Throttle.cc revision 8232 
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/protocol/Protocol.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)
53{
54    init(node, link_latency, link_bandwidth_multiplier);
55    m_sID = sID;
56}
57
58Throttle::Throttle(NodeID node, int link_latency,
59    int link_bandwidth_multiplier)
60{
61    init(node, link_latency, link_bandwidth_multiplier);
62    m_sID = 0;
63}
64
65void
66Throttle::init(NodeID node, int link_latency, int link_bandwidth_multiplier)
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
75    m_wakeups_wo_switch = 0;
76    clearStats();
77}
78
79void
80Throttle::clear()
81{
82    for (int counter = 0; counter < m_vnets; counter++) {
83        m_in[counter]->clear();
84        m_out[counter]->clear();
85    }
86}
87
88void
89Throttle::addLinks(const std::vector<MessageBuffer*>& in_vec,
90    const std::vector<MessageBuffer*>& out_vec)
91{
92    assert(in_vec.size() == out_vec.size());
93    for (int i=0; i<in_vec.size(); i++) {
94        addVirtualNetwork(in_vec[i], out_vec[i]);
95    }
96
97    m_message_counters.resize(MessageSizeType_NUM);
98    for (int i = 0; i < MessageSizeType_NUM; i++) {
99        m_message_counters[i].resize(in_vec.size());
100        for (int j = 0; j<m_message_counters[i].size(); j++) {
101            m_message_counters[i][j] = 0;
102        }
103    }
104}
105
106void
107Throttle::addVirtualNetwork(MessageBuffer* in_ptr, MessageBuffer* out_ptr)
108{
109    m_units_remaining.push_back(0);
110    m_in.push_back(in_ptr);
111    m_out.push_back(out_ptr);
112
113    // Set consumer and description
114    m_in[m_vnets]->setConsumer(this);
115    string desc = "[Queue to Throttle " + NodeIDToString(m_sID) + " " +
116        NodeIDToString(m_node) + "]";
117    m_in[m_vnets]->setDescription(desc);
118    m_vnets++;
119}
120
121void
122Throttle::wakeup()
123{
124    // Limits the number of message sent to a limited number of bytes/cycle.
125    assert(getLinkBandwidth() > 0);
126    int bw_remaining = getLinkBandwidth();
127
128    // Give the highest numbered link priority most of the time
129    m_wakeups_wo_switch++;
130    int highest_prio_vnet = m_vnets-1;
131    int lowest_prio_vnet = 0;
132    int counter = 1;
133    bool schedule_wakeup = false;
134
135    // invert priorities to avoid starvation seen in the component network
136    if (m_wakeups_wo_switch > PRIORITY_SWITCH_LIMIT) {
137        m_wakeups_wo_switch = 0;
138        highest_prio_vnet = 0;
139        lowest_prio_vnet = m_vnets-1;
140        counter = -1;
141    }
142
143    for (int vnet = highest_prio_vnet;
144         (vnet * counter) >= (counter * lowest_prio_vnet);
145         vnet -= counter) {
146
147        assert(m_out[vnet] != NULL);
148        assert(m_in[vnet] != NULL);
149        assert(m_units_remaining[vnet] >= 0);
150
151        while (bw_remaining > 0 &&
152            (m_in[vnet]->isReady() || m_units_remaining[vnet] > 0) &&
153            m_out[vnet]->areNSlotsAvailable(1)) {
154
155            // See if we are done transferring the previous message on
156            // this virtual network
157            if (m_units_remaining[vnet] == 0 && m_in[vnet]->isReady()) {
158                // Find the size of the message we are moving
159                MsgPtr msg_ptr = m_in[vnet]->peekMsgPtr();
160                NetworkMessage* net_msg_ptr =
161                    safe_cast<NetworkMessage*>(msg_ptr.get());
162                m_units_remaining[vnet] +=
163                    network_message_to_size(net_msg_ptr);
164
165                DPRINTF(RubyNetwork, "throttle: %d my bw %d bw spent "
166                        "enqueueing net msg %d time: %lld.\n",
167                        m_node, getLinkBandwidth(), m_units_remaining[vnet],
168                        g_eventQueue_ptr->getTime());
169
170                // Move the message
171                m_out[vnet]->enqueue(m_in[vnet]->peekMsgPtr(), m_link_latency);
172                m_in[vnet]->pop();
173
174                // Count the message
175                m_message_counters[net_msg_ptr->getMessageSize()][vnet]++;
176
177                DPRINTF(RubyNetwork, "%s\n", *m_out[vnet]);
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            DPRINTF(RubyNetwork, "vnet: %d", 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        DPRINTF(RubyNetwork, "%s not scheduled again\n", *this);
211    } else {
212        DPRINTF(RubyNetwork, "%s scheduled again\n", *this);
213
214        // We are out of bandwidth for this cycle, so wakeup next
215        // cycle and continue
216        g_eventQueue_ptr->scheduleEvent(this, 1);
217    }
218}
219
220void
221Throttle::printStats(ostream& out) const
222{
223    out << "utilized_percent: " << getUtilization() << endl;
224}
225
226void
227Throttle::clearStats()
228{
229    m_ruby_start = g_eventQueue_ptr->getTime();
230    m_links_utilized = 0.0;
231
232    for (int i = 0; i < m_message_counters.size(); i++) {
233        for (int j = 0; j < m_message_counters[i].size(); j++) {
234            m_message_counters[i][j] = 0;
235        }
236    }
237}
238
239void
240Throttle::printConfig(ostream& out) const
241{
242}
243
244double
245Throttle::getUtilization() const
246{
247    return 100.0 * double(m_links_utilized) /
248        double(g_eventQueue_ptr->getTime()-m_ruby_start);
249}
250
251void
252Throttle::print(ostream& out) const
253{
254    ccprintf(out,  "[%i bw: %i]", m_node, getLinkBandwidth());
255}
256
257int
258network_message_to_size(NetworkMessage* net_msg_ptr)
259{
260    assert(net_msg_ptr != NULL);
261
262    int size = RubySystem::getNetwork()->
263        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