From: Trond Myklebust <trond.myklebust@fys.uio.no>
I can never guarantee you perfect service with soft mounts (a 5 second
network patition/server congestion is all it takes) but I do have a
patch that just went into 2.4.22 that backs out some of the
Van Jacobson exponential backoff changes. This helps stabilize things
a lot.
I haven't yet had time to port that patch to 2.5.x, but the code
should be pretty much identical, so if you want to give it a go, then
here it is...
net/sunrpc/clnt.c | 4 ++--
net/sunrpc/xprt.c | 30 ++++--------------------------
2 files changed, 6 insertions(+), 28 deletions(-)
diff -puN net/sunrpc/clnt.c~nfs-revert-backoff net/sunrpc/clnt.c
--- 25/net/sunrpc/clnt.c~nfs-revert-backoff 2003-07-31 22:08:57.000000000 -0700
+++ 25-akpm/net/sunrpc/clnt.c 2003-07-31 22:08:57.000000000 -0700
@@ -744,14 +744,14 @@ call_timeout(struct rpc_task *task)
dprintk("RPC: %4d call_timeout (major)\n", task->tk_pid);
if (clnt->cl_softrtry) {
- if (clnt->cl_chatty && !task->tk_exit)
+ if (clnt->cl_chatty)
printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
clnt->cl_protname, clnt->cl_server);
rpc_exit(task, -EIO);
return;
}
- if (clnt->cl_chatty && !(task->tk_flags & RPC_CALL_MAJORSEEN) && rpc_ntimeo(&clnt->cl_rtt) > 7) {
+ if (clnt->cl_chatty && !(task->tk_flags & RPC_CALL_MAJORSEEN)) {
task->tk_flags |= RPC_CALL_MAJORSEEN;
printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
clnt->cl_protname, clnt->cl_server);
diff -puN net/sunrpc/xprt.c~nfs-revert-backoff net/sunrpc/xprt.c
--- 25/net/sunrpc/xprt.c~nfs-revert-backoff 2003-07-31 22:08:57.000000000 -0700
+++ 25-akpm/net/sunrpc/xprt.c 2003-07-31 22:08:57.000000000 -0700
@@ -1040,21 +1040,6 @@ out:
}
/*
- * Exponential backoff for UDP retries
- */
-static inline int
-xprt_expbackoff(struct rpc_task *task, struct rpc_rqst *req)
-{
- int backoff;
-
- req->rq_ntimeo++;
- backoff = min(rpc_ntimeo(&task->tk_client->cl_rtt), XPRT_MAX_BACKOFF);
- if (req->rq_ntimeo < (1 << backoff))
- return 1;
- return 0;
-}
-
-/*
* RPC receive timeout handler.
*/
static void
@@ -1067,14 +1052,7 @@ xprt_timer(struct rpc_task *task)
if (req->rq_received)
goto out;
- if (!xprt->nocong) {
- if (xprt_expbackoff(task, req)) {
- rpc_add_timer(task, xprt_timer);
- goto out_unlock;
- }
- rpc_inc_timeo(&task->tk_client->cl_rtt);
- xprt_adjust_cwnd(req->rq_xprt, -ETIMEDOUT);
- }
+ xprt_adjust_cwnd(req->rq_xprt, -ETIMEDOUT);
req->rq_nresend++;
dprintk("RPC: %4d xprt_timer (%s request)\n",
@@ -1084,7 +1062,6 @@ xprt_timer(struct rpc_task *task)
out:
task->tk_timeout = 0;
rpc_wake_up_task(task);
-out_unlock:
spin_unlock(&xprt->sock_lock);
}
@@ -1220,16 +1197,17 @@ xprt_transmit(struct rpc_task *task)
return;
out_receive:
dprintk("RPC: %4d xmit complete\n", task->tk_pid);
+ spin_lock_bh(&xprt->sock_lock);
/* Set the task's receive timeout value */
if (!xprt->nocong) {
task->tk_timeout = rpc_calc_rto(&clnt->cl_rtt,
task->tk_msg.rpc_proc->p_timer);
- req->rq_ntimeo = 0;
+ task->tk_timeout <<= clnt->cl_timeout.to_retries
+ - req->rq_timeout.to_retries;
if (task->tk_timeout > req->rq_timeout.to_maxval)
task->tk_timeout = req->rq_timeout.to_maxval;
} else
task->tk_timeout = req->rq_timeout.to_current;
- spin_lock_bh(&xprt->sock_lock);
/* Don't race with disconnect */
if (!xprt_connected(xprt))
task->tk_status = -ENOTCONN;
_