Throttle.cc revision 9117:49116b947194 
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 HIGH_RANGE = 256;
43const int ADJUST_INTERVAL = 50000;
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(NetworkMessage* net_msg_ptr);
50
51Throttle::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
58Throttle::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
65void
66Throttle::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
81void
82Throttle::clear()
83{
84    for (int counter = 0; counter < m_vnets; counter++) {
85        m_in[counter]->clear();
86        m_out[counter]->clear();
87    }
88}
89
90void
91Throttle::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
108void
109Throttle::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
123void
124Throttle::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
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
241double
242Throttle::getUtilization() const
243{
244    return 100.0 * double(m_links_utilized) /
245        double(g_eventQueue_ptr->getTime()-m_ruby_start);
246}
247
248void
249Throttle::print(ostream& out) const
250{
251    ccprintf(out,  "[%i bw: %i]", m_node, getLinkBandwidth());
252}
253
254int
255network_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}
269