IB/srp: consolidate hot-path variables into cache lines
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.
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: David Dillow <dillowda@ornl.gov>
diff --git a/drivers/infiniband/ulp/srp/ib_srp.h b/drivers/infiniband/ulp/srp/ib_srp.h
index acb435d..9dc6fc3 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.h
+++ b/drivers/infiniband/ulp/srp/ib_srp.h
@@ -117,6 +117,24 @@
};
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_in_smp;
+ 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 @@
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 list_head list;
struct completion done;
int status;
- enum srp_target_state state;
int qp_in_error;
struct completion tsk_mgmt_done;