Commit 6e2e312e authored by James Smart's avatar James Smart Committed by Jens Axboe
Browse files

nvmet-fc: remove the IN_ISR deferred scheduling options 



All target lldd's call the cmd receive and op completions in non-isr
thread contexts. As such the IN_ISR options are not necessary.
Remove the functionality and flags, which also removes cpu assignments
to queues.

Signed-off-by: default avatarJames Smart <jsmart2021@gmail.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 03198c4d

drivers/nvme/target/fc.c

+2 −64
Original line number Diff line number Diff line
@@ -86,8 +86,6 @@ struct nvmet_fc_fcp_iod { 
	spinlock_t			flock;



	struct nvmet_req		req;

	struct work_struct		work;

	struct work_struct		done_work;

	struct work_struct		defer_work;



	struct nvmet_fc_tgtport		*tgtport;
@@ -134,7 +132,6 @@ struct nvmet_fc_tgt_queue { 
	u16				sqsize;

	u16				ersp_ratio;

	__le16				sqhd;

	int				cpu;

	atomic_t			connected;

	atomic_t			sqtail;

	atomic_t			zrspcnt;
@@ -232,8 +229,6 @@ static LIST_HEAD(nvmet_fc_portentry_list); 




static void nvmet_fc_handle_ls_rqst_work(struct work_struct *work);

static void nvmet_fc_handle_fcp_rqst_work(struct work_struct *work);

static void nvmet_fc_fcp_rqst_op_done_work(struct work_struct *work);

static void nvmet_fc_fcp_rqst_op_defer_work(struct work_struct *work);

static void nvmet_fc_tgt_a_put(struct nvmet_fc_tgt_assoc *assoc);

static int nvmet_fc_tgt_a_get(struct nvmet_fc_tgt_assoc *assoc);
@@ -438,8 +433,6 @@ nvmet_fc_prep_fcp_iodlist(struct nvmet_fc_tgtport *tgtport, 
	int i;



	for (i = 0; i < queue->sqsize; fod++, i++) {

		INIT_WORK(&fod->work, nvmet_fc_handle_fcp_rqst_work);

		INIT_WORK(&fod->done_work, nvmet_fc_fcp_rqst_op_done_work);

		INIT_WORK(&fod->defer_work, nvmet_fc_fcp_rqst_op_defer_work);

		fod->tgtport = tgtport;

		fod->queue = queue;
@@ -517,9 +510,6 @@ nvmet_fc_queue_fcp_req(struct nvmet_fc_tgtport *tgtport, 
	fcpreq->hwqid = queue->qid ?

			((queue->qid - 1) % tgtport->ops->max_hw_queues) : 0;



	if (tgtport->ops->target_features & NVMET_FCTGTFEAT_CMD_IN_ISR)

		queue_work_on(queue->cpu, queue->work_q, &fod->work);

	else

	nvmet_fc_handle_fcp_rqst(tgtport, fod);

}
@@ -599,30 +589,6 @@ nvmet_fc_free_fcp_iod(struct nvmet_fc_tgt_queue *queue, 
	queue_work(queue->work_q, &fod->defer_work);

}



static int

nvmet_fc_queue_to_cpu(struct nvmet_fc_tgtport *tgtport, int qid)

{

	int cpu, idx, cnt;



	if (tgtport->ops->max_hw_queues == 1)

		return WORK_CPU_UNBOUND;



	/* Simple cpu selection based on qid modulo active cpu count */

	idx = !qid ? 0 : (qid - 1) % num_active_cpus();



	/* find the n'th active cpu */

	for (cpu = 0, cnt = 0; ; ) {

		if (cpu_active(cpu)) {

			if (cnt == idx)

				break;

			cnt++;

		}

		cpu = (cpu + 1) % num_possible_cpus();

	}



	return cpu;

}



static struct nvmet_fc_tgt_queue *

nvmet_fc_alloc_target_queue(struct nvmet_fc_tgt_assoc *assoc,

			u16 qid, u16 sqsize)
@@ -653,7 +619,6 @@ nvmet_fc_alloc_target_queue(struct nvmet_fc_tgt_assoc *assoc, 
	queue->qid = qid;

	queue->sqsize = sqsize;

	queue->assoc = assoc;

	queue->cpu = nvmet_fc_queue_to_cpu(assoc->tgtport, qid);

	INIT_LIST_HEAD(&queue->fod_list);

	INIT_LIST_HEAD(&queue->avail_defer_list);

	INIT_LIST_HEAD(&queue->pending_cmd_list);
@@ -2145,25 +2110,11 @@ nvmet_fc_fod_op_done(struct nvmet_fc_fcp_iod *fod) 
	}

}



static void

nvmet_fc_fcp_rqst_op_done_work(struct work_struct *work)

{

	struct nvmet_fc_fcp_iod *fod =

		container_of(work, struct nvmet_fc_fcp_iod, done_work);



	nvmet_fc_fod_op_done(fod);

}



static void

nvmet_fc_xmt_fcp_op_done(struct nvmefc_tgt_fcp_req *fcpreq)

{

	struct nvmet_fc_fcp_iod *fod = fcpreq->nvmet_fc_private;

	struct nvmet_fc_tgt_queue *queue = fod->queue;



	if (fod->tgtport->ops->target_features & NVMET_FCTGTFEAT_OPDONE_IN_ISR)

		/* context switch so completion is not in ISR context */

		queue_work_on(queue->cpu, queue->work_q, &fod->done_work);

	else

	nvmet_fc_fod_op_done(fod);

}
@@ -2332,19 +2283,6 @@ nvmet_fc_handle_fcp_rqst(struct nvmet_fc_tgtport *tgtport, 
	nvmet_fc_abort_op(tgtport, fod);

}



/*

 * Actual processing routine for received FC-NVME LS Requests from the LLD

 */

static void

nvmet_fc_handle_fcp_rqst_work(struct work_struct *work)

{

	struct nvmet_fc_fcp_iod *fod =

		container_of(work, struct nvmet_fc_fcp_iod, work);

	struct nvmet_fc_tgtport *tgtport = fod->tgtport;



	nvmet_fc_handle_fcp_rqst(tgtport, fod);

}



/**

 * nvmet_fc_rcv_fcp_req - transport entry point called by an LLDD

 *                       upon the reception of a NVME FCP CMD IU.

include/linux/nvme-fc-driver.h

+0 −16
Original line number Diff line number Diff line
@@ -648,22 +648,6 @@ enum { 
		 * sequence in one LLDD operation. Errors during Data

		 * sequence transmit must not allow RSP sequence to be sent.

		 */

	NVMET_FCTGTFEAT_CMD_IN_ISR = (1 << 1),

		/* Bit 2: When 0, the LLDD is calling the cmd rcv handler

		 * in a non-isr context, allowing the transport to finish

		 * op completion in the calling context. When 1, the LLDD

		 * is calling the cmd rcv handler in an ISR context,

		 * requiring the transport to transition to a workqueue

		 * for op completion.

		 */

	NVMET_FCTGTFEAT_OPDONE_IN_ISR = (1 << 2),

		/* Bit 3: When 0, the LLDD is calling the op done handler

		 * in a non-isr context, allowing the transport to finish

		 * op completion in the calling context. When 1, the LLDD

		 * is calling the op done handler in an ISR context,

		 * requiring the transport to transition to a workqueue

		 * for op completion.

		 */

};