Commit 6ceea368 authored by Chuck Lever's avatar Chuck Lever Committed by Anna Schumaker
Browse files

xprtrdma: Refactor Receive accounting 



Clean up: Divide the work cleanly:

- rpcrdma_wc_receive is responsible only for RDMA Receives
- rpcrdma_reply_handler is responsible only for RPC Replies
- the posted send and receive counts both belong in rpcrdma_ep

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent b674c4b4

include/trace/events/rpcrdma.h

+1 −1
Original line number Diff line number Diff line
@@ -570,7 +570,7 @@ TRACE_EVENT(xprtrdma_post_recvs, 
		__entry->r_xprt = r_xprt;

		__entry->count = count;

		__entry->status = status;

		__entry->posted = r_xprt->rx_buf.rb_posted_receives;

		__entry->posted = r_xprt->rx_ep.rep_receive_count;

		__assign_str(addr, rpcrdma_addrstr(r_xprt));

		__assign_str(port, rpcrdma_portstr(r_xprt));

	),

net/sunrpc/xprtrdma/backchannel.c

+0 −1
Original line number Diff line number Diff line
@@ -207,7 +207,6 @@ int xprt_rdma_bc_send_reply(struct rpc_rqst *rqst) 
	if (rc < 0)

		goto failed_marshal;



	rpcrdma_post_recvs(r_xprt, true);

	if (rpcrdma_ep_post(&r_xprt->rx_ia, &r_xprt->rx_ep, req))

		goto drop_connection;

	return 0;

net/sunrpc/xprtrdma/rpc_rdma.c

+3 −18
Original line number Diff line number Diff line
@@ -1312,11 +1312,6 @@ void rpcrdma_reply_handler(struct rpcrdma_rep *rep) 
	u32 credits;

	__be32 *p;



	--buf->rb_posted_receives;



	if (rep->rr_hdrbuf.head[0].iov_len == 0)

		goto out_badstatus;



	/* Fixed transport header fields */

	xdr_init_decode(&rep->rr_stream, &rep->rr_hdrbuf,

			rep->rr_hdrbuf.head[0].iov_base);
@@ -1361,31 +1356,21 @@ void rpcrdma_reply_handler(struct rpcrdma_rep *rep) 
	clear_bit(RPCRDMA_REQ_F_PENDING, &req->rl_flags);



	trace_xprtrdma_reply(rqst->rq_task, rep, req, credits);



	rpcrdma_post_recvs(r_xprt, false);

	queue_work(rpcrdma_receive_wq, &rep->rr_work);

	return;



out_badversion:

	trace_xprtrdma_reply_vers(rep);

	goto repost;

	goto out;



/* The RPC transaction has already been terminated, or the header

 * is corrupt.

 */

out_norqst:

	spin_unlock(&xprt->queue_lock);

	trace_xprtrdma_reply_rqst(rep);

	goto repost;

	goto out;



out_shortreply:

	trace_xprtrdma_reply_short(rep);



/* If no pending RPC transaction was matched, post a replacement

 * receive buffer before returning.

 */

repost:

	rpcrdma_post_recvs(r_xprt, false);

out_badstatus:

out:

	rpcrdma_recv_buffer_put(rep);

}

net/sunrpc/xprtrdma/verbs.c

+14 −17
Original line number Diff line number Diff line
@@ -78,6 +78,7 @@ static void rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt); 
static void rpcrdma_mrs_destroy(struct rpcrdma_buffer *buf);

static int rpcrdma_create_rep(struct rpcrdma_xprt *r_xprt, bool temp);

static void rpcrdma_dma_unmap_regbuf(struct rpcrdma_regbuf *rb);

static void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp);



struct workqueue_struct *rpcrdma_receive_wq __read_mostly;
@@ -189,11 +190,13 @@ rpcrdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc) 
	struct ib_cqe *cqe = wc->wr_cqe;

	struct rpcrdma_rep *rep = container_of(cqe, struct rpcrdma_rep,

					       rr_cqe);

	struct rpcrdma_xprt *r_xprt = rep->rr_rxprt;



	/* WARNING: Only wr_id and status are reliable at this point */

	/* WARNING: Only wr_cqe and status are reliable at this point */

	trace_xprtrdma_wc_receive(wc);

	--r_xprt->rx_ep.rep_receive_count;

	if (wc->status != IB_WC_SUCCESS)

		goto out_fail;

		goto out_flushed;



	/* status == SUCCESS means all fields in wc are trustworthy */

	rpcrdma_set_xdrlen(&rep->rr_hdrbuf, wc->byte_len);
@@ -204,17 +207,16 @@ rpcrdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc) 
				   rdmab_addr(rep->rr_rdmabuf),

				   wc->byte_len, DMA_FROM_DEVICE);



out_schedule:

	rpcrdma_post_recvs(r_xprt, false);

	rpcrdma_reply_handler(rep);

	return;



out_fail:

out_flushed:

	if (wc->status != IB_WC_WR_FLUSH_ERR)

		pr_err("rpcrdma: Recv: %s (%u/0x%x)\n",

		       ib_wc_status_msg(wc->status),

		       wc->status, wc->vendor_err);

	rpcrdma_set_xdrlen(&rep->rr_hdrbuf, 0);

	goto out_schedule;

	rpcrdma_recv_buffer_put(rep);

}



static void
@@ -581,6 +583,7 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia, 
	init_waitqueue_head(&ep->rep_connect_wait);

	INIT_DELAYED_WORK(&ep->rep_disconnect_worker,

			  rpcrdma_disconnect_worker);

	ep->rep_receive_count = 0;



	sendcq = ib_alloc_cq(ia->ri_device, NULL,

			     ep->rep_attr.cap.max_send_wr + 1,
@@ -1174,7 +1177,6 @@ rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt) 
	}



	buf->rb_credits = 1;

	buf->rb_posted_receives = 0;

	INIT_LIST_HEAD(&buf->rb_recv_bufs);



	rc = rpcrdma_sendctxs_create(r_xprt);
@@ -1511,25 +1513,20 @@ rpcrdma_ep_post(struct rpcrdma_ia *ia, 
	return 0;

}



/**

 * rpcrdma_post_recvs - Maybe post some Receive buffers

 * @r_xprt: controlling transport

 * @temp: when true, allocate temp rpcrdma_rep objects

 *

 */

void

static void

rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp)

{

	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;

	struct rpcrdma_ep *ep = &r_xprt->rx_ep;

	struct ib_recv_wr *wr, *bad_wr;

	int needed, count, rc;



	rc = 0;

	count = 0;

	needed = buf->rb_credits + (buf->rb_bc_srv_max_requests << 1);

	if (buf->rb_posted_receives > needed)

	if (ep->rep_receive_count > needed)

		goto out;

	needed -= buf->rb_posted_receives;

	needed -= ep->rep_receive_count;



	count = 0;

	wr = NULL;
@@ -1577,7 +1574,7 @@ rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp) 
			--count;

		}

	}

	buf->rb_posted_receives += count;

	ep->rep_receive_count += count;

out:

	trace_xprtrdma_post_recvs(r_xprt, count, rc);

}

net/sunrpc/xprtrdma/xprt_rdma.h

+1 −2
Original line number Diff line number Diff line
@@ -102,6 +102,7 @@ struct rpcrdma_ep { 
	struct rpcrdma_connect_private	rep_cm_private;

	struct rdma_conn_param	rep_remote_cma;

	struct delayed_work	rep_disconnect_worker;

	int			rep_receive_count;

};



/* Pre-allocate extra Work Requests for handling backward receives
@@ -404,7 +405,6 @@ struct rpcrdma_buffer { 
	unsigned long		rb_flags;

	u32			rb_max_requests;

	u32			rb_credits;	/* most recent credit grant */

	int			rb_posted_receives;



	u32			rb_bc_srv_max_requests;

	spinlock_t		rb_reqslock;	/* protect rb_allreqs */
@@ -560,7 +560,6 @@ void rpcrdma_ep_disconnect(struct rpcrdma_ep *, struct rpcrdma_ia *); 


int rpcrdma_ep_post(struct rpcrdma_ia *, struct rpcrdma_ep *,

				struct rpcrdma_req *);

void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp);



/*

 * Buffer calls - xprtrdma/verbs.c

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