xprtrdma: Initialize rb_credits in one place

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>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
This commit is contained in:
Chuck Lever 2019-10-09 13:07:32 -04:00 committed by Anna Schumaker
parent a31b2f9392
commit eea63ca7ff
4 changed files with 38 additions and 16 deletions

View File

@ -916,6 +916,40 @@ out_err:
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) {

View File

@ -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;

View File

@ -727,6 +727,7 @@ retry:
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);

View File

@ -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);