Re: Can you help diagnose a weird failed wake?

[Peter Zijlstra]

On Thu, Nov 19, 2020 at 03:53:42PM +0000, David Howells wrote:

>               timeo = wait_var_event_timeout(&cookie->stage, 
> cookie_stage_changed(cookie, stage), 10*HZ);

>                       cookie->stage = stage;                                  
>                             
>                       changed = true;                                         
>                            
>                       break;                                                  
>                             
>               }                                                               
>                            
>               spin_unlock(&cookie->lock);                                     
>                            
>               if (changed) {                                                  
>                             

smp_mb(); // see comment on wake_up_bit() / wakequeue_active()

>                       wake_up_var(&cookie->stage);                            
>