Re: [PATCH v3] printk: Add console owner and waiter logic to load balance console writes

[Sergey Senozhatsky]

On (11/02/17 23:15), Steven Rostedt wrote:
> On Thu, 2 Nov 2017 23:16:16 +0100
> Vlastimil Babka <vbabka@xxxxxxx> wrote:
> 
> > > +			if (spin) {
> > > +				/* We spin waiting for the owner to release us */
> > > +				spin_acquire(&console_owner_dep_map, 0, 0, _THIS_IP_);
> > > +				/* Owner will clear console_waiter on hand off */
> > > +				while (!READ_ONCE(console_waiter))  
> > 
> > This should not be negated, right? We should spin while it's true, not
> > false.
> 
> Ug, yes. How did that not crash in my tests.

Ah, right... Good catch, Vlastimil. The V1 didn't work as expected
on my tests.

	-ss