Throttle.cc revision 7054 
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 "base/cprintf.hh"
30#include "mem/protocol/Protocol.hh"
31#include "mem/ruby/buffers/MessageBuffer.hh"
32#include "mem/ruby/network/Network.hh"
33#include "mem/ruby/network/simple/Throttle.hh"
34#include "mem/ruby/slicc_interface/NetworkMessage.hh"
35#include "mem/ruby/system/System.hh"
36
37const int HIGH_RANGE = 256;
38const int ADJUST_INTERVAL = 50000;
39const int MESSAGE_SIZE_MULTIPLIER = 1000;
40//const int BROADCAST_SCALING = 4; // Have a 16p system act like a 64p systems
41const int BROADCAST_SCALING = 1;
42const int PRIORITY_SWITCH_LIMIT = 128;
43
44static int network_message_to_size(NetworkMessage* net_msg_ptr);
45
46extern std::ostream *debug_cout_ptr;
47
48Throttle::Throttle(int sID, NodeID node, int link_latency,
49    int link_bandwidth_multiplier)
50{
51    init(node, link_latency, link_bandwidth_multiplier);
52    m_sID = sID;
53}
54
55Throttle::Throttle(NodeID node, int link_latency,
56    int link_bandwidth_multiplier)
57{
58    init(node, link_latency, link_bandwidth_multiplier);
59    m_sID = 0;
60}
61
62void
63Throttle::init(NodeID node, int link_latency, int link_bandwidth_multiplier)
64{
65    m_node = node;
66    m_vnets = 0;
67
68    ASSERT(link_bandwidth_multiplier > 0);
69    m_link_bandwidth_multiplier = link_bandwidth_multiplier;
70    m_link_latency = link_latency;
71
72    m_wakeups_wo_switch = 0;
73    clearStats();
74}
75
76void
77Throttle::clear()
78{
79    for (int counter = 0; counter < m_vnets; counter++) {
80        m_in[counter]->clear();
81        m_out[counter]->clear();
82    }
83}
84
85void
86Throttle::addLinks(const Vector<MessageBuffer*>& in_vec,
87    const Vector<MessageBuffer*>& out_vec)
88{
89    assert(in_vec.size() == out_vec.size());
90    for (int i=0; i<in_vec.size(); i++) {
91        addVirtualNetwork(in_vec[i], out_vec[i]);
92    }
93
94    m_message_counters.setSize(MessageSizeType_NUM);
95    for (int i = 0; i < MessageSizeType_NUM; i++) {
96        m_message_counters[i].setSize(in_vec.size());
97        for (int j = 0; j<m_message_counters[i].size(); j++) {
98            m_message_counters[i][j] = 0;
99        }
100    }
101}
102
103void
104Throttle::addVirtualNetwork(MessageBuffer* in_ptr, MessageBuffer* out_ptr)
105{
106    m_units_remaining.insertAtBottom(0);
107    m_in.insertAtBottom(in_ptr);
108    m_out.insertAtBottom(out_ptr);
109
110    // Set consumer and description
111    m_in[m_vnets]->setConsumer(this);
112    string desc = "[Queue to Throttle " + NodeIDToString(m_sID) + " " +
113        NodeIDToString(m_node) + "]";
114    m_in[m_vnets]->setDescription(desc);
115    m_vnets++;
116}
117
118void
119Throttle::wakeup()
120{
121    // Limits the number of message sent to a limited number of bytes/cycle.
122    assert(getLinkBandwidth() > 0);
123    int bw_remaining = getLinkBandwidth();
124
125    // Give the highest numbered link priority most of the time
126    m_wakeups_wo_switch++;
127    int highest_prio_vnet = m_vnets-1;
128    int lowest_prio_vnet = 0;
129    int counter = 1;
130    bool schedule_wakeup = false;
131
132    // invert priorities to avoid starvation seen in the component network
133    if (m_wakeups_wo_switch > PRIORITY_SWITCH_LIMIT) {
134        m_wakeups_wo_switch = 0;
135        highest_prio_vnet = 0;
136        lowest_prio_vnet = m_vnets-1;
137        counter = -1;
138    }
139
140    for (int vnet = highest_prio_vnet;
141         (vnet * counter) >= (counter * lowest_prio_vnet);
142         vnet -= counter) {
143
144        assert(m_out[vnet] != NULL);
145        assert(m_in[vnet] != NULL);
146        assert(m_units_remaining[vnet] >= 0);
147
148        while (bw_remaining > 0 &&
149            (m_in[vnet]->isReady() || m_units_remaining[vnet] > 0) &&
150            m_out[vnet]->areNSlotsAvailable(1)) {
151
152            // See if we are done transferring the previous message on
153            // this virtual network
154            if (m_units_remaining[vnet] == 0 && m_in[vnet]->isReady()) {
155                // Find the size of the message we are moving
156                MsgPtr msg_ptr = m_in[vnet]->peekMsgPtr();
157                NetworkMessage* net_msg_ptr =
158                    safe_cast<NetworkMessage*>(msg_ptr.ref());
159                m_units_remaining[vnet] +=
160                    network_message_to_size(net_msg_ptr);
161
162                DEBUG_NEWLINE(NETWORK_COMP,HighPrio);
163                DEBUG_MSG(NETWORK_COMP, HighPrio,
164                    csprintf("throttle: %d my bw %d bw spent enqueueing "
165                        "net msg %d time: %d.",
166                        m_node, getLinkBandwidth(), m_units_remaining[vnet],
167                        g_eventQueue_ptr->getTime()));
168
169                // Move the message
170                m_out[vnet]->enqueue(m_in[vnet]->peekMsgPtr(), m_link_latency);
171                m_in[vnet]->pop();
172
173                // Count the message
174                m_message_counters[net_msg_ptr->getMessageSize()][vnet]++;
175
176                DEBUG_MSG(NETWORK_COMP,LowPrio,*m_out[vnet]);
177                DEBUG_NEWLINE(NETWORK_COMP,HighPrio);
178            }
179
180            // Calculate the amount of bandwidth we spent on this message
181            int diff = m_units_remaining[vnet] - bw_remaining;
182            m_units_remaining[vnet] = max(0, diff);
183            bw_remaining = max(0, -diff);
184        }
185
186        if (bw_remaining > 0 &&
187            (m_in[vnet]->isReady() || m_units_remaining[vnet] > 0) &&
188            !m_out[vnet]->areNSlotsAvailable(1)) {
189            DEBUG_MSG(NETWORK_COMP,LowPrio,vnet);
190            // schedule me to wakeup again because I'm waiting for my
191            // output queue to become available
192            schedule_wakeup = true;
193        }
194    }
195
196    // We should only wake up when we use the bandwidth
197    // This is only mostly true
198    // assert(bw_remaining != getLinkBandwidth());
199
200    // Record that we used some or all of the link bandwidth this cycle
201    double ratio = 1.0 - (double(bw_remaining) / double(getLinkBandwidth()));
202
203    // If ratio = 0, we used no bandwidth, if ratio = 1, we used all
204    linkUtilized(ratio);
205
206    if (bw_remaining > 0 && !schedule_wakeup) {
207        // We have extra bandwidth and our output buffer was
208        // available, so we must not have anything else to do until
209        // another message arrives.
210        DEBUG_MSG(NETWORK_COMP, LowPrio, *this);
211        DEBUG_MSG(NETWORK_COMP, LowPrio, "not scheduled again");
212    } else {
213        DEBUG_MSG(NETWORK_COMP, LowPrio, *this);
214        DEBUG_MSG(NETWORK_COMP, LowPrio, "scheduled again");
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
222void
223Throttle::printStats(ostream& out) const
224{
225    out << "utilized_percent: " << getUtilization() << endl;
226}
227
228void
229Throttle::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
241void
242Throttle::printConfig(ostream& out) const
243{
244}
245
246double
247Throttle::getUtilization() const
248{
249    return 100.0 * double(m_links_utilized) /
250        double(g_eventQueue_ptr->getTime()-m_ruby_start);
251}
252
253void
254Throttle::print(ostream& out) const
255{
256    out << "[Throttle: " << m_sID << " " << m_node
257        << " bw: " << getLinkBandwidth() << "]";
258}
259
260int
261network_message_to_size(NetworkMessage* net_msg_ptr)
262{
263    assert(net_msg_ptr != NULL);
264
265    int size = RubySystem::getNetwork()->
266        MessageSizeType_to_int(net_msg_ptr->getMessageSize());
267    size *=  MESSAGE_SIZE_MULTIPLIER;
268
269    // Artificially increase the size of broadcast messages
270    if (BROADCAST_SCALING > 1 && net_msg_ptr->getDestination().isBroadcast())
271        size *= BROADCAST_SCALING;
272
273    return size;
274}
275