diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2010-03-16 14:31:44 -0700 |
|---|---|---|
| committer | Clark Williams <williams@redhat.com> | 2012-04-04 09:14:36 -0500 |
| commit | 2a4abb8dc7356fd1f7f5e66834fe6af974d892b5 (patch) | |
| tree | 5a8171d5b13878ec746cd13cd03eec155525d6bd /kernel | |
| parent | 6a8199cb70150d5244d63e7961446b68106e3d9c (diff) | |
sched: Break out from load_balancing on rq_lock contention
Also limit NEW_IDLE pull
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched_fair.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 8a39fa3e3c6c..3747e53ee6a5 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -2899,6 +2899,10 @@ balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, */ if (idle == CPU_NEWLY_IDLE) break; + + if (raw_spin_is_contended(&this_rq->lock) || + raw_spin_is_contended(&busiest->lock)) + break; #endif /* @@ -3039,6 +3043,20 @@ load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest, rem_load_move -= moved_load; if (rem_load_move < 0) break; + +#ifdef CONFIG_PREEMPT + /* + * NEWIDLE balancing is a source of latency, so preemptible + * kernels will stop after the first task is pulled to minimize + * the critical section. + */ + if (idle == CPU_NEWLY_IDLE && this_rq->nr_running) + break; + + if (raw_spin_is_contended(&this_rq->lock) || + raw_spin_is_contended(&busiest->lock)) + break; +#endif } rcu_read_unlock(); |