Put the variables accessed together in the hot-path into common
cachelines, and separate them by RW vs RO to avoid false dirtying.
We keep a local copy of the lkey and rkey in the target to avoid
traversing pointers (and associated cache lines) to find them.
---
drivers/infiniband/ulp/srp/ib_srp.c | 12 +++++++-----
drivers/infiniband/ulp/srp/ib_srp.h | 31 +++++++++++++++++++------------
2 files changed, 26 insertions(+), 17 deletions(-)
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index fff72c8..cef6191 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -768,7 +768,7 @@ static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_target_port *target,
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(dev->mr->rkey);
+ buf->key = cpu_to_be32(target->rkey);
buf->len = cpu_to_be32(ib_sg_dma_len(ibdev, scat));
} else if (srp_map_fmr(target, scat, count, req,
(void *) cmd->add_data)) {
@@ -793,7 +793,7 @@ static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_target_port *target,
buf->desc_list[i].va =
cpu_to_be64(ib_sg_dma_address(ibdev, sg));
buf->desc_list[i].key =
- cpu_to_be32(dev->mr->rkey);
+ cpu_to_be32(target->rkey);
buf->desc_list[i].len = cpu_to_be32(dma_len);
datalen += dma_len;
}
@@ -806,7 +806,7 @@ static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_target_port *target,
buf->table_desc.va =
cpu_to_be64(req->cmd->dma + sizeof *cmd + sizeof *buf);
buf->table_desc.key =
- cpu_to_be32(target->srp_host->srp_dev->mr->rkey);
+ cpu_to_be32(target->rkey);
buf->table_desc.len =
cpu_to_be32(count * sizeof (struct srp_direct_buf));
@@ -883,7 +883,7 @@ static int srp_post_send(struct srp_target_port *target,
list.addr = iu->dma;
list.length = len;
- list.lkey = target->srp_host->srp_dev->mr->lkey;
+ list.lkey = target->lkey;
wr.next = NULL;
wr.wr_id = (uintptr_t) iu;
@@ -902,7 +902,7 @@ static int srp_post_recv(struct srp_target_port *target, struct srp_iu *iu)
list.addr = iu->dma;
list.length = iu->size;
- list.lkey = target->srp_host->srp_dev->mr->lkey;
+ list.lkey = target->lkey;
wr.next = NULL;
wr.wr_id = (uintptr_t) iu;
@@ -1953,6 +1953,8 @@ 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->lkey = host->srp_dev->mr->lkey;
+ target->rkey = host->srp_dev->mr->rkey;
spin_lock_init(&target->lock);
INIT_LIST_HEAD(&target->free_tx);
diff --git a/drivers/infiniband/ulp/srp/ib_srp.h b/drivers/infiniband/ulp/srp/ib_srp.h
index c4699ea..43f9129 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.h
+++ b/drivers/infiniband/ulp/srp/ib_srp.h
@@ -117,6 +117,24 @@ struct srp_request {
};
struct srp_target_port {
+ /* These are RW in the hot path, and commonly used together */
+ struct list_head free_tx;
+ struct list_head free_reqs;
+ spinlock_t lock;
+ s32 req_lim;
+
+ /* These are read-only in the hot path */
+ struct ib_cq *send_cq ____cacheline_aligned;
+ struct ib_cq *recv_cq;
+ struct ib_qp *qp;
+ u32 lkey;
+ u32 rkey;
+ enum srp_target_state state;
+
+ /* Everything above this point is used in the hot path of
+ * command processing. Try to keep them packed into cachelines.
+ */
+
__be64 id_ext;
__be64 ioc_guid;
__be64 service_id;
@@ -133,23 +151,13 @@ struct srp_target_port {
int path_query_id;
struct ib_cm_id *cm_id;
- struct ib_cq *recv_cq;
- struct ib_cq *send_cq;
- struct ib_qp *qp;
int max_ti_iu_len;
- s32 req_lim;
int zero_req_lim;
- struct srp_iu *rx_ring[SRP_RQ_SIZE];
-
- spinlock_t lock;
-
- struct list_head free_tx;
struct srp_iu *tx_ring[SRP_SQ_SIZE];
-
- struct list_head free_reqs;
+ struct srp_iu *rx_ring[SRP_RQ_SIZE];
struct srp_request req_ring[SRP_CMD_SQ_SIZE];
struct work_struct work;
@@ -157,7 +165,6 @@ struct srp_target_port {
struct list_head list;
struct completion done;
int status;
- enum srp_target_state state;
int qp_in_error;
struct completion tsk_mgmt_done;
--
1.7.2.3
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