IB/srp: Cache global rkey

This is a micro-optimization for the hot path.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This commit is contained in:
Bart Van Assche 2017-10-11 10:27:28 -07:00 committed by Doug Ledford
parent 9566b05492
commit cee687b68d
2 changed files with 16 additions and 14 deletions

View File

@ -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);

View File

@ -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;