- Divorce the allocation of free request slots and the congestion
control. Make the congestion control apply only to when we
actually send data over the wire. This means that we *do* apply
congestion control to resent requests: if a timeout has occured,
and there are too many requests on the wire, delay resending until
the congestion algorithm allows it.
- Improve spinlocking by putting the congestion avoidance algoritm
under xprt->sock_lock. This lock has to be taken *anyway* in
(almost) all cases where we are updating the congestion control
data.
Cheers,
Trond
diff -u --recursive --new-file linux-2.5.25-rpc_cong2/net/sunrpc/xprt.c linux-2.5.25-rpc_cong3/net/sunrpc/xprt.c
--- linux-2.5.25-rpc_cong2/net/sunrpc/xprt.c Tue Jul 16 15:46:36 2002
+++ linux-2.5.25-rpc_cong3/net/sunrpc/xprt.c Tue Jul 16 15:32:36 2002
@@ -141,9 +141,11 @@
{
int retval;
spin_lock_bh(&xprt->sock_lock);
- if (!xprt->snd_task)
- xprt->snd_task = task;
- else if (xprt->snd_task != task) {
+ if (!xprt->snd_task) {
+ if (xprt->nocong || __xprt_get_cong(xprt, task))
+ xprt->snd_task = task;
+ }
+ if (xprt->snd_task != task) {
dprintk("RPC: %4d TCP write queue full (task %d)\n",
task->tk_pid, xprt->snd_task->tk_pid);
task->tk_timeout = 0;
@@ -162,10 +164,13 @@
if (xprt->snd_task)
return;
+ if (!xprt->nocong && RPCXPRT_CONGESTED(xprt))
+ return;
task = rpc_wake_up_next(&xprt->sending);
if (!task)
return;
- xprt->snd_task = task;
+ if (xprt->nocong || __xprt_get_cong(xprt, task))
+ xprt->snd_task = task;
}
/*
@@ -297,12 +302,6 @@
{
unsigned long cwnd;
- if (xprt->nocong)
- return;
- /*
- * Note: we're in a BH context
- */
- spin_lock(&xprt->xprt_lock);
cwnd = xprt->cwnd;
if (result >= 0 && xprt->cong <= cwnd) {
/* The (cwnd >> 1) term makes sure
@@ -319,8 +318,6 @@
dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n",
xprt->cong, xprt->cwnd, cwnd);
xprt->cwnd = cwnd;
- out:
- spin_unlock(&xprt->xprt_lock);
}
/*
@@ -534,6 +531,7 @@
/* Adjust congestion window */
if (!xprt->nocong) {
xprt_adjust_cwnd(xprt, copied);
+ __xprt_put_cong(xprt, req);
if (!req->rq_nresend) {
int timer = rpcproc_timer(clnt, task->tk_msg.rpc_proc);
if (timer)
@@ -1011,6 +1009,7 @@
}
rpc_inc_timeo(&task->tk_client->cl_rtt);
xprt_adjust_cwnd(req->rq_xprt, -ETIMEDOUT);
+ __xprt_put_cong(xprt, req);
}
req->rq_nresend++;
@@ -1139,7 +1138,10 @@
req->rq_bytes_sent = 0;
}
out_release:
- xprt_release_write(xprt, task);
+ spin_lock_bh(&xprt->sock_lock);
+ __xprt_release_write(xprt, task);
+ __xprt_put_cong(xprt, req);
+ spin_unlock_bh(&xprt->sock_lock);
return;
out_receive:
dprintk("RPC: %4d xmit complete\n", task->tk_pid);
@@ -1171,7 +1173,7 @@
if (task->tk_rqstp)
return 0;
- spin_lock_bh(&xprt->xprt_lock);
+ spin_lock(&xprt->xprt_lock);
xprt_reserve_status(task);
if (task->tk_rqstp) {
task->tk_timeout = 0;
@@ -1182,7 +1184,7 @@
task->tk_status = -EAGAIN;
rpc_sleep_on(&xprt->backlog, task, NULL, NULL);
}
- spin_unlock_bh(&xprt->xprt_lock);
+ spin_unlock(&xprt->xprt_lock);
dprintk("RPC: %4d xprt_reserve returns %d\n",
task->tk_pid, task->tk_status);
return task->tk_status;
@@ -1206,17 +1208,11 @@
} else {
if (!(req = xprt->free))
goto out_nofree;
- if (!(xprt->nocong || __xprt_get_cong(xprt, req)))
- goto out_nofree;
- /* OK: There's room for us. Grab a free slot and bump
- * congestion value */
+ /* OK: There's room for us. Grab a free slot */
xprt->free = req->rq_next;
req->rq_next = NULL;
task->tk_rqstp = req;
xprt_request_init(task, xprt);
-
- if (xprt->free)
- xprt_clear_backlog(xprt);
}
return;
@@ -1264,6 +1260,7 @@
return;
spin_lock_bh(&xprt->sock_lock);
__xprt_release_write(xprt, task);
+ __xprt_put_cong(xprt, req);
if (!list_empty(&req->rq_list))
list_del(&req->rq_list);
spin_unlock_bh(&xprt->sock_lock);
@@ -1272,13 +1269,12 @@
dprintk("RPC: %4d release request %p\n", task->tk_pid, req);
- spin_lock_bh(&xprt->xprt_lock);
+ spin_lock(&xprt->xprt_lock);
req->rq_next = xprt->free;
xprt->free = req;
- __xprt_put_cong(xprt, req);
xprt_clear_backlog(xprt);
- spin_unlock_bh(&xprt->xprt_lock);
+ spin_unlock(&xprt->xprt_lock);
}
/*
@@ -1492,8 +1488,6 @@
*/
int
xprt_clear_backlog(struct rpc_xprt *xprt) {
- if (RPCXPRT_CONGESTED(xprt))
- return 0;
rpc_wake_up_next(&xprt->backlog);
if (waitqueue_active(&xprt->cong_wait))
wake_up(&xprt->cong_wait);
-
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This archive was generated by hypermail 2b29 : Tue Jul 23 2002 - 22:00:20 EST