentially cause rq->max_idle_balance_cost to not be updated, even when load_balance(NEWLY_IDLE) is attempted and the per-sd max cost value is updated.
In this patch, we update the rq->max_idle_balance_cost regardless of whether or not a task has been enqueued while browsing the domains. Signed-off-by: Jason Low <jason.l...@hp.com> --- kernel/sched/fair.c | 9 +++++---- 1 files changed, 5 insertions(+), 4 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 43232b8..3e3ffb8 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6658,6 +6658,7 @@ static int idle_balance(struct rq *this_rq) int this_cpu = this_rq->cpu; idle_enter_fair(this_rq); + /* * We must set idle_stamp _before_ calling idle_balance(), such that we * measure the duration of idle_balance() as idle time. @@ -6710,9 +6711,12 @@ static int idle_balance(struct rq *this_rq) raw_spin_lock(&this_rq->lock); + if (curr_cost > this_rq->max_idle_balance_cost) + this_rq->max_idle_balance_cost = curr_cost; + /* * While browsing the domains, we released the rq lock. - * A task could have be enqueued in the meantime + * A task could have been enqueued in the meantime. */ if (this_rq->cfs.h_nr_running && !pulled_task) { pulled_task = 1; @@ -6727,9 +6731,6 @@ static int idle_balance(struct rq *this_rq) this_rq->next_balance = next_balance; } - if (curr_cost > this_rq->max_idle_balance_cost) - this_rq->max_idle_balance_cost = curr_cost; - out: /* Is there a task of a high priority class? */ if (this_rq->nr_running != this_rq->cfs.h_nr_running) -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/