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

   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 <cassert>
  30
  31 #include "base/cast.hh"
  32 #include "base/cprintf.hh"
  33 #include "debug/RubyNetwork.hh"
  34 #include "mem/ruby/buffers/MessageBuffer.hh"
  35 #include "mem/ruby/network/simple/Throttle.hh"
  36 #include "mem/ruby/network/Network.hh"
  37 #include "mem/ruby/slicc_interface/NetworkMessage.hh"
  38 #include "mem/ruby/system/System.hh"
  39
  40 using namespace std;
  41
  42 const int HIGH_RANGE = 256;
  43 const int ADJUST_INTERVAL = 50000;
  44 const int MESSAGE_SIZE_MULTIPLIER = 1000;
  45 //const int BROADCAST_SCALING = 4; // Have a 16p system act like a 64p systems
  46 const int BROADCAST_SCALING = 1;
  47 const int PRIORITY_SWITCH_LIMIT = 128;
  48
  49 static int network_message_to_size(NetworkMessage* net_msg_ptr);
  50
  51 Throttle::Throttle(int sID, NodeID node, int link_latency,
  52                    int link_bandwidth_multiplier, int endpoint_bandwidth)
  53 {
  54     init(node, link_latency, link_bandwidth_multiplier, endpoint_bandwidth);
  55     m_sID = sID;
  56 }
  57
  58 Throttle::Throttle(NodeID node, int link_latency,
  59                    int link_bandwidth_multiplier, int endpoint_bandwidth)
  60 {
  61     init(node, link_latency, link_bandwidth_multiplier, endpoint_bandwidth);
  62     m_sID = 0;
  63 }
  64
  65 void
  66 Throttle::init(NodeID node, int link_latency, int link_bandwidth_multiplier,
  67                int endpoint_bandwidth)
  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     m_endpoint_bandwidth = endpoint_bandwidth;
  76
  77     m_wakeups_wo_switch = 0;
  78     clearStats();
  79 }
  80
  81 void
  82 Throttle::clear()
  83 {
  84     for (int counter = 0; counter < m_vnets; counter++) {
  85         m_in[counter]->clear();
  86         m_out[counter]->clear();
  87     }
  88 }
  89
  90 void
  91 Throttle::addLinks(const std::vector<MessageBuffer*>& in_vec,
  92     const std::vector<MessageBuffer*>& out_vec)
  93 {
  94     assert(in_vec.size() == out_vec.size());
  95     for (int i=0; i<in_vec.size(); i++) {
  96         addVirtualNetwork(in_vec[i], out_vec[i]);
  97     }
  98
  99     m_message_counters.resize(MessageSizeType_NUM);
 100     for (int i = 0; i < MessageSizeType_NUM; i++) {
 101         m_message_counters[i].resize(in_vec.size());
 102         for (int j = 0; j<m_message_counters[i].size(); j++) {
 103             m_message_counters[i][j] = 0;
 104         }
 105     }
 106 }
 107
 108 void
 109 Throttle::addVirtualNetwork(MessageBuffer* in_ptr, MessageBuffer* out_ptr)
 110 {
 111     m_units_remaining.push_back(0);
 112     m_in.push_back(in_ptr);
 113     m_out.push_back(out_ptr);
 114
 115     // Set consumer and description
 116     m_in[m_vnets]->setConsumer(this);
 117     string desc = "[Queue to Throttle " + to_string(m_sID) + " " +
 118         to_string(m_node) + "]";
 119     m_in[m_vnets]->setDescription(desc);
 120     m_vnets++;
 121 }
 122
 123 void
 124 Throttle::wakeup()
 125 {
 126     // Limits the number of message sent to a limited number of bytes/cycle.
 127     assert(getLinkBandwidth() > 0);
 128     int bw_remaining = getLinkBandwidth();
 129
 130     // Give the highest numbered link priority most of the time
 131     m_wakeups_wo_switch++;
 132     int highest_prio_vnet = m_vnets-1;
 133     int lowest_prio_vnet = 0;
 134     int counter = 1;
 135     bool schedule_wakeup = false;
 136
 137     // invert priorities to avoid starvation seen in the component network
 138     if (m_wakeups_wo_switch > PRIORITY_SWITCH_LIMIT) {
 139         m_wakeups_wo_switch = 0;
 140         highest_prio_vnet = 0;
 141         lowest_prio_vnet = m_vnets-1;
 142         counter = -1;
 143     }
 144
 145     for (int vnet = highest_prio_vnet;
 146          (vnet * counter) >= (counter * lowest_prio_vnet);
 147          vnet -= counter) {
 148
 149         assert(m_out[vnet] != NULL);
 150         assert(m_in[vnet] != NULL);
 151         assert(m_units_remaining[vnet] >= 0);
 152
 153         while (bw_remaining > 0 &&
 154             (m_in[vnet]->isReady() || m_units_remaining[vnet] > 0) &&
 155             m_out[vnet]->areNSlotsAvailable(1)) {
 156
 157             // See if we are done transferring the previous message on
 158             // this virtual network
 159             if (m_units_remaining[vnet] == 0 && m_in[vnet]->isReady()) {
 160                 // Find the size of the message we are moving
 161                 MsgPtr msg_ptr = m_in[vnet]->peekMsgPtr();
 162                 NetworkMessage* net_msg_ptr =
 163                     safe_cast<NetworkMessage*>(msg_ptr.get());
 164                 m_units_remaining[vnet] +=
 165                     network_message_to_size(net_msg_ptr);
 166
 167                 DPRINTF(RubyNetwork, "throttle: %d my bw %d bw spent "
 168                         "enqueueing net msg %d time: %lld.\n",
 169                         m_node, getLinkBandwidth(), m_units_remaining[vnet],
 170                         g_eventQueue_ptr->getTime());
 171
 172                 // Move the message
 173                 m_out[vnet]->enqueue(m_in[vnet]->peekMsgPtr(), m_link_latency);
 174                 m_in[vnet]->pop();
 175
 176                 // Count the message
 177                 m_message_counters[net_msg_ptr->getMessageSize()][vnet]++;
 178
 179                 DPRINTF(RubyNetwork, "%s\n", *m_out[vnet]);
 180             }
 181
 182             // Calculate the amount of bandwidth we spent on this message
 183             int diff = m_units_remaining[vnet] - bw_remaining;
 184             m_units_remaining[vnet] = max(0, diff);
 185             bw_remaining = max(0, -diff);
 186         }
 187
 188         if (bw_remaining > 0 &&
 189             (m_in[vnet]->isReady() || m_units_remaining[vnet] > 0) &&
 190             !m_out[vnet]->areNSlotsAvailable(1)) {
 191             DPRINTF(RubyNetwork, "vnet: %d", vnet);
 192             // schedule me to wakeup again because I'm waiting for my
 193             // output queue to become available
 194             schedule_wakeup = true;
 195         }
 196     }
 197
 198     // We should only wake up when we use the bandwidth
 199     // This is only mostly true
 200     // assert(bw_remaining != getLinkBandwidth());
 201
 202     // Record that we used some or all of the link bandwidth this cycle
 203     double ratio = 1.0 - (double(bw_remaining) / double(getLinkBandwidth()));
 204
 205     // If ratio = 0, we used no bandwidth, if ratio = 1, we used all
 206     linkUtilized(ratio);
 207
 208     if (bw_remaining > 0 && !schedule_wakeup) {
 209         // We have extra bandwidth and our output buffer was
 210         // available, so we must not have anything else to do until
 211         // another message arrives.
 212         DPRINTF(RubyNetwork, "%s not scheduled again\n", *this);
 213     } else {
 214         DPRINTF(RubyNetwork, "%s scheduled again\n", *this);
 215
 216         // We are out of bandwidth for this cycle, so wakeup next
 217         // cycle and continue
 218         g_eventQueue_ptr->scheduleEvent(this, 1);
 219     }
 220 }
 221
 222 void
 223 Throttle::printStats(ostream& out) const
 224 {
 225     out << "utilized_percent: " << getUtilization() << endl;
 226 }
 227
 228 void
 229 Throttle::clearStats()
 230 {
 231     m_ruby_start = g_eventQueue_ptr->getTime();
 232     m_links_utilized = 0.0;
 233
 234     for (int i = 0; i < m_message_counters.size(); i++) {
 235         for (int j = 0; j < m_message_counters[i].size(); j++) {
 236             m_message_counters[i][j] = 0;
 237         }
 238     }
 239 }
 240
 241 double
 242 Throttle::getUtilization() const
 243 {
 244     return 100.0 * double(m_links_utilized) /
 245         double(g_eventQueue_ptr->getTime()-m_ruby_start);
 246 }
 247
 248 void
 249 Throttle::print(ostream& out) const
 250 {
 251     ccprintf(out,  "[%i bw: %i]", m_node, getLinkBandwidth());
 252 }
 253
 254 int
 255 network_message_to_size(NetworkMessage* net_msg_ptr)
 256 {
 257     assert(net_msg_ptr != NULL);
 258
 259     int size = RubySystem::getNetwork()->
 260         MessageSizeType_to_int(net_msg_ptr->getMessageSize());
 261     size *=  MESSAGE_SIZE_MULTIPLIER;
 262
 263     // Artificially increase the size of broadcast messages
 264     if (BROADCAST_SCALING > 1 && net_msg_ptr->getDestination().isBroadcast())
 265         size *= BROADCAST_SCALING;
 266
 267     return size;
 268 }