Please don't top post, thanks. On 5/22/18 8:36 AM, Vitaly Mayatskih wrote: > I submit with BLK_MQ_REQ_RESERVED | BLK_MQ_REQ_NOWAIT, that never > locked in my testing done on a couple of different configurations. Of > course, it does not say it won't lock elsewhere ;) BLK_MQ_REQ_RESERVED is not something you should use, it's for internal use. If you used NOWAIT, then the issue is likely deadlocking on a lock due to not disabling irqs/bhs. But you can't use submit_bio() from interrupt in any case, it'll even access current process state. That's obviously not valid from an IRQ. > Unfortunately any queuing is chewing up performance, so I'm trying to > find ways around. This way won't work, I'm afraid. -- Jens Axboe
