On 11/09, Thomas Gleixner wrote: > > > - watchdog_park_threads() and it does not look nice. The code is actually > > correct, get_online_cpus() ensures that kthread_park() can't race with > > itself (note that kthread_park() can't handle this race correctly), but > > imo it should not use kthread_park() directly. > > Should we provide an interface through the smpboot thread infrastructure for > this?
IMHO yes, I'll write another email. > I can see why that gpu driver wants to use the park mechanism and I guess > there are other legitimate use cases as well. I prefer to implement a > park/unpark variant which is safe to use on arbitrary kthreads Yes, agreed. Again, I'll write another email. Perhaps we should even keep park/unpark exported and change them to avoid the races with exit/itself, I dunno. My real point was, imo the KTHREAD_IS_PER_CPU/__kthread_bind(kthread->cpu) logic in kthread_unpark() should be private to smpboot.c/cpu.c. I'll send another patch tomorrow. kthread_create_worker_on_cpu() ab-uses this logic too for no reason, but this is trivial. > Reviewed-by: Thomas Gleixner <t...@linutronix.de> Thanks! Probably I should re-send these 2 short series to Ingo with your acks applied. Oleg.
