From: Chuck Lever <chuck.lever@oracle.com>
To: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org
Subject: [PATCH v1 3/6] xprtrdma: Initialize rb_credits in one place
Date: Wed, 09 Oct 2019 13:07:32 -0400 [thread overview]
Message-ID: <20191009170732.2978.21414.stgit@manet.1015granger.net> (raw)
In-Reply-To: <20191009170721.2978.128.stgit@manet.1015granger.net>
Clean up/code de-duplication.
Nit: RPC_CWNDSHIFT is incorrect as the initial value for xprt->cwnd.
This mistake does not appear to have operational consequences, since
the cwnd value is replaced with a valid value upon the first Receive
completion.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
net/sunrpc/xprtrdma/rpc_rdma.c | 42 +++++++++++++++++++++++++++++++++------
net/sunrpc/xprtrdma/transport.c | 9 --------
net/sunrpc/xprtrdma/verbs.c | 2 +-
net/sunrpc/xprtrdma/xprt_rdma.h | 1 +
4 files changed, 38 insertions(+), 16 deletions(-)
diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index b86b5fd..f1e3639 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -916,6 +916,40 @@ static bool rpcrdma_prepare_msg_sges(struct rpcrdma_xprt *r_xprt,
return ret;
}
+static void __rpcrdma_update_cwnd_locked(struct rpc_xprt *xprt,
+ struct rpcrdma_buffer *buf,
+ u32 grant)
+{
+ buf->rb_credits = grant;
+ xprt->cwnd = grant << RPC_CWNDSHIFT;
+}
+
+static void rpcrdma_update_cwnd(struct rpcrdma_xprt *r_xprt, u32 grant)
+{
+ struct rpc_xprt *xprt = &r_xprt->rx_xprt;
+
+ spin_lock(&xprt->transport_lock);
+ __rpcrdma_update_cwnd_locked(xprt, &r_xprt->rx_buf, grant);
+ spin_unlock(&xprt->transport_lock);
+}
+
+/**
+ * rpcrdma_reset_cwnd - Reset the xprt's congestion window
+ * @r_xprt: controlling transport instance
+ *
+ * Prepare @r_xprt for the next connection by reinitializing
+ * its credit grant to one (see RFC 8166, Section 3.3.3).
+ */
+void rpcrdma_reset_cwnd(struct rpcrdma_xprt *r_xprt)
+{
+ struct rpc_xprt *xprt = &r_xprt->rx_xprt;
+
+ spin_lock(&xprt->transport_lock);
+ xprt->cong = 0;
+ __rpcrdma_update_cwnd_locked(xprt, &r_xprt->rx_buf, 1);
+ spin_unlock(&xprt->transport_lock);
+}
+
/**
* rpcrdma_inline_fixup - Scatter inline received data into rqst's iovecs
* @rqst: controlling RPC request
@@ -1356,12 +1390,8 @@ void rpcrdma_reply_handler(struct rpcrdma_rep *rep)
credits = 1; /* don't deadlock */
else if (credits > buf->rb_max_requests)
credits = buf->rb_max_requests;
- if (buf->rb_credits != credits) {
- spin_lock(&xprt->transport_lock);
- buf->rb_credits = credits;
- xprt->cwnd = credits << RPC_CWNDSHIFT;
- spin_unlock(&xprt->transport_lock);
- }
+ if (buf->rb_credits != credits)
+ rpcrdma_update_cwnd(r_xprt, credits);
req = rpcr_to_rdmar(rqst);
if (req->rl_reply) {
diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c
index c67d465..0711308 100644
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -425,15 +425,6 @@ void xprt_rdma_close(struct rpc_xprt *xprt)
return;
rpcrdma_ep_disconnect(ep, ia);
- /* Prepare @xprt for the next connection by reinitializing
- * its credit grant to one (see RFC 8166, Section 3.3.3).
- */
- spin_lock(&xprt->transport_lock);
- r_xprt->rx_buf.rb_credits = 1;
- xprt->cong = 0;
- xprt->cwnd = RPC_CWNDSHIFT;
- spin_unlock(&xprt->transport_lock);
-
out:
xprt->reestablish_timeout = 0;
++xprt->connect_cookie;
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index f4b1365..97bc15e 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -727,6 +727,7 @@ static int rpcrdma_ep_reconnect(struct rpcrdma_xprt *r_xprt,
ep->rep_connected = 0;
xprt_clear_connected(xprt);
+ rpcrdma_reset_cwnd(r_xprt);
rpcrdma_post_recvs(r_xprt, true);
rc = rdma_connect(ia->ri_id, &ep->rep_remote_cma);
@@ -1163,7 +1164,6 @@ int rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
list_add(&req->rl_list, &buf->rb_send_bufs);
}
- buf->rb_credits = 1;
init_llist_head(&buf->rb_free_reps);
rc = rpcrdma_sendctxs_create(r_xprt);
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 65e6b0e..b170cf5 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -576,6 +576,7 @@ int rpcrdma_prepare_send_sges(struct rpcrdma_xprt *r_xprt,
void rpcrdma_sendctx_unmap(struct rpcrdma_sendctx *sc);
int rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst);
void rpcrdma_set_max_header_sizes(struct rpcrdma_xprt *);
+void rpcrdma_reset_cwnd(struct rpcrdma_xprt *r_xprt);
void rpcrdma_complete_rqst(struct rpcrdma_rep *rep);
void rpcrdma_reply_handler(struct rpcrdma_rep *rep);
next prev parent reply other threads:[~2019-10-09 17:07 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-09 17:07 [PATCH v1 1/6] xprtrdma: Add unique trace points for posting Local Invalidate WRs Chuck Lever
2019-10-09 17:07 ` [PATCH v1 2/6] xprtrdma: Connection becomes unstable after a reconnect Chuck Lever
2019-10-09 17:07 ` Chuck Lever [this message]
2019-10-09 17:07 ` [PATCH v1 4/6] xprtrdma: Close window between waking RPC senders and posting Receives Chuck Lever
2019-10-09 17:07 ` [PATCH v1 5/6] xprtrdma: Fix MR list handling Chuck Lever
2019-10-09 17:07 ` [PATCH v1 6/6] xprtrdma: Manage MRs in context of a single connection Chuck Lever
2019-10-09 17:10 ` [PATCH v1 1/6] xprtrdma: Add unique trace points for posting Local Invalidate WRs Chuck Lever
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