Hi Sergey,

On 12-07-16, 23:03, Sergey Senozhatsky wrote:
> Thanks, Petr.
> 
> 
> so, I'm looking at this thing now:

Thanks. Though just to mention, I have seen this only once yet :)

> : [   12.874909] sched: RT throttling activated for rt_rq ffffffc0ac13fcd0 (cpu 0)
> : [   12.874909] potential CPU hogs:
> : [   12.874909]  printk (292)
> 
> so it's either cond_resched() does not reshed, keeping printk kthread
> active, which, however, upsets the sched and triggers throttling (umm, what);
> 
> or we, somehow, have `console_may_schedule == 0' in this final console_unlock(),
> so cond_resched() never happens.
> 
> I'm looking at mainline 3.10, tho.

My setup currently looks like this:
- 3.10
- + all printk patches from 3.10 to mainline
- + your patches
- Attaching my printk.c, so you can see the current state.

> Viresh, can you verify if we can do cond_resched() from console_unlock()
> (console_may_schedule != 0) ?

I will try that today.

-- 
viresh