Commit-ID: 3c4017c13f91069194fce3160944efec50f15a6e Gitweb: http://git.kernel.org/tip/3c4017c13f91069194fce3160944efec50f15a6e Author: Daniel Lezcano <[email protected]> AuthorDate: Fri, 17 Jan 2014 10:04:03 +0100 Committer: Ingo Molnar <[email protected]> CommitDate: Mon, 10 Feb 2014 16:17:07 +0100
sched: Move rq->idle_stamp up to the core idle_balance() modifies the rq->idle_stamp field, making this information shared across core.c and fair.c. As we know if the cpu is going to idle or not with the previous patch, let's encapsulate the rq->idle_stamp information in core.c by moving it up to the caller. The idle_balance() function returns true in case a balancing occured and the cpu won't be idle, false if no balance happened and the cpu is going idle. Signed-off-by: Daniel Lezcano <[email protected]> Cc: [email protected] Signed-off-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- kernel/sched/core.c | 11 +++++++++-- kernel/sched/fair.c | 14 ++++++-------- kernel/sched/sched.h | 2 +- 3 files changed, 16 insertions(+), 11 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 74dd565..417cf65 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2704,8 +2704,15 @@ need_resched: pre_schedule(rq, prev); - if (unlikely(!rq->nr_running)) - idle_balance(rq); + if (unlikely(!rq->nr_running)) { + /* + * We must set idle_stamp _before_ calling idle_balance(), such + * that we measure the duration of idle_balance() as idle time. + */ + rq->idle_stamp = rq_clock(rq); + if (idle_balance(rq)) + rq->idle_stamp = 0; + } put_prev_task(rq, prev); next = pick_next_task(rq); diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 5ebc681..04fea77 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6531,7 +6531,7 @@ out: * idle_balance is called by schedule() if this_cpu is about to become * idle. Attempts to pull tasks from other CPUs. */ -void idle_balance(struct rq *this_rq) +int idle_balance(struct rq *this_rq) { struct sched_domain *sd; int pulled_task = 0; @@ -6539,10 +6539,8 @@ void idle_balance(struct rq *this_rq) u64 curr_cost = 0; int this_cpu = this_rq->cpu; - this_rq->idle_stamp = rq_clock(this_rq); - if (this_rq->avg_idle < sysctl_sched_migration_cost) - return; + return 0; /* * Drop the rq->lock, but keep IRQ/preempt disabled. @@ -6580,10 +6578,8 @@ void idle_balance(struct rq *this_rq) interval = msecs_to_jiffies(sd->balance_interval); if (time_after(next_balance, sd->last_balance + interval)) next_balance = sd->last_balance + interval; - if (pulled_task) { - this_rq->idle_stamp = 0; + if (pulled_task) break; - } } rcu_read_unlock(); @@ -6594,7 +6590,7 @@ void idle_balance(struct rq *this_rq) * A task could have be enqueued in the meantime */ if (this_rq->nr_running && !pulled_task) - return; + return 1; if (pulled_task || time_after(jiffies, this_rq->next_balance)) { /* @@ -6606,6 +6602,8 @@ void idle_balance(struct rq *this_rq) if (curr_cost > this_rq->max_idle_balance_cost) this_rq->max_idle_balance_cost = curr_cost; + + return pulled_task; } /* diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 82c0e02..bb89991 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1158,7 +1158,7 @@ extern const struct sched_class idle_sched_class; extern void update_group_power(struct sched_domain *sd, int cpu); extern void trigger_load_balance(struct rq *rq); -extern void idle_balance(struct rq *this_rq); +extern int idle_balance(struct rq *this_rq); extern void idle_enter_fair(struct rq *this_rq); extern void idle_exit_fair(struct rq *this_rq); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
