svcrdma: Reduce size of sge array in struct svc_rdma_op_ctxt

The sge array in struct svc_rdma_op_ctxt is no longer used for
sending RDMA Write WRs. It need only accommodate the construction of
Send and Receive WRs. The maximum inline size is the largest payload
it needs to handle now.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h
index 44d642bbfce68c6cf4114d66ce1a76f0ed805df7..e84b7755678472269ca578b2358310cb837d9544 100644 (file)
--- a/include/linux/sunrpc/svc_rdma.h
+++ b/include/linux/sunrpc/svc_rdma.h
@@ -48,6 +48,12 @@
 #include <rdma/rdma_cm.h>
 #define SVCRDMA_DEBUG
 
+/* Default and maximum inline threshold sizes */
+enum {
+       RPCRDMA_DEF_INLINE_THRESH = 4096,
+       RPCRDMA_MAX_INLINE_THRESH = 65536
+};
+
 /* RPC/RDMA parameters and stats */
 extern unsigned int svcrdma_ord;
 extern unsigned int svcrdma_max_requests;
@@ -86,7 +92,7 @@ struct svc_rdma_op_ctxt {
        int count;
        unsigned int mapped_sges;
        struct ib_send_wr send_wr;
-       struct ib_sge sge[RPCSVC_MAXPAGES];
+       struct ib_sge sge[1 + RPCRDMA_MAX_INLINE_THRESH / PAGE_SIZE];
        struct page *pages[RPCSVC_MAXPAGES];
 };
 
@@ -186,7 +192,6 @@ struct svcxprt_rdma {
  * page size of 4k, or 32k * 2 ops / 4k = 16 outstanding RDMA_READ.  */
 #define RPCRDMA_ORD             (64/4)
 #define RPCRDMA_MAX_REQUESTS    32
-#define RPCRDMA_MAX_REQ_SIZE    4096
 
 /* Typical ULP usage of BC requests is NFSv4.1 backchannel. Our
  * current NFSv4.1 implementation supports one backchannel slot.

diff --git a/net/sunrpc/xprtrdma/svc_rdma.c b/net/sunrpc/xprtrdma/svc_rdma.c
index 9124441746470c0d7e8da3d31d68eddead04b8c2..a4a8f6989ee747a1a5046e1e5cff92a0ca167775 100644 (file)
--- a/net/sunrpc/xprtrdma/svc_rdma.c
+++ b/net/sunrpc/xprtrdma/svc_rdma.c
@@ -58,9 +58,9 @@ unsigned int svcrdma_max_requests = RPCRDMA_MAX_REQUESTS;
 unsigned int svcrdma_max_bc_requests = RPCRDMA_MAX_BC_REQUESTS;
 static unsigned int min_max_requests = 4;
 static unsigned int max_max_requests = 16384;
-unsigned int svcrdma_max_req_size = RPCRDMA_MAX_REQ_SIZE;
-static unsigned int min_max_inline = 4096;
-static unsigned int max_max_inline = 65536;
+unsigned int svcrdma_max_req_size = RPCRDMA_DEF_INLINE_THRESH;
+static unsigned int min_max_inline = RPCRDMA_DEF_INLINE_THRESH;
+static unsigned int max_max_inline = RPCRDMA_MAX_INLINE_THRESH;
 
 atomic_t rdma_stat_recv;
 atomic_t rdma_stat_read;