src/mem/ruby/network/simple/Throttle.cc

   1
   2 /*
   3  * Copyright (c) 1999-2008 Mark D. Hill and David A. Wood
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions are
   8  * met: redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer;
  10  * redistributions in binary form must reproduce the above copyright
  11  * notice, this list of conditions and the following disclaimer in the
  12  * documentation and/or other materials provided with the distribution;
  13  * neither the name of the copyright holders nor the names of its
  14  * contributors may be used to endorse or promote products derived from
  15  * this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  18  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  19  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  20  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  21  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  22  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  23  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  27  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 /*
  31  * $Id$
  32  *
  33  * Description: see Throttle.hh
  34  *
  35  */
  36
  37 #include "mem/ruby/network/simple/Throttle.hh"
  38 #include "mem/ruby/buffers/MessageBuffer.hh"
  39 #include "mem/ruby/network/Network.hh"
  40 #include "mem/ruby/system/System.hh"
  41 #include "mem/ruby/slicc_interface/NetworkMessage.hh"
  42 #include "mem/protocol/Protocol.hh"
  43
  44 const int HIGH_RANGE = 256;
  45 const int ADJUST_INTERVAL = 50000;
  46 const int MESSAGE_SIZE_MULTIPLIER = 1000;
  47 //const int BROADCAST_SCALING = 4; // Have a 16p system act like a 64p systems
  48 const int BROADCAST_SCALING = 1;
  49 const int PRIORITY_SWITCH_LIMIT = 128;
  50
  51 static int network_message_to_size(NetworkMessage* net_msg_ptr);
  52
  53 extern std::ostream * debug_cout_ptr;
  54
  55 Throttle::Throttle(int sID, NodeID node, int link_latency, int link_bandwidth_multiplier)
  56 {
  57   init(node, link_latency, link_bandwidth_multiplier);
  58   m_sID = sID;
  59 }
  60
  61 Throttle::Throttle(NodeID node, int link_latency, int link_bandwidth_multiplier)
  62 {
  63   init(node, link_latency, link_bandwidth_multiplier);
  64   m_sID = 0;
  65 }
  66
  67 void Throttle::init(NodeID node, int link_latency, int link_bandwidth_multiplier)
  68 {
  69   m_node = node;
  70   m_vnets = 0;
  71
  72   ASSERT(link_bandwidth_multiplier > 0);
  73   m_link_bandwidth_multiplier = link_bandwidth_multiplier;
  74   m_link_latency = link_latency;
  75
  76   m_bash_counter = HIGH_RANGE;
  77   m_bandwidth_since_sample = 0;
  78   m_last_bandwidth_sample = 0;
  79   m_wakeups_wo_switch = 0;
  80   clearStats();
  81 }
  82
  83 void Throttle::clear()
  84 {
  85   for (int counter = 0; counter < m_vnets; counter++) {
  86     m_in[counter]->clear();
  87     m_out[counter]->clear();
  88   }
  89 }
  90
  91 void Throttle::addLinks(const Vector<MessageBuffer*>& in_vec, const Vector<MessageBuffer*>& out_vec)
  92 {
  93   assert(in_vec.size() == out_vec.size());
  94   for (int i=0; i<in_vec.size(); i++) {
  95     addVirtualNetwork(in_vec[i], out_vec[i]);
  96   }
  97
  98   m_message_counters.setSize(MessageSizeType_NUM);
  99   for (int i=0; i<MessageSizeType_NUM; i++) {
 100     m_message_counters[i].setSize(in_vec.size());
 101     for (int j=0; j<m_message_counters[i].size(); j++) {
 102       m_message_counters[i][j] = 0;
 103     }
 104   }
 105
 106   m_out_link_vec.insertAtBottom(out_vec);
 107 }
 108
 109 void Throttle::addVirtualNetwork(MessageBuffer* in_ptr, MessageBuffer* out_ptr)
 110 {
 111   m_units_remaining.insertAtBottom(0);
 112   m_in.insertAtBottom(in_ptr);
 113   m_out.insertAtBottom(out_ptr);
 114
 115   // Set consumer and description
 116   m_in[m_vnets]->setConsumer(this);
 117   string desc = "[Queue to Throttle " + NodeIDToString(m_sID) + " " + NodeIDToString(m_node) + "]";
 118   m_in[m_vnets]->setDescription(desc);
 119   m_vnets++;
 120 }
 121
 122 void Throttle::wakeup()
 123 {
 124   // Limits the number of message sent to a limited number of bytes/cycle.
 125   assert(getLinkBandwidth() > 0);
 126   int bw_remaining = getLinkBandwidth();
 127
 128   // Give the highest numbered link priority most of the time
 129   m_wakeups_wo_switch++;
 130   int highest_prio_vnet = m_vnets-1;
 131   int lowest_prio_vnet = 0;
 132   int counter = 1;
 133   bool schedule_wakeup = false;
 134
 135   // invert priorities to avoid starvation seen in the component network
 136   if (m_wakeups_wo_switch > PRIORITY_SWITCH_LIMIT) {
 137     m_wakeups_wo_switch = 0;
 138     highest_prio_vnet = 0;
 139     lowest_prio_vnet = m_vnets-1;
 140     counter = -1;
 141   }
 142
 143   for (int vnet = highest_prio_vnet; (vnet*counter) >= (counter*lowest_prio_vnet); vnet -= counter) {
 144
 145     assert(m_out[vnet] != NULL);
 146     assert(m_in[vnet] != NULL);
 147     assert(m_units_remaining[vnet] >= 0);
 148
 149     while ((bw_remaining > 0) && ((m_in[vnet]->isReady()) || (m_units_remaining[vnet] > 0)) && m_out[vnet]->areNSlotsAvailable(1)) {
 150
 151       // See if we are done transferring the previous message on this virtual network
 152       if (m_units_remaining[vnet] == 0 && m_in[vnet]->isReady()) {
 153
 154         // Find the size of the message we are moving
 155         MsgPtr msg_ptr = m_in[vnet]->peekMsgPtr();
 156         NetworkMessage* net_msg_ptr = dynamic_cast<NetworkMessage*>(msg_ptr.ref());
 157         m_units_remaining[vnet] += network_message_to_size(net_msg_ptr);
 158
 159         DEBUG_NEWLINE(NETWORK_COMP,HighPrio);
 160         DEBUG_MSG(NETWORK_COMP,HighPrio,"throttle: " + int_to_string(m_node)
 161                   + " my bw " + int_to_string(getLinkBandwidth())
 162                   + " bw spent enqueueing net msg " + int_to_string(m_units_remaining[vnet])
 163                   + " time: " + int_to_string(g_eventQueue_ptr->getTime()) + ".");
 164
 165         // Move the message
 166         m_out[vnet]->enqueue(m_in[vnet]->peekMsgPtr(), m_link_latency);
 167         m_in[vnet]->pop();
 168
 169         // Count the message
 170         m_message_counters[net_msg_ptr->getMessageSize()][vnet]++;
 171
 172         DEBUG_MSG(NETWORK_COMP,LowPrio,*m_out[vnet]);
 173         DEBUG_NEWLINE(NETWORK_COMP,HighPrio);
 174       }
 175
 176       // Calculate the amount of bandwidth we spent on this message
 177       int diff = m_units_remaining[vnet] - bw_remaining;
 178       m_units_remaining[vnet] = max(0, diff);
 179       bw_remaining = max(0, -diff);
 180     }
 181
 182     if ((bw_remaining > 0) && ((m_in[vnet]->isReady()) || (m_units_remaining[vnet] > 0)) && !m_out[vnet]->areNSlotsAvailable(1)) {
 183       DEBUG_MSG(NETWORK_COMP,LowPrio,vnet);
 184       schedule_wakeup = true; // schedule me to wakeup again because I'm waiting for my output queue to become available
 185     }
 186   }
 187
 188   // We should only wake up when we use the bandwidth
 189   //  assert(bw_remaining != getLinkBandwidth());  // This is only mostly true
 190
 191   // Record that we used some or all of the link bandwidth this cycle
 192   double ratio = 1.0-(double(bw_remaining)/double(getLinkBandwidth()));
 193   // If ratio = 0, we used no bandwidth, if ratio = 1, we used all
 194   linkUtilized(ratio);
 195
 196   // Sample the link bandwidth utilization over a number of cycles
 197   int bw_used = getLinkBandwidth()-bw_remaining;
 198   m_bandwidth_since_sample += bw_used;
 199
 200   // FIXME - comment out the bash specific code for faster performance
 201   // Start Bash code
 202   // Update the predictor
 203   Time current_time = g_eventQueue_ptr->getTime();
 204   while ((current_time - m_last_bandwidth_sample) > ADJUST_INTERVAL) {
 205     // Used less bandwidth
 206     m_bash_counter--;
 207
 208     // Make sure we don't overflow
 209     m_bash_counter = min(HIGH_RANGE, m_bash_counter);
 210     m_bash_counter = max(0, m_bash_counter);
 211
 212     // Reset samples
 213     m_last_bandwidth_sample += ADJUST_INTERVAL;
 214     m_bandwidth_since_sample = 0;
 215   }
 216   // End Bash code
 217
 218   if ((bw_remaining > 0) && !schedule_wakeup) {
 219     // We have extra bandwidth and our output buffer was available, so we must not have anything else to do until another message arrives.
 220     DEBUG_MSG(NETWORK_COMP,LowPrio,*this);
 221     DEBUG_MSG(NETWORK_COMP,LowPrio,"not scheduled again");
 222   } else {
 223     DEBUG_MSG(NETWORK_COMP,LowPrio,*this);
 224     DEBUG_MSG(NETWORK_COMP,LowPrio,"scheduled again");
 225     // We are out of bandwidth for this cycle, so wakeup next cycle and continue
 226     g_eventQueue_ptr->scheduleEvent(this, 1);
 227   }
 228 }
 229
 230 bool Throttle::broadcastBandwidthAvailable(int rand) const
 231 {
 232   bool result =  !(m_bash_counter > ((HIGH_RANGE/4) + (rand % (HIGH_RANGE/2))));
 233   return result;
 234 }
 235
 236 void Throttle::printStats(ostream& out) const
 237 {
 238   out << "utilized_percent: " << getUtilization() << endl;
 239 }
 240
 241 void Throttle::clearStats()
 242 {
 243   m_ruby_start = g_eventQueue_ptr->getTime();
 244   m_links_utilized = 0.0;
 245
 246   for (int i=0; i<m_message_counters.size(); i++) {
 247     for (int j=0; j<m_message_counters[i].size(); j++) {
 248       m_message_counters[i][j] = 0;
 249     }
 250   }
 251 }
 252
 253 void Throttle::printConfig(ostream& out) const
 254 {
 255
 256 }
 257
 258 double Throttle::getUtilization() const
 259 {
 260   return (100.0 * double(m_links_utilized)) / (double(g_eventQueue_ptr->getTime()-m_ruby_start));
 261 }
 262
 263 void Throttle::print(ostream& out) const
 264 {
 265   out << "[Throttle: " << m_sID << " " << m_node << " bw: " << getLinkBandwidth() << "]";
 266 }
 267
 268 // Helper function
 269
 270 static
 271 int network_message_to_size(NetworkMessage* net_msg_ptr)
 272 {
 273   assert(net_msg_ptr != NULL);
 274
 275   // Artificially increase the size of broadcast messages
 276   if (BROADCAST_SCALING > 1) {
 277     if (net_msg_ptr->getDestination().isBroadcast()) {
 278       return (RubySystem::getNetwork()->MessageSizeType_to_int(net_msg_ptr->getMessageSize()) * MESSAGE_SIZE_MULTIPLIER * BROADCAST_SCALING);
 279     }
 280   }
 281   return (RubySystem::getNetwork()->MessageSizeType_to_int(net_msg_ptr->getMessageSize()) * MESSAGE_SIZE_MULTIPLIER);
 282 }