On 11/21/18 4:01 AM, Mikhail Skorzhinskii wrote:
Sagi Grimberg <[email protected]> writes: > +static inline void nvme_tcp_queue_request(struct nvme_tcp_request *req) > +{ > + struct nvme_tcp_queue *queue = req->queue; > + > + spin_lock_bh(&queue->lock); > + list_add_tail(&req->entry, &queue->send_list); > + spin_unlock_bh(&queue->lock); > + > + queue_work_on(queue->io_cpu, nvme_tcp_wq, &queue->io_work); > +} May be I missing something, but why bother with bottom half version of locking? There are few places where this lock could be accessed: (1) From ->queue_rq() call; (2) From submitting new AEN request; (3) From receiving new R2T; Which one if these originates from bottom half? Not 100% about queue_rq data path, but (2) and (3) looks perfectly safe for me.
Actually, (3) in former versions was invoked in a soft-irq context which was why this included the bh disable, but I guess it can be removed now.
