diff options
Diffstat (limited to 'kernel/sched/core.c')
| -rw-r--r-- | kernel/sched/core.c | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 62cb6b24ab46..825447720620 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -297,7 +297,18 @@ __read_mostly int scheduler_running; */ int sysctl_sched_rt_runtime = 950000; +/* + * Number of sched_yield calls that result in a thread yielding + * to itself before a sleep is injected in its next sched_yield call + * Setting this to -1 will disable adding sleep in sched_yield + */ +const_debug int sysctl_sched_yield_sleep_threshold = 4; +/* + * Sleep duration in us used when sched_yield_sleep_threshold + * is exceeded. + */ +const_debug unsigned int sysctl_sched_yield_sleep_duration = 50; /* * __task_rq_lock - lock the rq @p resides on. @@ -3035,6 +3046,7 @@ need_resched: if (likely(prev != next)) { rq->nr_switches++; rq->curr = next; + prev->yield_count = 0; ++*switch_count; context_switch(rq, prev, next); /* unlocks the rq */ @@ -3046,8 +3058,10 @@ need_resched: */ cpu = smp_processor_id(); rq = cpu_rq(cpu); - } else + } else { + prev->yield_count++; raw_spin_unlock_irq(&rq->lock); + } post_schedule(rq); @@ -4352,6 +4366,8 @@ SYSCALL_DEFINE0(sched_yield) struct rq *rq = this_rq_lock(); schedstat_inc(rq, yld_count); + if (rq->curr->yield_count == sysctl_sched_yield_sleep_threshold) + schedstat_inc(rq, yield_sleep_count); current->sched_class->yield_task(rq); /* @@ -4363,7 +4379,11 @@ SYSCALL_DEFINE0(sched_yield) do_raw_spin_unlock(&rq->lock); sched_preempt_enable_no_resched(); - schedule(); + if (rq->curr->yield_count == sysctl_sched_yield_sleep_threshold) + usleep_range(sysctl_sched_yield_sleep_duration, + sysctl_sched_yield_sleep_duration + 5); + else + schedule(); return 0; } |