On 25 September 2012 13:30, Viresh Kumar viresh.kumar@linaro.org wrote:
On 25 September 2012 16:52, Peter Zijlstra peterz@infradead.org wrote:
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..
But this is what the initial idea during LPC we had. Any improvements here you can suggest?
The main outcome of the LPC was that we should be able to select another CPU than the local one. Using the same policy than timer, is a 1st step to consolidate interface. A next step should be to update the policy of the function
Vincent
@@ -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?
Maybe yes. Will investigate more on it.
Thanks for your early feedback.
-- viresh