From: Trond Myklebust <trondmy@gmail.com>
To: linux-nfs@vger.kernel.org
Subject: [PATCH v3 35/44] SUNRPC: Convert xprt receive queue to use an rbtree
Date: Mon, 17 Sep 2018 09:03:26 -0400 [thread overview]
Message-ID: <20180917130335.112832-36-trond.myklebust@hammerspace.com> (raw)
In-Reply-To: <20180917130335.112832-35-trond.myklebust@hammerspace.com>
If the server is slow, we can find ourselves with quite a lot of entries
on the receive queue. Converting the search from an O(n) to O(log(n))
can make a significant difference, particularly since we have to hold
a number of locks while searching.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
include/linux/sunrpc/xprt.h | 4 +-
net/sunrpc/xprt.c | 93 ++++++++++++++++++++++++++++++++-----
2 files changed, 84 insertions(+), 13 deletions(-)
diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 823860cce0bc..9be399020dab 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -85,7 +85,7 @@ struct rpc_rqst {
union {
struct list_head rq_list; /* Slot allocation list */
- struct list_head rq_recv; /* Receive queue */
+ struct rb_node rq_recv; /* Receive queue */
};
struct list_head rq_xmit; /* Send queue */
@@ -260,7 +260,7 @@ struct rpc_xprt {
* backchannel rpc_rqst's */
#endif /* CONFIG_SUNRPC_BACKCHANNEL */
- struct list_head recv_queue; /* Receive queue */
+ struct rb_root recv_queue; /* Receive queue */
struct {
unsigned long bind_count, /* total number of binds */
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index a1cb28a4adad..051638d5b39c 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -753,7 +753,7 @@ static void
xprt_schedule_autodisconnect(struct rpc_xprt *xprt)
__must_hold(&xprt->transport_lock)
{
- if (list_empty(&xprt->recv_queue) && xprt_has_timer(xprt))
+ if (RB_EMPTY_ROOT(&xprt->recv_queue) && xprt_has_timer(xprt))
mod_timer(&xprt->timer, xprt->last_used + xprt->idle_timeout);
}
@@ -763,7 +763,7 @@ xprt_init_autodisconnect(struct timer_list *t)
struct rpc_xprt *xprt = from_timer(xprt, t, timer);
spin_lock(&xprt->transport_lock);
- if (!list_empty(&xprt->recv_queue))
+ if (!RB_EMPTY_ROOT(&xprt->recv_queue))
goto out_abort;
/* Reset xprt->last_used to avoid connect/autodisconnect cycling */
xprt->last_used = jiffies;
@@ -880,6 +880,75 @@ static void xprt_connect_status(struct rpc_task *task)
}
}
+enum xprt_xid_rb_cmp {
+ XID_RB_EQUAL,
+ XID_RB_LEFT,
+ XID_RB_RIGHT,
+};
+static enum xprt_xid_rb_cmp
+xprt_xid_cmp(__be32 xid1, __be32 xid2)
+{
+ if (xid1 == xid2)
+ return XID_RB_EQUAL;
+ if ((__force u32)xid1 < (__force u32)xid2)
+ return XID_RB_LEFT;
+ return XID_RB_RIGHT;
+}
+
+static struct rpc_rqst *
+xprt_request_rb_find(struct rpc_xprt *xprt, __be32 xid)
+{
+ struct rb_node *n = xprt->recv_queue.rb_node;
+ struct rpc_rqst *req;
+
+ while (n != NULL) {
+ req = rb_entry(n, struct rpc_rqst, rq_recv);
+ switch (xprt_xid_cmp(xid, req->rq_xid)) {
+ case XID_RB_LEFT:
+ n = n->rb_left;
+ break;
+ case XID_RB_RIGHT:
+ n = n->rb_right;
+ break;
+ case XID_RB_EQUAL:
+ return req;
+ }
+ }
+ return NULL;
+}
+
+static void
+xprt_request_rb_insert(struct rpc_xprt *xprt, struct rpc_rqst *new)
+{
+ struct rb_node **p = &xprt->recv_queue.rb_node;
+ struct rb_node *n = NULL;
+ struct rpc_rqst *req;
+
+ while (*p != NULL) {
+ n = *p;
+ req = rb_entry(n, struct rpc_rqst, rq_recv);
+ switch(xprt_xid_cmp(new->rq_xid, req->rq_xid)) {
+ case XID_RB_LEFT:
+ p = &n->rb_left;
+ break;
+ case XID_RB_RIGHT:
+ p = &n->rb_right;
+ break;
+ case XID_RB_EQUAL:
+ WARN_ON_ONCE(new != req);
+ return;
+ }
+ }
+ rb_link_node(&new->rq_recv, n, p);
+ rb_insert_color(&new->rq_recv, &xprt->recv_queue);
+}
+
+static void
+xprt_request_rb_remove(struct rpc_xprt *xprt, struct rpc_rqst *req)
+{
+ rb_erase(&req->rq_recv, &xprt->recv_queue);
+}
+
/**
* xprt_lookup_rqst - find an RPC request corresponding to an XID
* @xprt: transport on which the original request was transmitted
@@ -891,12 +960,12 @@ struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid)
{
struct rpc_rqst *entry;
- list_for_each_entry(entry, &xprt->recv_queue, rq_recv)
- if (entry->rq_xid == xid) {
- trace_xprt_lookup_rqst(xprt, xid, 0);
- entry->rq_rtt = ktime_sub(ktime_get(), entry->rq_xtime);
- return entry;
- }
+ entry = xprt_request_rb_find(xprt, xid);
+ if (entry != NULL) {
+ trace_xprt_lookup_rqst(xprt, xid, 0);
+ entry->rq_rtt = ktime_sub(ktime_get(), entry->rq_xtime);
+ return entry;
+ }
dprintk("RPC: xprt_lookup_rqst did not find xid %08x\n",
ntohl(xid));
@@ -980,7 +1049,7 @@ xprt_request_enqueue_receive(struct rpc_task *task)
sizeof(req->rq_private_buf));
/* Add request to the receive list */
- list_add_tail(&req->rq_recv, &xprt->recv_queue);
+ xprt_request_rb_insert(xprt, req);
set_bit(RPC_TASK_NEED_RECV, &task->tk_runstate);
spin_unlock(&xprt->queue_lock);
@@ -998,8 +1067,10 @@ xprt_request_enqueue_receive(struct rpc_task *task)
static void
xprt_request_dequeue_receive_locked(struct rpc_task *task)
{
+ struct rpc_rqst *req = task->tk_rqstp;
+
if (test_and_clear_bit(RPC_TASK_NEED_RECV, &task->tk_runstate))
- list_del(&task->tk_rqstp->rq_recv);
+ xprt_request_rb_remove(req->rq_xprt, req);
}
/**
@@ -1710,7 +1781,7 @@ static void xprt_init(struct rpc_xprt *xprt, struct net *net)
spin_lock_init(&xprt->queue_lock);
INIT_LIST_HEAD(&xprt->free);
- INIT_LIST_HEAD(&xprt->recv_queue);
+ xprt->recv_queue = RB_ROOT;
INIT_LIST_HEAD(&xprt->xmit_queue);
#if defined(CONFIG_SUNRPC_BACKCHANNEL)
spin_lock_init(&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 ` [PATCH v3 15/44] SUNRPC: Refactor xprt_transmit() to remove the reply queue code Trond Myklebust
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 ` Trond Myklebust [this message]
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
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