On 1/23/20 11:59 AM, Jens Axboe wrote: > On 1/21/20 12:25 PM, muraliraja.muniraju wrote: >> Current loop device implementation has a single kthread worker and >> drains one request at a time to completion. If the underneath device is >> slow then this reduces the concurrency significantly. To help in these >> cases, adding multiple loop workers increases the concurrency. Also to >> retain the old behaviour the default number of loop workers is 1 and can >> be tuned via the ioctl. > > Have you considered using blk-mq for this? Right now loop just does > some basic checks and then queues for a thread. If you bump nr_hw_queues > up (provide a parameter for that) and set BLK_MQ_F_BLOCKING in the > tag flags, then that might be a more viable approach for handling this. Then you could also dump cmd->work, which would shrink loop_cmd by more than 1/3rd. -- Jens Axboe
