Throttle.cc revision 9275:ef43e69c837a 
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                   EventManager *em)
54    : Consumer(em)
55{
56    init(node, link_latency, link_bandwidth_multiplier, endpoint_bandwidth);
57    m_sID = sID;
58}
59
60Throttle::Throttle(NodeID node, int link_latency,
61                   int link_bandwidth_multiplier, int endpoint_bandwidth,
62                   EventManager *em)
63    : Consumer(em)
64{
65    init(node, link_latency, link_bandwidth_multiplier, endpoint_bandwidth);
66    m_sID = 0;
67}
68
69void
70Throttle::init(NodeID node, int link_latency, int link_bandwidth_multiplier,
71               int endpoint_bandwidth)
72{
73    m_node = node;
74    m_vnets = 0;
75
76    assert(link_bandwidth_multiplier > 0);
77    m_link_bandwidth_multiplier = link_bandwidth_multiplier;
78    m_link_latency = link_latency;
79    m_endpoint_bandwidth = endpoint_bandwidth;
80
81    m_wakeups_wo_switch = 0;
82    clearStats();
83}
84
85void
86Throttle::clear()
87{
88    for (int counter = 0; counter < m_vnets; counter++) {
89        m_in[counter]->clear();
90        m_out[counter]->clear();
91    }
92}
93
94void
95Throttle::addLinks(const std::vector<MessageBuffer*>& in_vec,
96    const std::vector<MessageBuffer*>& out_vec)
97{
98    assert(in_vec.size() == out_vec.size());
99    for (int i=0; i<in_vec.size(); i++) {
100        addVirtualNetwork(in_vec[i], out_vec[i]);
101    }
102
103    m_message_counters.resize(MessageSizeType_NUM);
104    for (int i = 0; i < MessageSizeType_NUM; i++) {
105        m_message_counters[i].resize(in_vec.size());
106        for (int j = 0; j<m_message_counters[i].size(); j++) {
107            m_message_counters[i][j] = 0;
108        }
109    }
110}
111
112void
113Throttle::addVirtualNetwork(MessageBuffer* in_ptr, MessageBuffer* out_ptr)
114{
115    m_units_remaining.push_back(0);
116    m_in.push_back(in_ptr);
117    m_out.push_back(out_ptr);
118
119    // Set consumer and description
120    m_in[m_vnets]->setConsumer(this);
121    string desc = "[Queue to Throttle " + to_string(m_sID) + " " +
122        to_string(m_node) + "]";
123    m_in[m_vnets]->setDescription(desc);
124    m_vnets++;
125}
126
127void
128Throttle::wakeup()
129{
130    // Limits the number of message sent to a limited number of bytes/cycle.
131    assert(getLinkBandwidth() > 0);
132    int bw_remaining = getLinkBandwidth();
133
134    // Give the highest numbered link priority most of the time
135    m_wakeups_wo_switch++;
136    int highest_prio_vnet = m_vnets-1;
137    int lowest_prio_vnet = 0;
138    int counter = 1;
139    bool schedule_wakeup = false;
140
141    // invert priorities to avoid starvation seen in the component network
142    if (m_wakeups_wo_switch > PRIORITY_SWITCH_LIMIT) {
143        m_wakeups_wo_switch = 0;
144        highest_prio_vnet = 0;
145        lowest_prio_vnet = m_vnets-1;
146        counter = -1;
147    }
148
149    for (int vnet = highest_prio_vnet;
150         (vnet * counter) >= (counter * lowest_prio_vnet);
151         vnet -= counter) {
152
153        assert(m_out[vnet] != NULL);
154        assert(m_in[vnet] != NULL);
155        assert(m_units_remaining[vnet] >= 0);
156
157        while (bw_remaining > 0 &&
158            (m_in[vnet]->isReady() || m_units_remaining[vnet] > 0) &&
159            m_out[vnet]->areNSlotsAvailable(1)) {
160
161            // See if we are done transferring the previous message on
162            // this virtual network
163            if (m_units_remaining[vnet] == 0 && m_in[vnet]->isReady()) {
164                // Find the size of the message we are moving
165                MsgPtr msg_ptr = m_in[vnet]->peekMsgPtr();
166                NetworkMessage* net_msg_ptr =
167                    safe_cast<NetworkMessage*>(msg_ptr.get());
168                m_units_remaining[vnet] +=
169                    network_message_to_size(net_msg_ptr);
170
171                DPRINTF(RubyNetwork, "throttle: %d my bw %d bw spent "
172                        "enqueueing net msg %d time: %lld.\n",
173                        m_node, getLinkBandwidth(), m_units_remaining[vnet],
174                        g_system_ptr->getTime());
175
176                // Move the message
177                m_out[vnet]->enqueue(m_in[vnet]->peekMsgPtr(), m_link_latency);
178                m_in[vnet]->pop();
179
180                // Count the message
181                m_message_counters[net_msg_ptr->getMessageSize()][vnet]++;
182
183                DPRINTF(RubyNetwork, "%s\n", *m_out[vnet]);
184            }
185
186            // Calculate the amount of bandwidth we spent on this message
187            int diff = m_units_remaining[vnet] - bw_remaining;
188            m_units_remaining[vnet] = max(0, diff);
189            bw_remaining = max(0, -diff);
190        }
191
192        if (bw_remaining > 0 &&
193            (m_in[vnet]->isReady() || m_units_remaining[vnet] > 0) &&
194            !m_out[vnet]->areNSlotsAvailable(1)) {
195            DPRINTF(RubyNetwork, "vnet: %d", vnet);
196            // schedule me to wakeup again because I'm waiting for my
197            // output queue to become available
198            schedule_wakeup = true;
199        }
200    }
201
202    // We should only wake up when we use the bandwidth
203    // This is only mostly true
204    // assert(bw_remaining != getLinkBandwidth());
205
206    // Record that we used some or all of the link bandwidth this cycle
207    double ratio = 1.0 - (double(bw_remaining) / double(getLinkBandwidth()));
208
209    // If ratio = 0, we used no bandwidth, if ratio = 1, we used all
210    linkUtilized(ratio);
211
212    if (bw_remaining > 0 && !schedule_wakeup) {
213        // We have extra bandwidth and our output buffer was
214        // available, so we must not have anything else to do until
215        // another message arrives.
216        DPRINTF(RubyNetwork, "%s not scheduled again\n", *this);
217    } else {
218        DPRINTF(RubyNetwork, "%s scheduled again\n", *this);
219
220        // We are out of bandwidth for this cycle, so wakeup next
221        // cycle and continue
222        scheduleEvent(1);
223    }
224}
225
226void
227Throttle::printStats(ostream& out) const
228{
229    out << "utilized_percent: " << getUtilization() << endl;
230}
231
232void
233Throttle::clearStats()
234{
235    m_ruby_start = g_system_ptr->getTime();
236    m_links_utilized = 0.0;
237
238    for (int i = 0; i < m_message_counters.size(); i++) {
239        for (int j = 0; j < m_message_counters[i].size(); j++) {
240            m_message_counters[i][j] = 0;
241        }
242    }
243}
244
245double
246Throttle::getUtilization() const
247{
248    return 100.0 * double(m_links_utilized) /
249        double(g_system_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 = Network::MessageSizeType_to_int(net_msg_ptr->getMessageSize());
264    size *=  MESSAGE_SIZE_MULTIPLIER;
265
266    // Artificially increase the size of broadcast messages
267    if (BROADCAST_SCALING > 1 && net_msg_ptr->getDestination().isBroadcast())
268        size *= BROADCAST_SCALING;
269
270    return size;
271}
272