Throttle.cc revision 10226
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 40using namespace std; 41 42const int MESSAGE_SIZE_MULTIPLIER = 1000; 43//const int BROADCAST_SCALING = 4; // Have a 16p system act like a 64p systems 44const int BROADCAST_SCALING = 1; 45const int PRIORITY_SWITCH_LIMIT = 128; 46 47static int network_message_to_size(NetworkMessage* net_msg_ptr); 48 49Throttle::Throttle(int sID, NodeID node, Cycles link_latency, 50 int link_bandwidth_multiplier, int endpoint_bandwidth, 51 ClockedObject *em) 52 : Consumer(em) 53{ 54 init(node, link_latency, link_bandwidth_multiplier, endpoint_bandwidth); 55 m_sID = sID; 56} 57 58Throttle::Throttle(NodeID node, Cycles link_latency, 59 int link_bandwidth_multiplier, int endpoint_bandwidth, 60 ClockedObject *em) 61 : Consumer(em) 62{ 63 init(node, link_latency, link_bandwidth_multiplier, endpoint_bandwidth); 64 m_sID = 0; 65} 66 67void 68Throttle::init(NodeID node, Cycles link_latency, 69 int link_bandwidth_multiplier, int endpoint_bandwidth) 70{ 71 m_node = node; 72 m_vnets = 0; 73 74 assert(link_bandwidth_multiplier > 0); 75 m_link_bandwidth_multiplier = link_bandwidth_multiplier; 76 m_link_latency = link_latency; 77 m_endpoint_bandwidth = endpoint_bandwidth; 78 79 m_wakeups_wo_switch = 0; 80 81 m_link_utilization_proxy = 0; 82} 83 84void 85Throttle::addLinks(const std::vector<MessageBuffer*>& in_vec, 86 const std::vector<MessageBuffer*>& out_vec) 87{ 88 assert(in_vec.size() == out_vec.size()); 89 for (int i=0; i<in_vec.size(); i++) { 90 addVirtualNetwork(in_vec[i], out_vec[i]); 91 } 92} 93 94void 95Throttle::addVirtualNetwork(MessageBuffer* in_ptr, MessageBuffer* out_ptr) 96{ 97 m_units_remaining.push_back(0); 98 m_in.push_back(in_ptr); 99 m_out.push_back(out_ptr); 100 101 // Set consumer and description 102 m_in[m_vnets]->setConsumer(this); 103 104 string desc = "[Queue to Throttle " + to_string(m_sID) + " " + 105 to_string(m_node) + "]"; 106 m_in[m_vnets]->setDescription(desc); 107 m_vnets++; 108} 109 110void 111Throttle::wakeup() 112{ 113 // Limits the number of message sent to a limited number of bytes/cycle. 114 assert(getLinkBandwidth() > 0); 115 int bw_remaining = getLinkBandwidth(); 116 117 // Give the highest numbered link priority most of the time 118 m_wakeups_wo_switch++; 119 int highest_prio_vnet = m_vnets-1; 120 int lowest_prio_vnet = 0; 121 int counter = 1; 122 bool schedule_wakeup = false; 123 124 // invert priorities to avoid starvation seen in the component network 125 if (m_wakeups_wo_switch > PRIORITY_SWITCH_LIMIT) { 126 m_wakeups_wo_switch = 0; 127 highest_prio_vnet = 0; 128 lowest_prio_vnet = m_vnets-1; 129 counter = -1; 130 } 131 132 for (int vnet = highest_prio_vnet; 133 (vnet * counter) >= (counter * lowest_prio_vnet); 134 vnet -= counter) { 135 136 assert(m_out[vnet] != NULL); 137 assert(m_in[vnet] != NULL); 138 assert(m_units_remaining[vnet] >= 0); 139 140 while (bw_remaining > 0 && 141 (m_in[vnet]->isReady() || m_units_remaining[vnet] > 0) && 142 m_out[vnet]->areNSlotsAvailable(1)) { 143 144 // See if we are done transferring the previous message on 145 // this virtual network 146 if (m_units_remaining[vnet] == 0 && m_in[vnet]->isReady()) { 147 // Find the size of the message we are moving 148 MsgPtr msg_ptr = m_in[vnet]->peekMsgPtr(); 149 NetworkMessage* net_msg_ptr = 150 safe_cast<NetworkMessage*>(msg_ptr.get()); 151 m_units_remaining[vnet] += 152 network_message_to_size(net_msg_ptr); 153 154 DPRINTF(RubyNetwork, "throttle: %d my bw %d bw spent " 155 "enqueueing net msg %d time: %lld.\n", 156 m_node, getLinkBandwidth(), m_units_remaining[vnet], 157 g_system_ptr->curCycle()); 158 159 // Move the message 160 m_in[vnet]->dequeue(); 161 m_out[vnet]->enqueue(msg_ptr, m_link_latency); 162 163 // Count the message 164 m_msg_counts[net_msg_ptr->getMessageSize()][vnet]++; 165 166 DPRINTF(RubyNetwork, "%s\n", *m_out[vnet]); 167 } 168 169 // Calculate the amount of bandwidth we spent on this message 170 int diff = m_units_remaining[vnet] - bw_remaining; 171 m_units_remaining[vnet] = max(0, diff); 172 bw_remaining = max(0, -diff); 173 } 174 175 if (bw_remaining > 0 && 176 (m_in[vnet]->isReady() || m_units_remaining[vnet] > 0) && 177 !m_out[vnet]->areNSlotsAvailable(1)) { 178 DPRINTF(RubyNetwork, "vnet: %d", vnet); 179 // schedule me to wakeup again because I'm waiting for my 180 // output queue to become available 181 schedule_wakeup = true; 182 } 183 } 184 185 // We should only wake up when we use the bandwidth 186 // This is only mostly true 187 // assert(bw_remaining != getLinkBandwidth()); 188 189 // Record that we used some or all of the link bandwidth this cycle 190 double ratio = 1.0 - (double(bw_remaining) / double(getLinkBandwidth())); 191 192 // If ratio = 0, we used no bandwidth, if ratio = 1, we used all 193 m_link_utilization_proxy += ratio; 194 195 if (bw_remaining > 0 && !schedule_wakeup) { 196 // We have extra bandwidth and our output buffer was 197 // available, so we must not have anything else to do until 198 // another message arrives. 199 DPRINTF(RubyNetwork, "%s not scheduled again\n", *this); 200 } else { 201 DPRINTF(RubyNetwork, "%s scheduled again\n", *this); 202 203 // We are out of bandwidth for this cycle, so wakeup next 204 // cycle and continue 205 scheduleEvent(Cycles(1)); 206 } 207} 208 209void 210Throttle::regStats(string parent) 211{ 212 m_link_utilization 213 .name(parent + csprintf(".throttle%i", m_node) + ".link_utilization"); 214 215 for (MessageSizeType type = MessageSizeType_FIRST; 216 type < MessageSizeType_NUM; ++type) { 217 m_msg_counts[(unsigned int)type] 218 .init(m_vnets) 219 .name(parent + csprintf(".throttle%i", m_node) + ".msg_count." + 220 MessageSizeType_to_string(type)) 221 .flags(Stats::nozero) 222 ; 223 m_msg_bytes[(unsigned int) type] 224 .name(parent + csprintf(".throttle%i", m_node) + ".msg_bytes." + 225 MessageSizeType_to_string(type)) 226 .flags(Stats::nozero) 227 ; 228 229 m_msg_bytes[(unsigned int) type] = m_msg_counts[type] * Stats::constant( 230 Network::MessageSizeType_to_int(type)); 231 } 232} 233 234void 235Throttle::clearStats() 236{ 237 m_link_utilization_proxy = 0; 238} 239 240void 241Throttle::collateStats() 242{ 243 m_link_utilization = 100.0 * m_link_utilization_proxy 244 / (double(g_system_ptr->curCycle() - g_ruby_start)); 245} 246 247void 248Throttle::print(ostream& out) const 249{ 250 ccprintf(out, "[%i bw: %i]", m_node, getLinkBandwidth()); 251} 252 253int 254network_message_to_size(NetworkMessage* net_msg_ptr) 255{ 256 assert(net_msg_ptr != NULL); 257 258 int size = Network::MessageSizeType_to_int(net_msg_ptr->getMessageSize()); 259 size *= MESSAGE_SIZE_MULTIPLIER; 260 261 // Artificially increase the size of broadcast messages 262 if (BROADCAST_SCALING > 1 && net_msg_ptr->getDestination().isBroadcast()) 263 size *= BROADCAST_SCALING; 264 265 return size; 266} 267