From: Trond Myklebust <trondmy@gmail.com>
To: linux-nfs@vger.kernel.org
Subject: [PATCH v3 15/44] SUNRPC: Refactor xprt_transmit() to remove the reply queue code
Date: Mon, 17 Sep 2018 09:03:06 -0400 [thread overview]
Message-ID: <20180917130335.112832-16-trond.myklebust@hammerspace.com> (raw)
In-Reply-To: <20180917130335.112832-15-trond.myklebust@hammerspace.com>
Separate out the action of adding a request to the reply queue so that the
backchannel code can simply skip calling it altogether.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
include/linux/sunrpc/xprt.h | 1 +
net/sunrpc/backchannel_rqst.c | 1 -
net/sunrpc/clnt.c | 5 ++
net/sunrpc/xprt.c | 126 +++++++++++++++++++-----------
net/sunrpc/xprtrdma/backchannel.c | 1 -
5 files changed, 88 insertions(+), 46 deletions(-)
diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index c25d0a5fda69..0250294c904a 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -334,6 +334,7 @@ void xprt_free_slot(struct rpc_xprt *xprt,
struct rpc_rqst *req);
void xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
bool xprt_prepare_transmit(struct rpc_task *task);
+void xprt_request_enqueue_receive(struct rpc_task *task);
void xprt_transmit(struct rpc_task *task);
void xprt_end_transmit(struct rpc_task *task);
int xprt_adjust_timeout(struct rpc_rqst *req);
diff --git a/net/sunrpc/backchannel_rqst.c b/net/sunrpc/backchannel_rqst.c
index 3c15a99b9700..fa5ba6ed3197 100644
--- a/net/sunrpc/backchannel_rqst.c
+++ b/net/sunrpc/backchannel_rqst.c
@@ -91,7 +91,6 @@ struct rpc_rqst *xprt_alloc_bc_req(struct rpc_xprt *xprt, gfp_t gfp_flags)
return NULL;
req->rq_xprt = xprt;
- INIT_LIST_HEAD(&req->rq_list);
INIT_LIST_HEAD(&req->rq_bc_list);
/* Preallocate one XDR receive buffer */
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index a858366cd15d..414966273a3f 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1962,6 +1962,11 @@ call_transmit(struct rpc_task *task)
return;
}
}
+
+ /* Add task to reply queue before transmission to avoid races */
+ if (rpc_reply_expected(task))
+ xprt_request_enqueue_receive(task);
+
if (!xprt_prepare_transmit(task))
return;
task->tk_action = call_transmit_status;
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 6e3d4b4ee79e..d8f870b5dd46 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -888,6 +888,61 @@ static void xprt_wait_on_pinned_rqst(struct rpc_rqst *req)
wait_var_event(&req->rq_pin, !xprt_is_pinned_rqst(req));
}
+static bool
+xprt_request_data_received(struct rpc_task *task)
+{
+ return !test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate) &&
+ READ_ONCE(task->tk_rqstp->rq_reply_bytes_recvd) != 0;
+}
+
+static bool
+xprt_request_need_enqueue_receive(struct rpc_task *task, struct rpc_rqst *req)
+{
+ return !xprt_request_data_received(task);
+}
+
+/**
+ * xprt_request_enqueue_receive - Add an request to the receive queue
+ * @task: RPC task
+ *
+ */
+void
+xprt_request_enqueue_receive(struct rpc_task *task)
+{
+ struct rpc_rqst *req = task->tk_rqstp;
+ struct rpc_xprt *xprt = req->rq_xprt;
+
+ if (!xprt_request_need_enqueue_receive(task, req))
+ return;
+ spin_lock(&xprt->queue_lock);
+
+ /* Update the softirq receive buffer */
+ memcpy(&req->rq_private_buf, &req->rq_rcv_buf,
+ sizeof(req->rq_private_buf));
+
+ /* Add request to the receive list */
+ list_add_tail(&req->rq_list, &xprt->recv);
+ set_bit(RPC_TASK_NEED_RECV, &task->tk_runstate);
+ spin_unlock(&xprt->queue_lock);
+
+ xprt_reset_majortimeo(req);
+ /* Turn off autodisconnect */
+ del_singleshot_timer_sync(&xprt->timer);
+}
+
+/**
+ * xprt_request_dequeue_receive_locked - Remove a request from the receive queue
+ * @task: RPC task
+ *
+ * Caller must hold xprt->queue_lock.
+ */
+static void
+xprt_request_dequeue_receive_locked(struct rpc_task *task)
+{
+ if (test_and_clear_bit(RPC_TASK_NEED_RECV, &task->tk_runstate))
+ list_del(&task->tk_rqstp->rq_list);
+}
+
/**
* xprt_update_rtt - Update RPC RTT statistics
* @task: RPC request that recently completed
@@ -927,24 +982,16 @@ void xprt_complete_rqst(struct rpc_task *task, int copied)
xprt->stat.recvs++;
- list_del_init(&req->rq_list);
req->rq_private_buf.len = copied;
/* Ensure all writes are done before we update */
/* req->rq_reply_bytes_recvd */
smp_wmb();
req->rq_reply_bytes_recvd = copied;
- clear_bit(RPC_TASK_NEED_RECV, &task->tk_runstate);
+ xprt_request_dequeue_receive_locked(task);
rpc_wake_up_queued_task(&xprt->pending, task);
}
EXPORT_SYMBOL_GPL(xprt_complete_rqst);
-static bool
-xprt_request_data_received(struct rpc_task *task)
-{
- return !test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate) &&
- task->tk_rqstp->rq_reply_bytes_recvd != 0;
-}
-
static void xprt_timer(struct rpc_task *task)
{
struct rpc_rqst *req = task->tk_rqstp;
@@ -1018,32 +1065,15 @@ void xprt_transmit(struct rpc_task *task)
dprintk("RPC: %5u xprt_transmit(%u)\n", task->tk_pid, req->rq_slen);
- if (!req->rq_reply_bytes_recvd) {
-
+ if (!req->rq_bytes_sent) {
+ if (xprt_request_data_received(task))
+ return;
/* Verify that our message lies in the RPCSEC_GSS window */
- if (!req->rq_bytes_sent && rpcauth_xmit_need_reencode(task)) {
+ if (rpcauth_xmit_need_reencode(task)) {
task->tk_status = -EBADMSG;
return;
}
-
- if (list_empty(&req->rq_list) && rpc_reply_expected(task)) {
- /*
- * Add to the list only if we're expecting a reply
- */
- /* Update the softirq receive buffer */
- memcpy(&req->rq_private_buf, &req->rq_rcv_buf,
- sizeof(req->rq_private_buf));
- /* Add request to the receive list */
- spin_lock(&xprt->queue_lock);
- list_add_tail(&req->rq_list, &xprt->recv);
- set_bit(RPC_TASK_NEED_RECV, &task->tk_runstate);
- spin_unlock(&xprt->queue_lock);
- xprt_reset_majortimeo(req);
- /* Turn off autodisconnect */
- del_singleshot_timer_sync(&xprt->timer);
- }
- } else if (xprt_request_data_received(task) && !req->rq_bytes_sent)
- return;
+ }
connect_cookie = xprt->connect_cookie;
status = xprt->ops->send_request(task);
@@ -1285,7 +1315,6 @@ xprt_request_init(struct rpc_task *task)
struct rpc_xprt *xprt = task->tk_xprt;
struct rpc_rqst *req = task->tk_rqstp;
- INIT_LIST_HEAD(&req->rq_list);
req->rq_timeout = task->tk_client->cl_timeout->to_initval;
req->rq_task = task;
req->rq_xprt = xprt;
@@ -1355,6 +1384,26 @@ void xprt_retry_reserve(struct rpc_task *task)
xprt_do_reserve(xprt, task);
}
+static void
+xprt_request_dequeue_all(struct rpc_task *task, struct rpc_rqst *req)
+{
+ struct rpc_xprt *xprt = req->rq_xprt;
+
+ if (test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate) ||
+ xprt_is_pinned_rqst(req)) {
+ spin_lock(&xprt->queue_lock);
+ xprt_request_dequeue_receive_locked(task);
+ while (xprt_is_pinned_rqst(req)) {
+ set_bit(RPC_TASK_MSG_PIN_WAIT, &task->tk_runstate);
+ spin_unlock(&xprt->queue_lock);
+ xprt_wait_on_pinned_rqst(req);
+ spin_lock(&xprt->queue_lock);
+ clear_bit(RPC_TASK_MSG_PIN_WAIT, &task->tk_runstate);
+ }
+ spin_unlock(&xprt->queue_lock);
+ }
+}
+
/**
* xprt_release - release an RPC request slot
* @task: task which is finished with the slot
@@ -1379,18 +1428,7 @@ void xprt_release(struct rpc_task *task)
task->tk_ops->rpc_count_stats(task, task->tk_calldata);
else if (task->tk_client)
rpc_count_iostats(task, task->tk_client->cl_metrics);
- spin_lock(&xprt->queue_lock);
- if (!list_empty(&req->rq_list)) {
- list_del_init(&req->rq_list);
- if (xprt_is_pinned_rqst(req)) {
- set_bit(RPC_TASK_MSG_PIN_WAIT, &req->rq_task->tk_runstate);
- spin_unlock(&xprt->queue_lock);
- xprt_wait_on_pinned_rqst(req);
- spin_lock(&xprt->queue_lock);
- clear_bit(RPC_TASK_MSG_PIN_WAIT, &req->rq_task->tk_runstate);
- }
- }
- spin_unlock(&xprt->queue_lock);
+ xprt_request_dequeue_all(task, req);
spin_lock_bh(&xprt->transport_lock);
xprt->ops->release_xprt(xprt, task);
if (xprt->ops->release_request)
diff --git a/net/sunrpc/xprtrdma/backchannel.c b/net/sunrpc/xprtrdma/backchannel.c
index 90adeff4c06b..ed58761e6b23 100644
--- a/net/sunrpc/xprtrdma/backchannel.c
+++ b/net/sunrpc/xprtrdma/backchannel.c
@@ -51,7 +51,6 @@ static int rpcrdma_bc_setup_reqs(struct rpcrdma_xprt *r_xprt,
rqst = &req->rl_slot;
rqst->rq_xprt = xprt;
- INIT_LIST_HEAD(&rqst->rq_list);
INIT_LIST_HEAD(&rqst->rq_bc_list);
__set_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state);
spin_lock_bh(&xprt->bc_pa_lock);
--
2.17.1
next prev parent reply other threads:[~2018-09-17 18:31 UTC|newest]
Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-17 13:02 [PATCH v3 00/44] Convert RPC client transmission to a queued model Trond Myklebust
2018-09-17 13:02 ` [PATCH v3 01/44] SUNRPC: Clean up initialisation of the struct rpc_rqst Trond Myklebust
2018-09-17 13:02 ` [PATCH v3 02/44] SUNRPC: If there is no reply expected, bail early from call_decode Trond Myklebust
2018-09-17 13:02 ` [PATCH v3 03/44] SUNRPC: The transmitted message must lie in the RPCSEC window of validity Trond Myklebust
2018-09-17 13:02 ` [PATCH v3 04/44] SUNRPC: Simplify identification of when the message send/receive is complete Trond Myklebust
2018-09-17 13:02 ` [PATCH v3 05/44] SUNRPC: Avoid holding locks across the XDR encoding of the RPC message Trond Myklebust
2018-09-17 13:02 ` [PATCH v3 06/44] SUNRPC: Rename TCP receive-specific state variables Trond Myklebust
2018-09-17 13:02 ` [PATCH v3 07/44] SUNRPC: Move reset of TCP state variables into the reconnect code Trond Myklebust
2018-09-17 13:02 ` [PATCH v3 08/44] SUNRPC: Add socket transmit queue offset tracking Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 09/44] SUNRPC: Simplify dealing with aborted partially transmitted messages Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 10/44] SUNRPC: Refactor the transport request pinning Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 11/44] SUNRPC: Add a helper to wake up a sleeping rpc_task and set its status Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 12/44] SUNRPC: Test whether the task is queued before grabbing the queue spinlocks Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 13/44] SUNRPC: Don't wake queued RPC calls multiple times in xprt_transmit Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 14/44] SUNRPC: Rename xprt->recv_lock to xprt->queue_lock Trond Myklebust
2018-09-17 13:03 ` Trond Myklebust [this message]
2018-09-17 13:03 ` [PATCH v3 16/44] SUNRPC: Refactor xprt_transmit() to remove wait for reply code Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 17/44] SUNRPC: Minor cleanup for call_transmit() Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 18/44] SUNRPC: Distinguish between the slot allocation list and receive queue Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 19/44] SUNRPC: Add a transmission queue for RPC requests Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 20/44] SUNRPC: Refactor RPC call encoding Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 21/44] SUNRPC: Fix up the back channel transmit Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 22/44] SUNRPC: Treat the task and request as separate in the xprt_ops->send_request() Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 23/44] SUNRPC: Don't reset the request 'bytes_sent' counter when releasing XPRT_LOCK Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 24/44] SUNRPC: Simplify xprt_prepare_transmit() Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 25/44] SUNRPC: Move RPC retransmission stat counter to xprt_transmit() Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 26/44] SUNRPC: Improve latency for interactive tasks Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 27/44] SUNRPC: Support for congestion control when queuing is enabled Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 28/44] SUNRPC: Enqueue swapper tagged RPCs at the head of the transmit queue Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 29/44] SUNRPC: Allow calls to xprt_transmit() to drain the entire " Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 30/44] SUNRPC: Allow soft RPC calls to time out when waiting for the XPRT_LOCK Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 31/44] SUNRPC: Turn off throttling of RPC slots for TCP sockets Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 32/44] SUNRPC: Clean up transport write space handling Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 33/44] SUNRPC: Cleanup: remove the unused 'task' argument from the request_send() Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 34/44] SUNRPC: Don't take transport->lock unnecessarily when taking XPRT_LOCK Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 35/44] SUNRPC: Convert xprt receive queue to use an rbtree Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 36/44] SUNRPC: Fix priority queue fairness Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 37/44] SUNRPC: Convert the xprt->sending queue back to an ordinary wait queue Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 38/44] SUNRPC: Add a label for RPC calls that require allocation on receive Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 39/44] SUNRPC: Add a bvec array to struct xdr_buf for use with iovec_iter() Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 40/44] SUNRPC: Simplify TCP receive code by switching to using iterators Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 41/44] SUNRPC: Clean up - rename xs_tcp_data_receive() to xs_stream_data_receive() Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 42/44] SUNRPC: Allow AF_LOCAL sockets to use the generic stream receive Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 43/44] SUNRPC: Clean up xs_udp_data_receive() Trond Myklebust
2018-09-17 13:03 ` [PATCH v3 44/44] SUNRPC: Unexport xdr_partial_copy_from_skb() Trond Myklebust
2018-09-17 20:44 ` [PATCH v3 40/44] SUNRPC: Simplify TCP receive code by switching to using iterators Trond Myklebust
2018-11-09 11:19 ` Catalin Marinas
2018-11-29 19:28 ` Cristian Marussi
2018-11-29 19:56 ` Trond Myklebust
2018-11-30 16:19 ` Cristian Marussi
2018-11-30 19:31 ` Trond Myklebust
2018-12-02 16:44 ` Trond Myklebust
2018-12-03 11:45 ` Catalin Marinas
2018-12-03 11:53 ` Cristian Marussi
2018-12-03 18:54 ` Cristian Marussi
2018-12-27 19:21 ` [PATCH v3 26/44] SUNRPC: Improve latency for interactive tasks Chuck Lever
2018-12-27 22:14 ` Trond Myklebust
2018-12-27 22:34 ` Chuck Lever
2018-12-31 18:09 ` Trond Myklebust
2018-12-31 18:44 ` Chuck Lever
2018-12-31 18:59 ` Trond Myklebust
2018-12-31 19:09 ` Chuck Lever
2018-12-31 19:18 ` Trond Myklebust
2018-12-31 19:21 ` Trond Myklebust
2019-01-02 18:17 ` Chuck Lever
2019-01-02 18:45 ` Trond Myklebust
2019-01-02 18:51 ` Chuck Lever
2019-01-02 18:57 ` Trond Myklebust
2019-01-02 19:06 ` Trond Myklebust
2019-01-02 19:24 ` Trond Myklebust
2019-01-02 19:33 ` Chuck Lever
2019-01-02 19:08 ` Chuck Lever
2019-01-02 19:11 ` Trond Myklebust
2018-09-18 21:01 ` [PATCH v3 15/44] SUNRPC: Refactor xprt_transmit() to remove the reply queue code Anna Schumaker
2018-09-19 15:48 ` Trond Myklebust
2018-09-19 17:30 ` Anna Schumaker
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180917130335.112832-16-trond.myklebust@hammerspace.com \
--to=trondmy@gmail.com \
--cc=linux-nfs@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).