net/rds: Use DMA memory pool allocation for rds_header
Currently, RDS calls ib_dma_alloc_coherent() to allocate a large piece
of contiguous DMA coherent memory to store struct rds_header for
sending/receiving packets. The memory allocated is then partitioned
into struct rds_header. This is not necessary and can be costly at
times when memory is fragmented. Instead, RDS should use the DMA
memory pool interface to handle this. The DMA addresses of the pre-
allocated headers are stored in an array. At send/receive ring
initialization and refill time, this arrary is de-referenced to get
the DMA addresses. This array is not accessed at send/receive packet
processing.
Suggested-by: Håkon Bugge <haakon.bugge@oracle.com>
Signed-off-by: Ka-Cheong Poon <ka-cheong.poon@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/rds/ib.h b/net/rds/ib.h
index f2b558e..6e6f247 100644
--- a/net/rds/ib.h
+++ b/net/rds/ib.h
@@ -165,8 +165,8 @@ struct rds_ib_connection {
/* tx */
struct rds_ib_work_ring i_send_ring;
struct rm_data_op *i_data_op;
- struct rds_header *i_send_hdrs;
- dma_addr_t i_send_hdrs_dma;
+ struct rds_header **i_send_hdrs;
+ dma_addr_t *i_send_hdrs_dma;
struct rds_ib_send_work *i_sends;
atomic_t i_signaled_sends;
@@ -175,8 +175,8 @@ struct rds_ib_connection {
struct rds_ib_work_ring i_recv_ring;
struct rds_ib_incoming *i_ibinc;
u32 i_recv_data_rem;
- struct rds_header *i_recv_hdrs;
- dma_addr_t i_recv_hdrs_dma;
+ struct rds_header **i_recv_hdrs;
+ dma_addr_t *i_recv_hdrs_dma;
struct rds_ib_recv_work *i_recvs;
u64 i_ack_recv; /* last ACK received */
struct rds_ib_refill_cache i_cache_incs;
@@ -246,6 +246,7 @@ struct rds_ib_device {
struct list_head conn_list;
struct ib_device *dev;
struct ib_pd *pd;
+ struct dma_pool *rid_hdrs_pool; /* RDS headers DMA pool */
bool use_fastreg;
unsigned int max_mrs;
@@ -381,7 +382,11 @@ int rds_ib_cm_handle_connect(struct rdma_cm_id *cm_id,
int rds_ib_cm_initiate_connect(struct rdma_cm_id *cm_id, bool isv6);
void rds_ib_cm_connect_complete(struct rds_connection *conn,
struct rdma_cm_event *event);
-
+struct rds_header **rds_dma_hdrs_alloc(struct ib_device *ibdev,
+ struct dma_pool *pool,
+ dma_addr_t **dma_addrs, u32 num_hdrs);
+void rds_dma_hdrs_free(struct dma_pool *pool, struct rds_header **hdrs,
+ dma_addr_t *dma_addrs, u32 num_hdrs);
#define rds_ib_conn_error(conn, fmt...) \
__rds_ib_conn_error(conn, KERN_WARNING "RDS/IB: " fmt)