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Commit cee687b6 authored by Bart Van Assche's avatar Bart Van Assche Committed by Doug Ledford
Browse files

IB/srp: Cache global rkey 



This is a micro-optimization for the hot path.

Signed-off-by: default avatarBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
parent 9566b054

drivers/infiniband/ulp/srp/ib_srp.c

+14 −13
Original line number Diff line number Diff line
@@ -1292,7 +1292,6 @@ static int srp_map_finish_fmr(struct srp_map_state *state, 
{

	struct srp_target_port *target = ch->target;

	struct srp_device *dev = target->srp_host->srp_dev;

	struct ib_pd *pd = target->pd;

	struct ib_pool_fmr *fmr;

	u64 io_addr = 0;
@@ -1308,9 +1307,9 @@ static int srp_map_finish_fmr(struct srp_map_state *state, 
	if (state->npages == 0)

		return 0;



	if (state->npages == 1 && (pd->flags & IB_PD_UNSAFE_GLOBAL_RKEY)) {

	if (state->npages == 1 && target->global_rkey) {

		srp_map_desc(state, state->base_dma_addr, state->dma_len,

			     pd->unsafe_global_rkey);

			     target->global_rkey);

		goto reset_state;

	}
@@ -1350,7 +1349,6 @@ static int srp_map_finish_fr(struct srp_map_state *state, 
{

	struct srp_target_port *target = ch->target;

	struct srp_device *dev = target->srp_host->srp_dev;

	struct ib_pd *pd = target->pd;

	struct ib_send_wr *bad_wr;

	struct ib_reg_wr wr;

	struct srp_fr_desc *desc;
@@ -1366,12 +1364,12 @@ static int srp_map_finish_fr(struct srp_map_state *state, 


	WARN_ON_ONCE(!dev->use_fast_reg);



	if (sg_nents == 1 && (pd->flags & IB_PD_UNSAFE_GLOBAL_RKEY)) {

	if (sg_nents == 1 && target->global_rkey) {

		unsigned int sg_offset = sg_offset_p ? *sg_offset_p : 0;



		srp_map_desc(state, sg_dma_address(state->sg) + sg_offset,

			     sg_dma_len(state->sg) - sg_offset,

			     pd->unsafe_global_rkey);

			     target->global_rkey);

		if (sg_offset_p)

			*sg_offset_p = 0;

		return 1;
@@ -1533,7 +1531,7 @@ static int srp_map_sg_dma(struct srp_map_state *state, struct srp_rdma_ch *ch, 
	for_each_sg(scat, sg, count, i) {

		srp_map_desc(state, ib_sg_dma_address(dev->dev, sg),

			     ib_sg_dma_len(dev->dev, sg),

			     target->pd->unsafe_global_rkey);

			     target->global_rkey);

	}



	return 0;
@@ -1631,7 +1629,6 @@ static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_rdma_ch *ch, 
			struct srp_request *req)

{

	struct srp_target_port *target = ch->target;

	struct ib_pd *pd = target->pd;

	struct scatterlist *scat;

	struct srp_cmd *cmd = req->cmd->buf;

	int len, nents, count, ret;
@@ -1667,7 +1664,7 @@ static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_rdma_ch *ch, 
	fmt = SRP_DATA_DESC_DIRECT;

	len = sizeof (struct srp_cmd) +	sizeof (struct srp_direct_buf);



	if (count == 1 && (pd->flags & IB_PD_UNSAFE_GLOBAL_RKEY)) {

	if (count == 1 && target->global_rkey) {

		/*

		 * The midlayer only generated a single gather/scatter

		 * entry, or DMA mapping coalesced everything to a
@@ -1677,7 +1674,7 @@ static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_rdma_ch *ch, 
		struct srp_direct_buf *buf = (void *) cmd->add_data;



		buf->va  = cpu_to_be64(ib_sg_dma_address(ibdev, scat));

		buf->key = cpu_to_be32(pd->unsafe_global_rkey);

		buf->key = cpu_to_be32(target->global_rkey);

		buf->len = cpu_to_be32(ib_sg_dma_len(ibdev, scat));



		req->nmdesc = 0;
@@ -1748,14 +1745,14 @@ static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_rdma_ch *ch, 
	memcpy(indirect_hdr->desc_list, req->indirect_desc,

	       count * sizeof (struct srp_direct_buf));



	if (!(pd->flags & IB_PD_UNSAFE_GLOBAL_RKEY)) {

	if (!target->global_rkey) {

		ret = srp_map_idb(ch, req, state.gen.next, state.gen.end,

				  idb_len, &idb_rkey);

		if (ret < 0)

			goto unmap;

		req->nmdesc++;

	} else {

		idb_rkey = cpu_to_be32(pd->unsafe_global_rkey);

		idb_rkey = cpu_to_be32(target->global_rkey);

	}



	indirect_hdr->table_desc.va = cpu_to_be64(req->indirect_dma_addr);
@@ -3331,8 +3328,8 @@ static ssize_t srp_create_target(struct device *dev, 
	target->io_class	= SRP_REV16A_IB_IO_CLASS;

	target->scsi_host	= target_host;

	target->srp_host	= host;

	target->pd		= host->srp_dev->pd;

	target->lkey		= host->srp_dev->pd->local_dma_lkey;

	target->global_rkey	= host->srp_dev->global_rkey;

	target->cmd_sg_cnt	= cmd_sg_entries;

	target->sg_tablesize	= indirect_sg_entries ? : cmd_sg_entries;

	target->allow_ext_sg	= allow_ext_sg;
@@ -3651,6 +3648,10 @@ static void srp_add_one(struct ib_device *device) 
	if (IS_ERR(srp_dev->pd))

		goto free_dev;



	if (flags & IB_PD_UNSAFE_GLOBAL_RKEY) {

		srp_dev->global_rkey = srp_dev->pd->unsafe_global_rkey;

		WARN_ON_ONCE(srp_dev->global_rkey == 0);

	}



	for (p = rdma_start_port(device); p <= rdma_end_port(device); ++p) {

		host = srp_add_port(srp_dev, p);

drivers/infiniband/ulp/srp/ib_srp.h

+2 −1
Original line number Diff line number Diff line
@@ -90,6 +90,7 @@ struct srp_device { 
	struct list_head	dev_list;

	struct ib_device       *dev;

	struct ib_pd	       *pd;

	u32			global_rkey;

	u64			mr_page_mask;

	int			mr_page_size;

	int			mr_max_size;
@@ -179,7 +180,7 @@ struct srp_target_port { 
	spinlock_t		lock;



	/* read only in the hot path */

	struct ib_pd		*pd;

	u32			global_rkey;

	struct srp_rdma_ch	*ch;

	u32			ch_count;

	u32			lkey;