PerfectSwitch.cc revision 11035:690ecdba9324
1/* 2 * Copyright (c) 1999-2008 Mark D. Hill and David A. Wood 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29#include <algorithm> 30 31#include "base/cast.hh" 32#include "base/random.hh" 33#include "debug/RubyNetwork.hh" 34#include "mem/ruby/network/MessageBuffer.hh" 35#include "mem/ruby/network/simple/PerfectSwitch.hh" 36#include "mem/ruby/network/simple/SimpleNetwork.hh" 37#include "mem/ruby/network/simple/Switch.hh" 38#include "mem/ruby/slicc_interface/Message.hh" 39 40using namespace std; 41 42const int PRIORITY_SWITCH_LIMIT = 128; 43 44// Operator for helper class 45bool 46operator<(const LinkOrder& l1, const LinkOrder& l2) 47{ 48 return (l1.m_value < l2.m_value); 49} 50 51PerfectSwitch::PerfectSwitch(SwitchID sid, Switch *sw, uint32_t virt_nets) 52 : Consumer(sw) 53{ 54 m_switch_id = sid; 55 m_round_robin_start = 0; 56 m_wakeups_wo_switch = 0; 57 m_virtual_networks = virt_nets; 58} 59 60void 61PerfectSwitch::init(SimpleNetwork *network_ptr) 62{ 63 m_network_ptr = network_ptr; 64 65 for(int i = 0;i < m_virtual_networks;++i) { 66 m_pending_message_count.push_back(0); 67 } 68} 69 70void 71PerfectSwitch::addInPort(const vector<MessageBuffer*>& in) 72{ 73 NodeID port = m_in.size(); 74 m_in.push_back(in); 75 76 for (int i = 0; i < in.size(); ++i) { 77 if (in[i] != nullptr) { 78 in[i]->setConsumer(this); 79 in[i]->setIncomingLink(port); 80 in[i]->setVnet(i); 81 } 82 } 83} 84 85void 86PerfectSwitch::addOutPort(const vector<MessageBuffer*>& out, 87 const NetDest& routing_table_entry) 88{ 89 // Setup link order 90 LinkOrder l; 91 l.m_value = 0; 92 l.m_link = m_out.size(); 93 m_link_order.push_back(l); 94 95 // Add to routing table 96 m_out.push_back(out); 97 m_routing_table.push_back(routing_table_entry); 98} 99 100PerfectSwitch::~PerfectSwitch() 101{ 102} 103 104void 105PerfectSwitch::operateVnet(int vnet) 106{ 107 // This is for round-robin scheduling 108 int incoming = m_round_robin_start; 109 m_round_robin_start++; 110 if (m_round_robin_start >= m_in.size()) { 111 m_round_robin_start = 0; 112 } 113 114 if(m_pending_message_count[vnet] > 0) { 115 // for all input ports, use round robin scheduling 116 for (int counter = 0; counter < m_in.size(); counter++) { 117 // Round robin scheduling 118 incoming++; 119 if (incoming >= m_in.size()) { 120 incoming = 0; 121 } 122 123 // Is there a message waiting? 124 if (m_in[incoming].size() <= vnet) { 125 continue; 126 } 127 128 MessageBuffer *buffer = m_in[incoming][vnet]; 129 if (buffer == nullptr) { 130 continue; 131 } 132 133 operateMessageBuffer(buffer, incoming, vnet); 134 } 135 } 136} 137 138void 139PerfectSwitch::operateMessageBuffer(MessageBuffer *buffer, int incoming, 140 int vnet) 141{ 142 MsgPtr msg_ptr; 143 Message *net_msg_ptr = NULL; 144 145 // temporary vectors to store the routing results 146 vector<LinkID> output_links; 147 vector<NetDest> output_link_destinations; 148 149 while (buffer->isReady()) { 150 DPRINTF(RubyNetwork, "incoming: %d\n", incoming); 151 152 // Peek at message 153 msg_ptr = buffer->peekMsgPtr(); 154 net_msg_ptr = msg_ptr.get(); 155 DPRINTF(RubyNetwork, "Message: %s\n", (*net_msg_ptr)); 156 157 output_links.clear(); 158 output_link_destinations.clear(); 159 NetDest msg_dsts = net_msg_ptr->getDestination(); 160 161 // Unfortunately, the token-protocol sends some 162 // zero-destination messages, so this assert isn't valid 163 // assert(msg_dsts.count() > 0); 164 165 assert(m_link_order.size() == m_routing_table.size()); 166 assert(m_link_order.size() == m_out.size()); 167 168 if (m_network_ptr->getAdaptiveRouting()) { 169 if (m_network_ptr->isVNetOrdered(vnet)) { 170 // Don't adaptively route 171 for (int out = 0; out < m_out.size(); out++) { 172 m_link_order[out].m_link = out; 173 m_link_order[out].m_value = 0; 174 } 175 } else { 176 // Find how clogged each link is 177 for (int out = 0; out < m_out.size(); out++) { 178 int out_queue_length = 0; 179 for (int v = 0; v < m_virtual_networks; v++) { 180 out_queue_length += m_out[out][v]->getSize(); 181 } 182 int value = 183 (out_queue_length << 8) | 184 random_mt.random(0, 0xff); 185 m_link_order[out].m_link = out; 186 m_link_order[out].m_value = value; 187 } 188 189 // Look at the most empty link first 190 sort(m_link_order.begin(), m_link_order.end()); 191 } 192 } 193 194 for (int i = 0; i < m_routing_table.size(); i++) { 195 // pick the next link to look at 196 int link = m_link_order[i].m_link; 197 NetDest dst = m_routing_table[link]; 198 DPRINTF(RubyNetwork, "dst: %s\n", dst); 199 200 if (!msg_dsts.intersectionIsNotEmpty(dst)) 201 continue; 202 203 // Remember what link we're using 204 output_links.push_back(link); 205 206 // Need to remember which destinations need this message in 207 // another vector. This Set is the intersection of the 208 // routing_table entry and the current destination set. The 209 // intersection must not be empty, since we are inside "if" 210 output_link_destinations.push_back(msg_dsts.AND(dst)); 211 212 // Next, we update the msg_destination not to include 213 // those nodes that were already handled by this link 214 msg_dsts.removeNetDest(dst); 215 } 216 217 assert(msg_dsts.count() == 0); 218 219 // Check for resources - for all outgoing queues 220 bool enough = true; 221 for (int i = 0; i < output_links.size(); i++) { 222 int outgoing = output_links[i]; 223 224 if (!m_out[outgoing][vnet]->areNSlotsAvailable(1)) 225 enough = false; 226 227 DPRINTF(RubyNetwork, "Checking if node is blocked ..." 228 "outgoing: %d, vnet: %d, enough: %d\n", 229 outgoing, vnet, enough); 230 } 231 232 // There were not enough resources 233 if (!enough) { 234 scheduleEvent(Cycles(1)); 235 DPRINTF(RubyNetwork, "Can't deliver message since a node " 236 "is blocked\n"); 237 DPRINTF(RubyNetwork, "Message: %s\n", (*net_msg_ptr)); 238 break; // go to next incoming port 239 } 240 241 MsgPtr unmodified_msg_ptr; 242 243 if (output_links.size() > 1) { 244 // If we are sending this message down more than one link 245 // (size>1), we need to make a copy of the message so each 246 // branch can have a different internal destination we need 247 // to create an unmodified MsgPtr because the MessageBuffer 248 // enqueue func will modify the message 249 250 // This magic line creates a private copy of the message 251 unmodified_msg_ptr = msg_ptr->clone(); 252 } 253 254 // Dequeue msg 255 buffer->dequeue(); 256 m_pending_message_count[vnet]--; 257 258 // Enqueue it - for all outgoing queues 259 for (int i=0; i<output_links.size(); i++) { 260 int outgoing = output_links[i]; 261 262 if (i > 0) { 263 // create a private copy of the unmodified message 264 msg_ptr = unmodified_msg_ptr->clone(); 265 } 266 267 // Change the internal destination set of the message so it 268 // knows which destinations this link is responsible for. 269 net_msg_ptr = msg_ptr.get(); 270 net_msg_ptr->getDestination() = output_link_destinations[i]; 271 272 // Enqeue msg 273 DPRINTF(RubyNetwork, "Enqueuing net msg from " 274 "inport[%d][%d] to outport [%d][%d].\n", 275 incoming, vnet, outgoing, vnet); 276 277 m_out[outgoing][vnet]->enqueue(msg_ptr); 278 } 279 } 280} 281 282void 283PerfectSwitch::wakeup() 284{ 285 // Give the highest numbered link priority most of the time 286 m_wakeups_wo_switch++; 287 int highest_prio_vnet = m_virtual_networks-1; 288 int lowest_prio_vnet = 0; 289 int decrementer = 1; 290 291 // invert priorities to avoid starvation seen in the component network 292 if (m_wakeups_wo_switch > PRIORITY_SWITCH_LIMIT) { 293 m_wakeups_wo_switch = 0; 294 highest_prio_vnet = 0; 295 lowest_prio_vnet = m_virtual_networks-1; 296 decrementer = -1; 297 } 298 299 // For all components incoming queues 300 for (int vnet = highest_prio_vnet; 301 (vnet * decrementer) >= (decrementer * lowest_prio_vnet); 302 vnet -= decrementer) { 303 operateVnet(vnet); 304 } 305} 306 307void 308PerfectSwitch::storeEventInfo(int info) 309{ 310 m_pending_message_count[info]++; 311} 312 313void 314PerfectSwitch::clearStats() 315{ 316} 317void 318PerfectSwitch::collateStats() 319{ 320} 321 322 323void 324PerfectSwitch::print(std::ostream& out) const 325{ 326 out << "[PerfectSwitch " << m_switch_id << "]"; 327} 328