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>

1 files changed, 19 insertions, 12 deletions

diff --git a/drivers/infiniband/ulp/srp/ib_srp.h b/drivers/infiniband/ulp/srp/ib_srp.h
index acb435d3c1e3..9dc6fc3fd894 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_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 @@ 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;