Throttle.cc revision 8608:02d7ac5fb855 
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/cprintf.hh"
32#include "debug/RubyNetwork.hh"
33#include "mem/ruby/buffers/MessageBuffer.hh"
34#include "mem/ruby/network/simple/Throttle.hh"
35#include "mem/ruby/network/Network.hh"
36#include "mem/ruby/slicc_interface/NetworkMessage.hh"
37#include "mem/ruby/system/System.hh"
38
39using namespace std;
40
41const int HIGH_RANGE = 256;
42const int ADJUST_INTERVAL = 50000;
43const int MESSAGE_SIZE_MULTIPLIER = 1000;
44//const int BROADCAST_SCALING = 4; // Have a 16p system act like a 64p systems
45const int BROADCAST_SCALING = 1;
46const int PRIORITY_SWITCH_LIMIT = 128;
47
48static int network_message_to_size(NetworkMessage* net_msg_ptr);
49
50Throttle::Throttle(int sID, NodeID node, int link_latency,
51                   int link_bandwidth_multiplier, int endpoint_bandwidth)
52{
53    init(node, link_latency, link_bandwidth_multiplier, endpoint_bandwidth);
54    m_sID = sID;
55}
56
57Throttle::Throttle(NodeID node, int link_latency,
58                   int link_bandwidth_multiplier, int endpoint_bandwidth)
59{
60    init(node, link_latency, link_bandwidth_multiplier, endpoint_bandwidth);
61    m_sID = 0;
62}
63
64void
65Throttle::init(NodeID node, int link_latency, int link_bandwidth_multiplier,
66               int endpoint_bandwidth)
67{
68    m_node = node;
69    m_vnets = 0;
70
71    assert(link_bandwidth_multiplier > 0);
72    m_link_bandwidth_multiplier = link_bandwidth_multiplier;
73    m_link_latency = link_latency;
74    m_endpoint_bandwidth = endpoint_bandwidth;
75
76    m_wakeups_wo_switch = 0;
77    clearStats();
78}
79
80void
81Throttle::clear()
82{
83    for (int counter = 0; counter < m_vnets; counter++) {
84        m_in[counter]->clear();
85        m_out[counter]->clear();
86    }
87}
88
89void
90Throttle::addLinks(const std::vector<MessageBuffer*>& in_vec,
91    const std::vector<MessageBuffer*>& out_vec)
92{
93    assert(in_vec.size() == out_vec.size());
94    for (int i=0; i<in_vec.size(); i++) {
95        addVirtualNetwork(in_vec[i], out_vec[i]);
96    }
97
98    m_message_counters.resize(MessageSizeType_NUM);
99    for (int i = 0; i < MessageSizeType_NUM; i++) {
100        m_message_counters[i].resize(in_vec.size());
101        for (int j = 0; j<m_message_counters[i].size(); j++) {
102            m_message_counters[i][j] = 0;
103        }
104    }
105}
106
107void
108Throttle::addVirtualNetwork(MessageBuffer* in_ptr, MessageBuffer* out_ptr)
109{
110    m_units_remaining.push_back(0);
111    m_in.push_back(in_ptr);
112    m_out.push_back(out_ptr);
113
114    // Set consumer and description
115    m_in[m_vnets]->setConsumer(this);
116    string desc = "[Queue to Throttle " + to_string(m_sID) + " " +
117        to_string(m_node) + "]";
118    m_in[m_vnets]->setDescription(desc);
119    m_vnets++;
120}
121
122void
123Throttle::wakeup()
124{
125    // Limits the number of message sent to a limited number of bytes/cycle.
126    assert(getLinkBandwidth() > 0);
127    int bw_remaining = getLinkBandwidth();
128
129    // Give the highest numbered link priority most of the time
130    m_wakeups_wo_switch++;
131    int highest_prio_vnet = m_vnets-1;
132    int lowest_prio_vnet = 0;
133    int counter = 1;
134    bool schedule_wakeup = false;
135
136    // invert priorities to avoid starvation seen in the component network
137    if (m_wakeups_wo_switch > PRIORITY_SWITCH_LIMIT) {
138        m_wakeups_wo_switch = 0;
139        highest_prio_vnet = 0;
140        lowest_prio_vnet = m_vnets-1;
141        counter = -1;
142    }
143
144    for (int vnet = highest_prio_vnet;
145         (vnet * counter) >= (counter * lowest_prio_vnet);
146         vnet -= counter) {
147
148        assert(m_out[vnet] != NULL);
149        assert(m_in[vnet] != NULL);
150        assert(m_units_remaining[vnet] >= 0);
151
152        while (bw_remaining > 0 &&
153            (m_in[vnet]->isReady() || m_units_remaining[vnet] > 0) &&
154            m_out[vnet]->areNSlotsAvailable(1)) {
155
156            // See if we are done transferring the previous message on
157            // this virtual network
158            if (m_units_remaining[vnet] == 0 && m_in[vnet]->isReady()) {
159                // Find the size of the message we are moving
160                MsgPtr msg_ptr = m_in[vnet]->peekMsgPtr();
161                NetworkMessage* net_msg_ptr =
162                    safe_cast<NetworkMessage*>(msg_ptr.get());
163                m_units_remaining[vnet] +=
164                    network_message_to_size(net_msg_ptr);
165
166                DPRINTF(RubyNetwork, "throttle: %d my bw %d bw spent "
167                        "enqueueing net msg %d time: %lld.\n",
168                        m_node, getLinkBandwidth(), m_units_remaining[vnet],
169                        g_eventQueue_ptr->getTime());
170
171                // Move the message
172                m_out[vnet]->enqueue(m_in[vnet]->peekMsgPtr(), m_link_latency);
173                m_in[vnet]->pop();
174
175                // Count the message
176                m_message_counters[net_msg_ptr->getMessageSize()][vnet]++;
177
178                DPRINTF(RubyNetwork, "%s\n", *m_out[vnet]);
179            }
180
181            // Calculate the amount of bandwidth we spent on this message
182            int diff = m_units_remaining[vnet] - bw_remaining;
183            m_units_remaining[vnet] = max(0, diff);
184            bw_remaining = max(0, -diff);
185        }
186
187        if (bw_remaining > 0 &&
188            (m_in[vnet]->isReady() || m_units_remaining[vnet] > 0) &&
189            !m_out[vnet]->areNSlotsAvailable(1)) {
190            DPRINTF(RubyNetwork, "vnet: %d", vnet);
191            // schedule me to wakeup again because I'm waiting for my
192            // output queue to become available
193            schedule_wakeup = true;
194        }
195    }
196
197    // We should only wake up when we use the bandwidth
198    // This is only mostly true
199    // assert(bw_remaining != getLinkBandwidth());
200
201    // Record that we used some or all of the link bandwidth this cycle
202    double ratio = 1.0 - (double(bw_remaining) / double(getLinkBandwidth()));
203
204    // If ratio = 0, we used no bandwidth, if ratio = 1, we used all
205    linkUtilized(ratio);
206
207    if (bw_remaining > 0 && !schedule_wakeup) {
208        // We have extra bandwidth and our output buffer was
209        // available, so we must not have anything else to do until
210        // another message arrives.
211        DPRINTF(RubyNetwork, "%s not scheduled again\n", *this);
212    } else {
213        DPRINTF(RubyNetwork, "%s scheduled again\n", *this);
214
215        // We are out of bandwidth for this cycle, so wakeup next
216        // cycle and continue
217        g_eventQueue_ptr->scheduleEvent(this, 1);
218    }
219}
220
221void
222Throttle::printStats(ostream& out) const
223{
224    out << "utilized_percent: " << getUtilization() << endl;
225}
226
227void
228Throttle::clearStats()
229{
230    m_ruby_start = g_eventQueue_ptr->getTime();
231    m_links_utilized = 0.0;
232
233    for (int i = 0; i < m_message_counters.size(); i++) {
234        for (int j = 0; j < m_message_counters[i].size(); j++) {
235            m_message_counters[i][j] = 0;
236        }
237    }
238}
239
240void
241Throttle::printConfig(ostream& out) const
242{
243}
244
245double
246Throttle::getUtilization() const
247{
248    return 100.0 * double(m_links_utilized) /
249        double(g_eventQueue_ptr->getTime()-m_ruby_start);
250}
251
252void
253Throttle::print(ostream& out) const
254{
255    ccprintf(out,  "[%i bw: %i]", m_node, getLinkBandwidth());
256}
257
258int
259network_message_to_size(NetworkMessage* net_msg_ptr)
260{
261    assert(net_msg_ptr != NULL);
262
263    int size = RubySystem::getNetwork()->
264        MessageSizeType_to_int(net_msg_ptr->getMessageSize());
265    size *=  MESSAGE_SIZE_MULTIPLIER;
266
267    // Artificially increase the size of broadcast messages
268    if (BROADCAST_SCALING > 1 && net_msg_ptr->getDestination().isBroadcast())
269        size *= BROADCAST_SCALING;
270
271    return size;
272}
273