diff options
| -rw-r--r-- | include/linux/sunrpc/xprt.h | 2 | ||||
| -rw-r--r-- | net/sunrpc/clnt.c | 17 | ||||
| -rw-r--r-- | net/sunrpc/xprt.c | 61 |
3 files changed, 76 insertions, 4 deletions
diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h index 30834be..12815f6 100644 --- a/include/linux/sunrpc/xprt.h +++ b/include/linux/sunrpc/xprt.h @@ -279,6 +279,7 @@ struct xprt_class { struct rpc_xprt *xprt_create_transport(struct xprt_create *args); void xprt_connect(struct rpc_task *task); void xprt_reserve(struct rpc_task *task); +void xprt_retry_reserve(struct rpc_task *task); int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task); int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task); void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task); @@ -334,6 +335,7 @@ int xs_swapper(struct rpc_xprt *xprt, int enable); #define XPRT_CLOSING (6) #define XPRT_CONNECTION_ABORT (7) #define XPRT_CONNECTION_CLOSE (8) +#define XPRT_CONGESTED (9) static inline void xprt_set_connected(struct rpc_xprt *xprt) { diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index b95a0a2..a80ee9b 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -1306,6 +1306,8 @@ call_reserve(struct rpc_task *task) xprt_reserve(task); } +static void call_retry_reserve(struct rpc_task *task); + /* * 1b. Grok the result of xprt_reserve() */ @@ -1347,7 +1349,7 @@ call_reserveresult(struct rpc_task *task) case -ENOMEM: rpc_delay(task, HZ >> 2); case -EAGAIN: /* woken up; retry */ - task->tk_action = call_reserve; + task->tk_action = call_retry_reserve; return; case -EIO: /* probably a shutdown */ break; @@ -1360,6 +1362,19 @@ call_reserveresult(struct rpc_task *task) } /* + * 1c. Retry reserving an RPC call slot + */ +static void +call_retry_reserve(struct rpc_task *task) +{ + dprint_status(task); + + task->tk_status = 0; + task->tk_action = call_reserveresult; + xprt_retry_reserve(task); +} + +/* * 2. Bind and/or refresh the credentials */ static void diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index b7478d5..745fca3 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -948,6 +948,34 @@ void xprt_transmit(struct rpc_task *task) spin_unlock_bh(&xprt->transport_lock); } +static void xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task) +{ + set_bit(XPRT_CONGESTED, &xprt->state); + rpc_sleep_on(&xprt->backlog, task, NULL); +} + +static void xprt_wake_up_backlog(struct rpc_xprt *xprt) +{ + if (rpc_wake_up_next(&xprt->backlog) == NULL) + clear_bit(XPRT_CONGESTED, &xprt->state); +} + +static bool xprt_throttle_congested(struct rpc_xprt *xprt, struct rpc_task *task) +{ + bool ret = false; + + if (!test_bit(XPRT_CONGESTED, &xprt->state)) + goto out; + spin_lock(&xprt->reserve_lock); + if (test_bit(XPRT_CONGESTED, &xprt->state)) { + rpc_sleep_on(&xprt->backlog, task, NULL); + ret = true; + } + spin_unlock(&xprt->reserve_lock); +out: + return ret; +} + static struct rpc_rqst *xprt_dynamic_alloc_slot(struct rpc_xprt *xprt, gfp_t gfp_flags) { struct rpc_rqst *req = ERR_PTR(-EAGAIN); @@ -992,7 +1020,7 @@ void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task) task->tk_status = -ENOMEM; break; case -EAGAIN: - rpc_sleep_on(&xprt->backlog, task, NULL); + xprt_add_backlog(xprt, task); dprintk("RPC: waiting for request slot\n"); default: task->tk_status = -EAGAIN; @@ -1028,7 +1056,7 @@ static void xprt_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req) memset(req, 0, sizeof(*req)); /* mark unused */ list_add(&req->rq_list, &xprt->free); } - rpc_wake_up_next(&xprt->backlog); + xprt_wake_up_backlog(xprt); spin_unlock(&xprt->reserve_lock); } @@ -1092,7 +1120,8 @@ EXPORT_SYMBOL_GPL(xprt_free); * xprt_reserve - allocate an RPC request slot * @task: RPC task requesting a slot allocation * - * If no more slots are available, place the task on the transport's + * If the transport is marked as being congested, or if no more + * slots are available, place the task on the transport's * backlog queue. */ void xprt_reserve(struct rpc_task *task) @@ -1107,6 +1136,32 @@ void xprt_reserve(struct rpc_task *task) task->tk_status = -EAGAIN; rcu_read_lock(); xprt = rcu_dereference(task->tk_client->cl_xprt); + if (!xprt_throttle_congested(xprt, task)) + xprt->ops->alloc_slot(xprt, task); + rcu_read_unlock(); +} + +/** + * xprt_retry_reserve - allocate an RPC request slot + * @task: RPC task requesting a slot allocation + * + * If no more slots are available, place the task on the transport's + * backlog queue. + * Note that the only difference with xprt_reserve is that we now + * ignore the value of the XPRT_CONGESTED flag. + */ +void xprt_retry_reserve(struct rpc_task *task) +{ + struct rpc_xprt *xprt; + + task->tk_status = 0; + if (task->tk_rqstp != NULL) + return; + + task->tk_timeout = 0; + task->tk_status = -EAGAIN; + rcu_read_lock(); + xprt = rcu_dereference(task->tk_client->cl_xprt); xprt->ops->alloc_slot(xprt, task); rcu_read_unlock(); } |
