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