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authorChuck Lever <cel@netapp.com>2005-08-25 19:25:52 -0400
committerTrond Myklebust <Trond.Myklebust@netapp.com>2005-09-23 12:38:41 -0400
commit46c0ee8bc4ad3743de05e8b8b20201df44dcb6d3 (patch)
tree6b2993ff1cefb69cc3cc40c3605d088ea2af3c98 /net/sunrpc/xprt.c
parent49e9a89086b3cae784a4868ca852863e4f4ea3fe (diff)
[PATCH] RPC: separate xprt_timer implementations
Allow transports to hook the retransmit timer interrupt. Some transports calculate their congestion window here so that a retransmit timeout has immediate effect on the congestion window. Test-plan: Use WAN simulation to cause sporadic bursty packet loss. Look for significant regression in performance or client stability. Signed-off-by: Chuck Lever <cel@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'net/sunrpc/xprt.c')
-rw-r--r--net/sunrpc/xprt.c45
1 files changed, 20 insertions, 25 deletions
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index e92ea99dd318..ffc595592af3 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -289,16 +289,19 @@ __xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req)
289 __xprt_lock_write_next_cong(xprt); 289 __xprt_lock_write_next_cong(xprt);
290} 290}
291 291
292/* 292/**
293 * Adjust RPC congestion window 293 * xprt_adjust_cwnd - adjust transport congestion window
294 * @task: recently completed RPC request used to adjust window
295 * @result: result code of completed RPC request
296 *
294 * We use a time-smoothed congestion estimator to avoid heavy oscillation. 297 * We use a time-smoothed congestion estimator to avoid heavy oscillation.
295 */ 298 */
296static void 299void xprt_adjust_cwnd(struct rpc_task *task, int result)
297xprt_adjust_cwnd(struct rpc_xprt *xprt, int result)
298{ 300{
299 unsigned long cwnd; 301 struct rpc_rqst *req = task->tk_rqstp;
302 struct rpc_xprt *xprt = task->tk_xprt;
303 unsigned long cwnd = xprt->cwnd;
300 304
301 cwnd = xprt->cwnd;
302 if (result >= 0 && cwnd <= xprt->cong) { 305 if (result >= 0 && cwnd <= xprt->cong) {
303 /* The (cwnd >> 1) term makes sure 306 /* The (cwnd >> 1) term makes sure
304 * the result gets rounded properly. */ 307 * the result gets rounded properly. */
@@ -314,6 +317,7 @@ xprt_adjust_cwnd(struct rpc_xprt *xprt, int result)
314 dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n", 317 dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n",
315 xprt->cong, xprt->cwnd, cwnd); 318 xprt->cong, xprt->cwnd, cwnd);
316 xprt->cwnd = cwnd; 319 xprt->cwnd = cwnd;
320 __xprt_put_cong(xprt, req);
317} 321}
318 322
319/** 323/**
@@ -602,8 +606,7 @@ void xprt_complete_rqst(struct rpc_xprt *xprt, struct rpc_rqst *req, int copied)
602 /* Adjust congestion window */ 606 /* Adjust congestion window */
603 if (!xprt->nocong) { 607 if (!xprt->nocong) {
604 unsigned timer = task->tk_msg.rpc_proc->p_timer; 608 unsigned timer = task->tk_msg.rpc_proc->p_timer;
605 xprt_adjust_cwnd(xprt, copied); 609 xprt_adjust_cwnd(task, copied);
606 __xprt_put_cong(xprt, req);
607 if (timer) { 610 if (timer) {
608 if (req->rq_ntrans == 1) 611 if (req->rq_ntrans == 1)
609 rpc_update_rtt(clnt->cl_rtt, timer, 612 rpc_update_rtt(clnt->cl_rtt, timer,
@@ -640,27 +643,19 @@ void xprt_complete_rqst(struct rpc_xprt *xprt, struct rpc_rqst *req, int copied)
640 return; 643 return;
641} 644}
642 645
643/* 646static void xprt_timer(struct rpc_task *task)
644 * RPC receive timeout handler.
645 */
646static void
647xprt_timer(struct rpc_task *task)
648{ 647{
649 struct rpc_rqst *req = task->tk_rqstp; 648 struct rpc_rqst *req = task->tk_rqstp;
650 struct rpc_xprt *xprt = req->rq_xprt; 649 struct rpc_xprt *xprt = req->rq_xprt;
651 650
652 spin_lock(&xprt->transport_lock); 651 dprintk("RPC: %4d xprt_timer\n", task->tk_pid);
653 if (req->rq_received)
654 goto out;
655
656 xprt_adjust_cwnd(req->rq_xprt, -ETIMEDOUT);
657 __xprt_put_cong(xprt, req);
658 652
659 dprintk("RPC: %4d xprt_timer (%s request)\n", 653 spin_lock(&xprt->transport_lock);
660 task->tk_pid, req ? "pending" : "backlogged"); 654 if (!req->rq_received) {
661 655 if (xprt->ops->timer)
662 task->tk_status = -ETIMEDOUT; 656 xprt->ops->timer(task);
663out: 657 task->tk_status = -ETIMEDOUT;
658 }
664 task->tk_timeout = 0; 659 task->tk_timeout = 0;
665 rpc_wake_up_task(task); 660 rpc_wake_up_task(task);
666 spin_unlock(&xprt->transport_lock); 661 spin_unlock(&xprt->transport_lock);