Throttle.cc revision 7780 
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
37using namespace std;
38
39const int HIGH_RANGE = 256;
40const int ADJUST_INTERVAL = 50000;
41const int MESSAGE_SIZE_MULTIPLIER = 1000;
42//const int BROADCAST_SCALING = 4; // Have a 16p system act like a 64p systems
43const int BROADCAST_SCALING = 1;
44const int PRIORITY_SWITCH_LIMIT = 128;
45
46static int network_message_to_size(NetworkMessage* net_msg_ptr);
47
48extern ostream *debug_cout_ptr;
49
50Throttle::Throttle(int sID, NodeID node, int link_latency,
51    int link_bandwidth_multiplier)
52{
53    init(node, link_latency, link_bandwidth_multiplier);
54    m_sID = sID;
55}
56
57Throttle::Throttle(NodeID node, int link_latency,
58    int link_bandwidth_multiplier)
59{
60    init(node, link_latency, link_bandwidth_multiplier);
61    m_sID = 0;
62}
63
64void
65Throttle::init(NodeID node, int link_latency, int link_bandwidth_multiplier)
66{
67    m_node = node;
68    m_vnets = 0;
69
70    ASSERT(link_bandwidth_multiplier > 0);
71    m_link_bandwidth_multiplier = link_bandwidth_multiplier;
72    m_link_latency = link_latency;
73
74    m_wakeups_wo_switch = 0;
75    clearStats();
76}
77
78void
79Throttle::clear()
80{
81    for (int counter = 0; counter < m_vnets; counter++) {
82        m_in[counter]->clear();
83        m_out[counter]->clear();
84    }
85}
86
87void
88Throttle::addLinks(const std::vector<MessageBuffer*>& in_vec,
89    const std::vector<MessageBuffer*>& out_vec)
90{
91    assert(in_vec.size() == out_vec.size());
92    for (int i=0; i<in_vec.size(); i++) {
93        addVirtualNetwork(in_vec[i], out_vec[i]);
94    }
95
96    m_message_counters.resize(MessageSizeType_NUM);
97    for (int i = 0; i < MessageSizeType_NUM; i++) {
98        m_message_counters[i].resize(in_vec.size());
99        for (int j = 0; j<m_message_counters[i].size(); j++) {
100            m_message_counters[i][j] = 0;
101        }
102    }
103}
104
105void
106Throttle::addVirtualNetwork(MessageBuffer* in_ptr, MessageBuffer* out_ptr)
107{
108    m_units_remaining.push_back(0);
109    m_in.push_back(in_ptr);
110    m_out.push_back(out_ptr);
111
112    // Set consumer and description
113    m_in[m_vnets]->setConsumer(this);
114    string desc = "[Queue to Throttle " + NodeIDToString(m_sID) + " " +
115        NodeIDToString(m_node) + "]";
116    m_in[m_vnets]->setDescription(desc);
117    m_vnets++;
118}
119
120void
121Throttle::wakeup()
122{
123    // Limits the number of message sent to a limited number of bytes/cycle.
124    assert(getLinkBandwidth() > 0);
125    int bw_remaining = getLinkBandwidth();
126
127    // Give the highest numbered link priority most of the time
128    m_wakeups_wo_switch++;
129    int highest_prio_vnet = m_vnets-1;
130    int lowest_prio_vnet = 0;
131    int counter = 1;
132    bool schedule_wakeup = false;
133
134    // invert priorities to avoid starvation seen in the component network
135    if (m_wakeups_wo_switch > PRIORITY_SWITCH_LIMIT) {
136        m_wakeups_wo_switch = 0;
137        highest_prio_vnet = 0;
138        lowest_prio_vnet = m_vnets-1;
139        counter = -1;
140    }
141
142    for (int vnet = highest_prio_vnet;
143         (vnet * counter) >= (counter * lowest_prio_vnet);
144         vnet -= counter) {
145
146        assert(m_out[vnet] != NULL);
147        assert(m_in[vnet] != NULL);
148        assert(m_units_remaining[vnet] >= 0);
149
150        while (bw_remaining > 0 &&
151            (m_in[vnet]->isReady() || m_units_remaining[vnet] > 0) &&
152            m_out[vnet]->areNSlotsAvailable(1)) {
153
154            // See if we are done transferring the previous message on
155            // this virtual network
156            if (m_units_remaining[vnet] == 0 && m_in[vnet]->isReady()) {
157                // Find the size of the message we are moving
158                MsgPtr msg_ptr = m_in[vnet]->peekMsgPtr();
159                NetworkMessage* net_msg_ptr =
160                    safe_cast<NetworkMessage*>(msg_ptr.get());
161                m_units_remaining[vnet] +=
162                    network_message_to_size(net_msg_ptr);
163
164                DPRINTF(RubyNetwork, "throttle: %d my bw %d bw spent "
165                        "enqueueing net msg %d time: %lld.\n",
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                DPRINTF(RubyNetwork, "%s\n", *m_out[vnet]);
177            }
178
179            // Calculate the amount of bandwidth we spent on this message
180            int diff = m_units_remaining[vnet] - bw_remaining;
181            m_units_remaining[vnet] = max(0, diff);
182            bw_remaining = max(0, -diff);
183        }
184
185        if (bw_remaining > 0 &&
186            (m_in[vnet]->isReady() || m_units_remaining[vnet] > 0) &&
187            !m_out[vnet]->areNSlotsAvailable(1)) {
188            DPRINTF(RubyNetwork, "vnet: %d", vnet);
189            // schedule me to wakeup again because I'm waiting for my
190            // output queue to become available
191            schedule_wakeup = true;
192        }
193    }
194
195    // We should only wake up when we use the bandwidth
196    // This is only mostly true
197    // assert(bw_remaining != getLinkBandwidth());
198
199    // Record that we used some or all of the link bandwidth this cycle
200    double ratio = 1.0 - (double(bw_remaining) / double(getLinkBandwidth()));
201
202    // If ratio = 0, we used no bandwidth, if ratio = 1, we used all
203    linkUtilized(ratio);
204
205    if (bw_remaining > 0 && !schedule_wakeup) {
206        // We have extra bandwidth and our output buffer was
207        // available, so we must not have anything else to do until
208        // another message arrives.
209        DPRINTF(RubyNetwork, "%s not scheduled again\n", *this);
210    } else {
211        DPRINTF(RubyNetwork, "%s scheduled again\n", *this);
212
213        // We are out of bandwidth for this cycle, so wakeup next
214        // cycle and continue
215        g_eventQueue_ptr->scheduleEvent(this, 1);
216    }
217}
218
219void
220Throttle::printStats(ostream& out) const
221{
222    out << "utilized_percent: " << getUtilization() << endl;
223}
224
225void
226Throttle::clearStats()
227{
228    m_ruby_start = g_eventQueue_ptr->getTime();
229    m_links_utilized = 0.0;
230
231    for (int i = 0; i < m_message_counters.size(); i++) {
232        for (int j = 0; j < m_message_counters[i].size(); j++) {
233            m_message_counters[i][j] = 0;
234        }
235    }
236}
237
238void
239Throttle::printConfig(ostream& out) const
240{
241}
242
243double
244Throttle::getUtilization() const
245{
246    return 100.0 * double(m_links_utilized) /
247        double(g_eventQueue_ptr->getTime()-m_ruby_start);
248}
249
250void
251Throttle::print(ostream& out) const
252{
253    out << "[Throttle: " << m_sID << " " << m_node
254        << " bw: " << 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