Commit 87cfb9a0 authored by Chuck Lever's avatar Chuck Lever Committed by Anna Schumaker
Browse files

xprtrdma: Client-side support for rpcrdma_connect_private 



Send an RDMA-CM private message on connect, and look for one during
a connection-established event.

Both sides can communicate their various implementation limits.
Implementations that don't support this sideband protocol ignore it.

Once the client knows the server's inline threshold maxima, it can
adjust the use of Reply chunks, and eliminate most use of Position
Zero Read chunks. Moderately-sized I/O can be done using a pure
inline RDMA Send instead of RDMA operations that require memory
registration.

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent ff06bd19

include/linux/sunrpc/rpc_rdma.h

+4 −0
Original line number Diff line number Diff line
@@ -46,6 +46,10 @@ 
#define RPCRDMA_VERSION		1

#define rpcrdma_version		cpu_to_be32(RPCRDMA_VERSION)



enum {

	RPCRDMA_V1_DEF_INLINE_SIZE	= 1024,

};



struct rpcrdma_segment {

	__be32 rs_handle;	/* Registered memory handle */

	__be32 rs_length;	/* Length of the chunk in bytes */

net/sunrpc/xprtrdma/fmr_ops.c

+2 −3
Original line number Diff line number Diff line
@@ -160,9 +160,8 @@ static int 
fmr_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep,

	    struct rpcrdma_create_data_internal *cdata)

{

	rpcrdma_set_max_header_sizes(ia, cdata, max_t(unsigned int, 1,

						      RPCRDMA_MAX_DATA_SEGS /

						      RPCRDMA_MAX_FMR_SGES));

	ia->ri_max_segs = max_t(unsigned int, 1, RPCRDMA_MAX_DATA_SEGS /

				RPCRDMA_MAX_FMR_SGES);

	return 0;

}

net/sunrpc/xprtrdma/frwr_ops.c

+2 −3
Original line number Diff line number Diff line
@@ -242,9 +242,8 @@ frwr_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep, 
					       depth;

	}



	rpcrdma_set_max_header_sizes(ia, cdata, max_t(unsigned int, 1,

						      RPCRDMA_MAX_DATA_SEGS /

						      ia->ri_max_frmr_depth));

	ia->ri_max_segs = max_t(unsigned int, 1, RPCRDMA_MAX_DATA_SEGS /

				ia->ri_max_frmr_depth);

	return 0;

}

net/sunrpc/xprtrdma/rpc_rdma.c

+5 −3
Original line number Diff line number Diff line
@@ -118,10 +118,12 @@ static unsigned int rpcrdma_max_reply_header_size(unsigned int maxsegs) 
	return size;

}



void rpcrdma_set_max_header_sizes(struct rpcrdma_ia *ia,

				  struct rpcrdma_create_data_internal *cdata,

				  unsigned int maxsegs)

void rpcrdma_set_max_header_sizes(struct rpcrdma_xprt *r_xprt)

{

	struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;

	struct rpcrdma_ia *ia = &r_xprt->rx_ia;

	unsigned int maxsegs = ia->ri_max_segs;



	ia->ri_max_inline_write = cdata->inline_wsize -

				  rpcrdma_max_call_header_size(maxsegs);

	ia->ri_max_inline_read = cdata->inline_rsize -

net/sunrpc/xprtrdma/verbs.c

+37 −3
Original line number Diff line number Diff line
@@ -204,6 +204,33 @@ out_fail: 
	goto out_schedule;

}



static void

rpcrdma_update_connect_private(struct rpcrdma_xprt *r_xprt,

			       struct rdma_conn_param *param)

{

	struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;

	const struct rpcrdma_connect_private *pmsg = param->private_data;

	unsigned int rsize, wsize;



	rsize = RPCRDMA_V1_DEF_INLINE_SIZE;

	wsize = RPCRDMA_V1_DEF_INLINE_SIZE;



	if (pmsg &&

	    pmsg->cp_magic == rpcrdma_cmp_magic &&

	    pmsg->cp_version == RPCRDMA_CMP_VERSION) {

		rsize = rpcrdma_decode_buffer_size(pmsg->cp_send_size);

		wsize = rpcrdma_decode_buffer_size(pmsg->cp_recv_size);

	}



	if (rsize < cdata->inline_rsize)

		cdata->inline_rsize = rsize;

	if (wsize < cdata->inline_wsize)

		cdata->inline_wsize = wsize;

	pr_info("rpcrdma: max send %u, max recv %u\n",

		cdata->inline_wsize, cdata->inline_rsize);

	rpcrdma_set_max_header_sizes(r_xprt);

}



static int

rpcrdma_conn_upcall(struct rdma_cm_id *id, struct rdma_cm_event *event)

{
@@ -244,6 +271,7 @@ rpcrdma_conn_upcall(struct rdma_cm_id *id, struct rdma_cm_event *event) 
			" (%d initiator)\n",

			__func__, attr->max_dest_rd_atomic,

			attr->max_rd_atomic);

		rpcrdma_update_connect_private(xprt, &event->param.conn);

		goto connected;

	case RDMA_CM_EVENT_CONNECT_ERROR:

		connstate = -ENOTCONN;
@@ -454,6 +482,7 @@ int 
rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,

				struct rpcrdma_create_data_internal *cdata)

{

	struct rpcrdma_connect_private *pmsg = &ep->rep_cm_private;

	struct ib_cq *sendcq, *recvcq;

	unsigned int max_qp_wr;

	int rc;
@@ -536,9 +565,14 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia, 
	/* Initialize cma parameters */

	memset(&ep->rep_remote_cma, 0, sizeof(ep->rep_remote_cma));



	/* RPC/RDMA does not use private data */

	ep->rep_remote_cma.private_data = NULL;

	ep->rep_remote_cma.private_data_len = 0;

	/* Prepare RDMA-CM private message */

	pmsg->cp_magic = rpcrdma_cmp_magic;

	pmsg->cp_version = RPCRDMA_CMP_VERSION;

	pmsg->cp_flags = 0;

	pmsg->cp_send_size = rpcrdma_encode_buffer_size(cdata->inline_wsize);

	pmsg->cp_recv_size = rpcrdma_encode_buffer_size(cdata->inline_rsize);

	ep->rep_remote_cma.private_data = pmsg;

	ep->rep_remote_cma.private_data_len = sizeof(*pmsg);



	/* Client offers RDMA Read but does not initiate */

	ep->rep_remote_cma.initiator_depth = 0;

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