Re: [PATCH 3/3] workqueue: Schedule work on non-idle cpu instead of current one

On Tue, 2012-09-25 at 16:06 +0530, Viresh Kumar wrote:

@@ -1066,8 +1076,9 @@ int queue_work(struct workqueue_struct *wq, struct work_struct *work) { int ret;

•   ret = queue_work_on(get_cpu(), wq, work);
  

•   put_cpu();
  

•   preempt_disable();
  

•   ret = queue_work_on(wq_select_cpu(), wq, work);
  

•   preempt_enable();
  

return ret; }

Right, so the problem I see here is that wq_select_cpu() is horridly expensive..

@@ -1102,7 +1113,7 @@ static void delayed_work_timer_fn(unsigned long __data) struct delayed_work *dwork = (struct delayed_work *)__data; struct cpu_workqueue_struct *cwq = get_work_cwq(&dwork->work);

•   __queue_work(smp_processor_id(), cwq->wq, &dwork->work);
  

•   __queue_work(wq_select_cpu(), cwq->wq, &dwork->work);
  

}

Shouldn't timer migration have sorted this one?