Throttle.cc revision 9508:dde110931867 
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, Cycles link_latency,
52                   int link_bandwidth_multiplier, int endpoint_bandwidth,
53                   ClockedObject *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, Cycles link_latency,
61                   int link_bandwidth_multiplier, int endpoint_bandwidth,
62                   ClockedObject *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, Cycles link_latency,
71               int link_bandwidth_multiplier, 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
122    string desc = "[Queue to Throttle " + to_string(m_sID) + " " +
123        to_string(m_node) + "]";
124    m_in[m_vnets]->setDescription(desc);
125    m_vnets++;
126}
127
128void
129Throttle::wakeup()
130{
131    // Limits the number of message sent to a limited number of bytes/cycle.
132    assert(getLinkBandwidth() > 0);
133    int bw_remaining = getLinkBandwidth();
134
135    // Give the highest numbered link priority most of the time
136    m_wakeups_wo_switch++;
137    int highest_prio_vnet = m_vnets-1;
138    int lowest_prio_vnet = 0;
139    int counter = 1;
140    bool schedule_wakeup = false;
141
142    // invert priorities to avoid starvation seen in the component network
143    if (m_wakeups_wo_switch > PRIORITY_SWITCH_LIMIT) {
144        m_wakeups_wo_switch = 0;
145        highest_prio_vnet = 0;
146        lowest_prio_vnet = m_vnets-1;
147        counter = -1;
148    }
149
150    for (int vnet = highest_prio_vnet;
151         (vnet * counter) >= (counter * lowest_prio_vnet);
152         vnet -= counter) {
153
154        assert(m_out[vnet] != NULL);
155        assert(m_in[vnet] != NULL);
156        assert(m_units_remaining[vnet] >= 0);
157
158        while (bw_remaining > 0 &&
159            (m_in[vnet]->isReady() || m_units_remaining[vnet] > 0) &&
160            m_out[vnet]->areNSlotsAvailable(1)) {
161
162            // See if we are done transferring the previous message on
163            // this virtual network
164            if (m_units_remaining[vnet] == 0 && m_in[vnet]->isReady()) {
165                // Find the size of the message we are moving
166                MsgPtr msg_ptr = m_in[vnet]->peekMsgPtr();
167                NetworkMessage* net_msg_ptr =
168                    safe_cast<NetworkMessage*>(msg_ptr.get());
169                m_units_remaining[vnet] +=
170                    network_message_to_size(net_msg_ptr);
171
172                DPRINTF(RubyNetwork, "throttle: %d my bw %d bw spent "
173                        "enqueueing net msg %d time: %lld.\n",
174                        m_node, getLinkBandwidth(), m_units_remaining[vnet],
175                        g_system_ptr->curCycle());
176
177                // Move the message
178                m_out[vnet]->enqueue(m_in[vnet]->peekMsgPtr(), m_link_latency);
179                m_in[vnet]->pop();
180
181                // Count the message
182                m_message_counters[net_msg_ptr->getMessageSize()][vnet]++;
183
184                DPRINTF(RubyNetwork, "%s\n", *m_out[vnet]);
185            }
186
187            // Calculate the amount of bandwidth we spent on this message
188            int diff = m_units_remaining[vnet] - bw_remaining;
189            m_units_remaining[vnet] = max(0, diff);
190            bw_remaining = max(0, -diff);
191        }
192
193        if (bw_remaining > 0 &&
194            (m_in[vnet]->isReady() || m_units_remaining[vnet] > 0) &&
195            !m_out[vnet]->areNSlotsAvailable(1)) {
196            DPRINTF(RubyNetwork, "vnet: %d", vnet);
197            // schedule me to wakeup again because I'm waiting for my
198            // output queue to become available
199            schedule_wakeup = true;
200        }
201    }
202
203    // We should only wake up when we use the bandwidth
204    // This is only mostly true
205    // assert(bw_remaining != getLinkBandwidth());
206
207    // Record that we used some or all of the link bandwidth this cycle
208    double ratio = 1.0 - (double(bw_remaining) / double(getLinkBandwidth()));
209
210    // If ratio = 0, we used no bandwidth, if ratio = 1, we used all
211    linkUtilized(ratio);
212
213    if (bw_remaining > 0 && !schedule_wakeup) {
214        // We have extra bandwidth and our output buffer was
215        // available, so we must not have anything else to do until
216        // another message arrives.
217        DPRINTF(RubyNetwork, "%s not scheduled again\n", *this);
218    } else {
219        DPRINTF(RubyNetwork, "%s scheduled again\n", *this);
220
221        // We are out of bandwidth for this cycle, so wakeup next
222        // cycle and continue
223        scheduleEvent(Cycles(1));
224    }
225}
226
227void
228Throttle::printStats(ostream& out) const
229{
230    out << "utilized_percent: " << getUtilization() << endl;
231}
232
233void
234Throttle::clearStats()
235{
236    m_ruby_start = g_system_ptr->curCycle();
237    m_links_utilized = 0.0;
238
239    for (int i = 0; i < m_message_counters.size(); i++) {
240        for (int j = 0; j < m_message_counters[i].size(); j++) {
241            m_message_counters[i][j] = 0;
242        }
243    }
244}
245
246double
247Throttle::getUtilization() const
248{
249    return 100.0 * double(m_links_utilized) /
250        double(g_system_ptr->curCycle()-m_ruby_start);
251}
252
253void
254Throttle::print(ostream& out) const
255{
256    ccprintf(out,  "[%i bw: %i]", m_node, getLinkBandwidth());
257}
258
259int
260network_message_to_size(NetworkMessage* net_msg_ptr)
261{
262    assert(net_msg_ptr != NULL);
263
264    int size = Network::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