Blame view
net/rds/threads.c
6.93 KB
00e0f34c6 RDS: Connection h... |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 |
/* * Copyright (c) 2006 Oracle. All rights reserved. * * This software is available to you under a choice of one of two * licenses. You may choose to be licensed under the terms of the GNU * General Public License (GPL) Version 2, available from the file * COPYING in the main directory of this source tree, or the * OpenIB.org BSD license below: * * Redistribution and use in source and binary forms, with or * without modification, are permitted provided that the following * conditions are met: * * - Redistributions of source code must retain the above * copyright notice, this list of conditions and the following * disclaimer. * * - Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following * disclaimer in the documentation and/or other materials * provided with the distribution. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. * */ #include <linux/kernel.h> #include <linux/random.h> |
bc3b2d7fb net: Add export.h... |
35 |
#include <linux/export.h> |
00e0f34c6 RDS: Connection h... |
36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 |
#include "rds.h" /* * All of connection management is simplified by serializing it through * work queues that execute in a connection managing thread. * * TCP wants to send acks through sendpage() in response to data_ready(), * but it needs a process context to do so. * * The receive paths need to allocate but can't drop packets (!) so we have * a thread around to block allocating if the receive fast path sees an * allocation failure. */ /* Grand Unified Theory of connection life cycle: * At any point in time, the connection can be in one of these states: * DOWN, CONNECTING, UP, DISCONNECTING, ERROR * * The following transitions are possible: * ANY -> ERROR * UP -> DISCONNECTING * ERROR -> DISCONNECTING * DISCONNECTING -> DOWN * DOWN -> CONNECTING * CONNECTING -> UP * * Transition to state DISCONNECTING/DOWN: * - Inside the shutdown worker; synchronizes with xmit path |
0f4b1c7e8 rds: fix rds_send... |
65 |
* through RDS_IN_XMIT, and with connection management callbacks |
00e0f34c6 RDS: Connection h... |
66 67 68 69 70 71 |
* via c_cm_lock. * * For receive callbacks, we rely on the underlying transport * (TCP, IB/RDMA) to provide the necessary synchronisation. */ struct workqueue_struct *rds_wq; |
616b757ae RDS: Export symbo... |
72 |
EXPORT_SYMBOL_GPL(rds_wq); |
00e0f34c6 RDS: Connection h... |
73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 |
void rds_connect_complete(struct rds_connection *conn) { if (!rds_conn_transition(conn, RDS_CONN_CONNECTING, RDS_CONN_UP)) { printk(KERN_WARNING "%s: Cannot transition to state UP, " "current state is %d ", __func__, atomic_read(&conn->c_state)); atomic_set(&conn->c_state, RDS_CONN_ERROR); queue_work(rds_wq, &conn->c_down_w); return; } rdsdebug("conn %p for %pI4 to %pI4 complete ", conn, &conn->c_laddr, &conn->c_faddr); conn->c_reconnect_jiffies = 0; set_bit(0, &conn->c_map_queued); queue_delayed_work(rds_wq, &conn->c_send_w, 0); queue_delayed_work(rds_wq, &conn->c_recv_w, 0); } |
616b757ae RDS: Export symbo... |
96 |
EXPORT_SYMBOL_GPL(rds_connect_complete); |
00e0f34c6 RDS: Connection h... |
97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 |
/* * This random exponential backoff is relied on to eventually resolve racing * connects. * * If connect attempts race then both parties drop both connections and come * here to wait for a random amount of time before trying again. Eventually * the backoff range will be so much greater than the time it takes to * establish a connection that one of the pair will establish the connection * before the other's random delay fires. * * Connection attempts that arrive while a connection is already established * are also considered to be racing connects. This lets a connection from * a rebooted machine replace an existing stale connection before the transport * notices that the connection has failed. * * We should *always* start with a random backoff; otherwise a broken connection * will always take several iterations to be re-established. */ |
2dc393573 RDS: move rds_shu... |
116 |
void rds_queue_reconnect(struct rds_connection *conn) |
00e0f34c6 RDS: Connection h... |
117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 |
{ unsigned long rand; rdsdebug("conn %p for %pI4 to %pI4 reconnect jiffies %lu ", conn, &conn->c_laddr, &conn->c_faddr, conn->c_reconnect_jiffies); set_bit(RDS_RECONNECT_PENDING, &conn->c_flags); if (conn->c_reconnect_jiffies == 0) { conn->c_reconnect_jiffies = rds_sysctl_reconnect_min_jiffies; queue_delayed_work(rds_wq, &conn->c_conn_w, 0); return; } get_random_bytes(&rand, sizeof(rand)); rdsdebug("%lu delay %lu ceil conn %p for %pI4 -> %pI4 ", rand % conn->c_reconnect_jiffies, conn->c_reconnect_jiffies, conn, &conn->c_laddr, &conn->c_faddr); queue_delayed_work(rds_wq, &conn->c_conn_w, rand % conn->c_reconnect_jiffies); conn->c_reconnect_jiffies = min(conn->c_reconnect_jiffies * 2, rds_sysctl_reconnect_max_jiffies); } void rds_connect_worker(struct work_struct *work) { struct rds_connection *conn = container_of(work, struct rds_connection, c_conn_w.work); int ret; clear_bit(RDS_RECONNECT_PENDING, &conn->c_flags); if (rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING)) { ret = conn->c_trans->conn_connect(conn); rdsdebug("conn %p for %pI4 to %pI4 dispatched, ret %d ", conn, &conn->c_laddr, &conn->c_faddr, ret); if (ret) { if (rds_conn_transition(conn, RDS_CONN_CONNECTING, RDS_CONN_DOWN)) rds_queue_reconnect(conn); else rds_conn_error(conn, "RDS: connect failed "); } } } |
00e0f34c6 RDS: Connection h... |
165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 |
void rds_send_worker(struct work_struct *work) { struct rds_connection *conn = container_of(work, struct rds_connection, c_send_w.work); int ret; if (rds_conn_state(conn) == RDS_CONN_UP) { ret = rds_send_xmit(conn); rdsdebug("conn %p ret %d ", conn, ret); switch (ret) { case -EAGAIN: rds_stats_inc(s_send_immediate_retry); queue_delayed_work(rds_wq, &conn->c_send_w, 0); break; case -ENOMEM: rds_stats_inc(s_send_delayed_retry); queue_delayed_work(rds_wq, &conn->c_send_w, 2); default: break; } } } void rds_recv_worker(struct work_struct *work) { struct rds_connection *conn = container_of(work, struct rds_connection, c_recv_w.work); int ret; if (rds_conn_state(conn) == RDS_CONN_UP) { ret = conn->c_trans->recv(conn); rdsdebug("conn %p ret %d ", conn, ret); switch (ret) { case -EAGAIN: rds_stats_inc(s_recv_immediate_retry); queue_delayed_work(rds_wq, &conn->c_recv_w, 0); break; case -ENOMEM: rds_stats_inc(s_recv_delayed_retry); queue_delayed_work(rds_wq, &conn->c_recv_w, 2); default: break; } } } |
2dc393573 RDS: move rds_shu... |
210 211 212 213 214 215 |
void rds_shutdown_worker(struct work_struct *work) { struct rds_connection *conn = container_of(work, struct rds_connection, c_down_w); rds_conn_shutdown(conn); } |
00e0f34c6 RDS: Connection h... |
216 217 218 219 |
void rds_threads_exit(void) { destroy_workqueue(rds_wq); } |
ef87b7ea3 RDS: remove __ini... |
220 |
int rds_threads_init(void) |
00e0f34c6 RDS: Connection h... |
221 |
{ |
80c51be56 RDS: return to a ... |
222 |
rds_wq = create_singlethread_workqueue("krdsd"); |
8690bfa17 RDS: cleanup: rem... |
223 |
if (!rds_wq) |
00e0f34c6 RDS: Connection h... |
224 225 226 227 |
return -ENOMEM; return 0; } |