PerfectSwitch.cc revision 10895:287285860dd6
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 80 string desc = 81 csprintf("[Queue from port %s %s %s to PerfectSwitch]", 82 to_string(m_switch_id), to_string(port), 83 to_string(i)); 84 85 in[i]->setDescription(desc); 86 in[i]->setIncomingLink(port); 87 in[i]->setVnet(i); 88 } 89 } 90} 91 92void 93PerfectSwitch::addOutPort(const vector<MessageBuffer*>& out, 94 const NetDest& routing_table_entry) 95{ 96 // Setup link order 97 LinkOrder l; 98 l.m_value = 0; 99 l.m_link = m_out.size(); 100 m_link_order.push_back(l); 101 102 // Add to routing table 103 m_out.push_back(out); 104 m_routing_table.push_back(routing_table_entry); 105} 106 107PerfectSwitch::~PerfectSwitch() 108{ 109} 110 111void 112PerfectSwitch::operateVnet(int vnet) 113{ 114 MsgPtr msg_ptr; 115 Message *net_msg_ptr = NULL; 116 117 // This is for round-robin scheduling 118 int incoming = m_round_robin_start; 119 m_round_robin_start++; 120 if (m_round_robin_start >= m_in.size()) { 121 m_round_robin_start = 0; 122 } 123 124 if(m_pending_message_count[vnet] > 0) { 125 // for all input ports, use round robin scheduling 126 for (int counter = 0; counter < m_in.size(); counter++) { 127 // Round robin scheduling 128 incoming++; 129 if (incoming >= m_in.size()) { 130 incoming = 0; 131 } 132 133 // temporary vectors to store the routing results 134 vector<LinkID> output_links; 135 vector<NetDest> output_link_destinations; 136 137 // Is there a message waiting? 138 if (m_in[incoming].size() <= vnet) { 139 continue; 140 } 141 142 MessageBuffer *buffer = m_in[incoming][vnet]; 143 if (buffer == nullptr) { 144 continue; 145 } 146 147 while (buffer->isReady()) { 148 DPRINTF(RubyNetwork, "incoming: %d\n", incoming); 149 150 // Peek at message 151 msg_ptr = buffer->peekMsgPtr(); 152 net_msg_ptr = msg_ptr.get(); 153 DPRINTF(RubyNetwork, "Message: %s\n", (*net_msg_ptr)); 154 155 output_links.clear(); 156 output_link_destinations.clear(); 157 NetDest msg_dsts = net_msg_ptr->getDestination(); 158 159 // Unfortunately, the token-protocol sends some 160 // zero-destination messages, so this assert isn't valid 161 // assert(msg_dsts.count() > 0); 162 163 assert(m_link_order.size() == m_routing_table.size()); 164 assert(m_link_order.size() == m_out.size()); 165 166 if (m_network_ptr->getAdaptiveRouting()) { 167 if (m_network_ptr->isVNetOrdered(vnet)) { 168 // Don't adaptively route 169 for (int out = 0; out < m_out.size(); out++) { 170 m_link_order[out].m_link = out; 171 m_link_order[out].m_value = 0; 172 } 173 } else { 174 // Find how clogged each link is 175 for (int out = 0; out < m_out.size(); out++) { 176 int out_queue_length = 0; 177 for (int v = 0; v < m_virtual_networks; v++) { 178 out_queue_length += m_out[out][v]->getSize(); 179 } 180 int value = 181 (out_queue_length << 8) | 182 random_mt.random(0, 0xff); 183 m_link_order[out].m_link = out; 184 m_link_order[out].m_value = value; 185 } 186 187 // Look at the most empty link first 188 sort(m_link_order.begin(), m_link_order.end()); 189 } 190 } 191 192 for (int i = 0; i < m_routing_table.size(); i++) { 193 // pick the next link to look at 194 int link = m_link_order[i].m_link; 195 NetDest dst = m_routing_table[link]; 196 DPRINTF(RubyNetwork, "dst: %s\n", dst); 197 198 if (!msg_dsts.intersectionIsNotEmpty(dst)) 199 continue; 200 201 // Remember what link we're using 202 output_links.push_back(link); 203 204 // Need to remember which destinations need this message in 205 // another vector. This Set is the intersection of the 206 // routing_table entry and the current destination set. The 207 // intersection must not be empty, since we are inside "if" 208 output_link_destinations.push_back(msg_dsts.AND(dst)); 209 210 // Next, we update the msg_destination not to include 211 // those nodes that were already handled by this link 212 msg_dsts.removeNetDest(dst); 213 } 214 215 assert(msg_dsts.count() == 0); 216 217 // Check for resources - for all outgoing queues 218 bool enough = true; 219 for (int i = 0; i < output_links.size(); i++) { 220 int outgoing = output_links[i]; 221 222 if (!m_out[outgoing][vnet]->areNSlotsAvailable(1)) 223 enough = false; 224 225 DPRINTF(RubyNetwork, "Checking if node is blocked ..." 226 "outgoing: %d, vnet: %d, enough: %d\n", 227 outgoing, vnet, enough); 228 } 229 230 // There were not enough resources 231 if (!enough) { 232 scheduleEvent(Cycles(1)); 233 DPRINTF(RubyNetwork, "Can't deliver message since a node " 234 "is blocked\n"); 235 DPRINTF(RubyNetwork, "Message: %s\n", (*net_msg_ptr)); 236 break; // go to next incoming port 237 } 238 239 MsgPtr unmodified_msg_ptr; 240 241 if (output_links.size() > 1) { 242 // If we are sending this message down more than one link 243 // (size>1), we need to make a copy of the message so each 244 // branch can have a different internal destination we need 245 // to create an unmodified MsgPtr because the MessageBuffer 246 // enqueue func will modify the message 247 248 // This magic line creates a private copy of the message 249 unmodified_msg_ptr = msg_ptr->clone(); 250 } 251 252 // Dequeue msg 253 buffer->dequeue(); 254 m_pending_message_count[vnet]--; 255 256 // Enqueue it - for all outgoing queues 257 for (int i=0; i<output_links.size(); i++) { 258 int outgoing = output_links[i]; 259 260 if (i > 0) { 261 // create a private copy of the unmodified message 262 msg_ptr = unmodified_msg_ptr->clone(); 263 } 264 265 // Change the internal destination set of the message so it 266 // knows which destinations this link is responsible for. 267 net_msg_ptr = msg_ptr.get(); 268 net_msg_ptr->getDestination() = 269 output_link_destinations[i]; 270 271 // Enqeue msg 272 DPRINTF(RubyNetwork, "Enqueuing net msg from " 273 "inport[%d][%d] to outport [%d][%d].\n", 274 incoming, vnet, outgoing, vnet); 275 276 m_out[outgoing][vnet]->enqueue(msg_ptr); 277 } 278 } 279 } 280 } 281} 282 283void 284PerfectSwitch::wakeup() 285{ 286 // Give the highest numbered link priority most of the time 287 m_wakeups_wo_switch++; 288 int highest_prio_vnet = m_virtual_networks-1; 289 int lowest_prio_vnet = 0; 290 int decrementer = 1; 291 292 // invert priorities to avoid starvation seen in the component network 293 if (m_wakeups_wo_switch > PRIORITY_SWITCH_LIMIT) { 294 m_wakeups_wo_switch = 0; 295 highest_prio_vnet = 0; 296 lowest_prio_vnet = m_virtual_networks-1; 297 decrementer = -1; 298 } 299 300 // For all components incoming queues 301 for (int vnet = highest_prio_vnet; 302 (vnet * decrementer) >= (decrementer * lowest_prio_vnet); 303 vnet -= decrementer) { 304 operateVnet(vnet); 305 } 306} 307 308void 309PerfectSwitch::storeEventInfo(int info) 310{ 311 m_pending_message_count[info]++; 312} 313 314void 315PerfectSwitch::clearStats() 316{ 317} 318void 319PerfectSwitch::collateStats() 320{ 321} 322 323 324void 325PerfectSwitch::print(std::ostream& out) const 326{ 327 out << "[PerfectSwitch " << m_switch_id << "]"; 328} 329