Commit-ID: 46f69fa33712ad12ccaa723e46ed5929ee93589b Gitweb: http://git.kernel.org/tip/46f69fa33712ad12ccaa723e46ed5929ee93589b Author: Matt Fleming <[email protected]> AuthorDate: Wed, 21 Sep 2016 14:38:12 +0100 Committer: Ingo Molnar <[email protected]> CommitDate: Sat, 14 Jan 2017 11:29:32 +0100
sched/fair: Push rq lock pin/unpin into idle_balance() Future patches will emit warnings if rq_clock() is called before update_rq_clock() inside a rq_pin_lock()/rq_unpin_lock() pair. Since there is only one caller of idle_balance() we can push the unpin/repin there. Signed-off-by: Matt Fleming <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Byungchul Park <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Jan Kara <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Luca Abeni <[email protected]> Cc: Mel Gorman <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Petr Mladek <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Sergey Senozhatsky <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Wanpeng Li <[email protected]> Cc: Yuyang Du <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- kernel/sched/fair.c | 27 +++++++++++++++------------ 1 file changed, 15 insertions(+), 12 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 4904412..faf80e1 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3424,7 +3424,7 @@ static inline unsigned long cfs_rq_load_avg(struct cfs_rq *cfs_rq) return cfs_rq->avg.load_avg; } -static int idle_balance(struct rq *this_rq); +static int idle_balance(struct rq *this_rq, struct rq_flags *rf); #else /* CONFIG_SMP */ @@ -3453,7 +3453,7 @@ attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {} static inline void detach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {} -static inline int idle_balance(struct rq *rq) +static inline int idle_balance(struct rq *rq, struct rq_flags *rf) { return 0; } @@ -6320,15 +6320,8 @@ simple: return p; idle: - /* - * This is OK, because current is on_cpu, which avoids it being picked - * for load-balance and preemption/IRQs are still disabled avoiding - * further scheduler activity on it and we're being very careful to - * re-start the picking loop. - */ - rq_unpin_lock(rq, rf); - new_tasks = idle_balance(rq); - rq_repin_lock(rq, rf); + new_tasks = idle_balance(rq, rf); + /* * Because idle_balance() releases (and re-acquires) rq->lock, it is * possible for any higher priority task to appear. In that case we @@ -8297,7 +8290,7 @@ update_next_balance(struct sched_domain *sd, unsigned long *next_balance) * idle_balance is called by schedule() if this_cpu is about to become * idle. Attempts to pull tasks from other CPUs. */ -static int idle_balance(struct rq *this_rq) +static int idle_balance(struct rq *this_rq, struct rq_flags *rf) { unsigned long next_balance = jiffies + HZ; int this_cpu = this_rq->cpu; @@ -8311,6 +8304,14 @@ static int idle_balance(struct rq *this_rq) */ this_rq->idle_stamp = rq_clock(this_rq); + /* + * This is OK, because current is on_cpu, which avoids it being picked + * for load-balance and preemption/IRQs are still disabled avoiding + * further scheduler activity on it and we're being very careful to + * re-start the picking loop. + */ + rq_unpin_lock(this_rq, rf); + if (this_rq->avg_idle < sysctl_sched_migration_cost || !this_rq->rd->overload) { rcu_read_lock(); @@ -8388,6 +8389,8 @@ out: if (pulled_task) this_rq->idle_stamp = 0; + rq_repin_lock(this_rq, rf); + return pulled_task; }
