On Sat, Oct 31, 2020 at 09:01:45AM -0600, Jens Axboe wrote: > On 10/31/20 9:00 AM, Jens Axboe wrote: > > On 10/31/20 4:41 AM, Sebastian Andrzej Siewior wrote: > >> On 2020-10-29 14:07:59 [-0700], Sagi Grimberg wrote: > >>>> in which context? > >>> > >>> Not sure what is the question. > >> > >> The question is in which context do you complete your requests. My guess > >> by now is "usually softirq/NAPI and context in rare error case". > > > > There really aren't any rules for this, and it's perfectly legit to > > complete from process context. Maybe you're a kthread driven driver and > > that's how you handle completions. The block completion path has always > > been hard IRQ safe, but possible to call from anywhere. > > A more recent example is polled IO, which will always complete from > process/task context and very much is fast path. But we never IPI for that anyway, so it is the easy case.