Throttle.cc revision 10370:4466307b8a2a 
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/network/simple/Throttle.hh"
35#include "mem/ruby/network/MessageBuffer.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 MESSAGE_SIZE_MULTIPLIER = 1000;
43//const int BROADCAST_SCALING = 4; // Have a 16p system act like a 64p systems
44const int BROADCAST_SCALING = 1;
45const int PRIORITY_SWITCH_LIMIT = 128;
46
47static int network_message_to_size(NetworkMessage* net_msg_ptr);
48
49Throttle::Throttle(int sID, NodeID node, Cycles link_latency,
50                   int link_bandwidth_multiplier, int endpoint_bandwidth,
51                   ClockedObject *em)
52    : Consumer(em)
53{
54    init(node, link_latency, link_bandwidth_multiplier, endpoint_bandwidth);
55    m_sID = sID;
56}
57
58Throttle::Throttle(NodeID node, Cycles link_latency,
59                   int link_bandwidth_multiplier, int endpoint_bandwidth,
60                   ClockedObject *em)
61    : Consumer(em)
62{
63    init(node, link_latency, link_bandwidth_multiplier, endpoint_bandwidth);
64    m_sID = 0;
65}
66
67void
68Throttle::init(NodeID node, Cycles link_latency,
69               int link_bandwidth_multiplier, int endpoint_bandwidth)
70{
71    m_node = node;
72    m_vnets = 0;
73
74    assert(link_bandwidth_multiplier > 0);
75    m_link_bandwidth_multiplier = link_bandwidth_multiplier;
76
77    m_link_latency = link_latency;
78    m_endpoint_bandwidth = endpoint_bandwidth;
79
80    m_wakeups_wo_switch = 0;
81    m_link_utilization_proxy = 0;
82}
83
84void
85Throttle::addLinks(const vector<MessageBuffer*>& in_vec,
86                   const vector<MessageBuffer*>& out_vec)
87{
88    assert(in_vec.size() == out_vec.size());
89
90    for (int vnet = 0; vnet < in_vec.size(); ++vnet) {
91        MessageBuffer *in_ptr = in_vec[vnet];
92        MessageBuffer *out_ptr = out_vec[vnet];
93
94        m_vnets++;
95        m_units_remaining.push_back(0);
96        m_in.push_back(in_ptr);
97        m_out.push_back(out_ptr);
98
99        // Set consumer and description
100        in_ptr->setConsumer(this);
101        string desc = "[Queue to Throttle " + to_string(m_sID) + " " +
102            to_string(m_node) + "]";
103        in_ptr->setDescription(desc);
104    }
105}
106
107void
108Throttle::operateVnet(int vnet, int &bw_remaining, bool &schedule_wakeup,
109                      MessageBuffer *in, MessageBuffer *out)
110{
111    if (out == nullptr || in == nullptr) {
112        return;
113    }
114    assert(m_units_remaining[vnet] >= 0);
115
116    while (bw_remaining > 0 && (in->isReady() || m_units_remaining[vnet] > 0) &&
117                                out->areNSlotsAvailable(1)) {
118
119        // See if we are done transferring the previous message on
120        // this virtual network
121        if (m_units_remaining[vnet] == 0 && in->isReady()) {
122            // Find the size of the message we are moving
123            MsgPtr msg_ptr = in->peekMsgPtr();
124            NetworkMessage* net_msg_ptr =
125                safe_cast<NetworkMessage*>(msg_ptr.get());
126            m_units_remaining[vnet] +=
127                network_message_to_size(net_msg_ptr);
128
129            DPRINTF(RubyNetwork, "throttle: %d my bw %d bw spent "
130                    "enqueueing net msg %d time: %lld.\n",
131                    m_node, getLinkBandwidth(), m_units_remaining[vnet],
132                    g_system_ptr->curCycle());
133
134            // Move the message
135            in->dequeue();
136            out->enqueue(msg_ptr, m_link_latency);
137
138            // Count the message
139            m_msg_counts[net_msg_ptr->getMessageSize()][vnet]++;
140            DPRINTF(RubyNetwork, "%s\n", *out);
141        }
142
143        // Calculate the amount of bandwidth we spent on this message
144        int diff = m_units_remaining[vnet] - bw_remaining;
145        m_units_remaining[vnet] = max(0, diff);
146        bw_remaining = max(0, -diff);
147    }
148
149    if (bw_remaining > 0 && (in->isReady() || m_units_remaining[vnet] > 0) &&
150                             !out->areNSlotsAvailable(1)) {
151        DPRINTF(RubyNetwork, "vnet: %d", vnet);
152
153        // schedule me to wakeup again because I'm waiting for my
154        // output queue to become available
155        schedule_wakeup = true;
156    }
157}
158
159void
160Throttle::wakeup()
161{
162    // Limits the number of message sent to a limited number of bytes/cycle.
163    assert(getLinkBandwidth() > 0);
164    int bw_remaining = getLinkBandwidth();
165
166    m_wakeups_wo_switch++;
167    bool schedule_wakeup = false;
168
169    // variable for deciding the direction in which to iterate
170    bool iteration_direction = false;
171
172
173    // invert priorities to avoid starvation seen in the component network
174    if (m_wakeups_wo_switch > PRIORITY_SWITCH_LIMIT) {
175        m_wakeups_wo_switch = 0;
176        iteration_direction = true;
177    }
178
179    if (iteration_direction) {
180        for (int vnet = 0; vnet < m_vnets; ++vnet) {
181            operateVnet(vnet, bw_remaining, schedule_wakeup,
182                        m_in[vnet], m_out[vnet]);
183        }
184    } else {
185        for (int vnet = m_vnets-1; vnet >= 0; --vnet) {
186            operateVnet(vnet, bw_remaining, schedule_wakeup,
187                        m_in[vnet], m_out[vnet]);
188        }
189    }
190
191    // We should only wake up when we use the bandwidth
192    // This is only mostly true
193    // assert(bw_remaining != getLinkBandwidth());
194
195    // Record that we used some or all of the link bandwidth this cycle
196    double ratio = 1.0 - (double(bw_remaining) / double(getLinkBandwidth()));
197
198    // If ratio = 0, we used no bandwidth, if ratio = 1, we used all
199    m_link_utilization_proxy += ratio;
200
201    if (bw_remaining > 0 && !schedule_wakeup) {
202        // We have extra bandwidth and our output buffer was
203        // available, so we must not have anything else to do until
204        // another message arrives.
205        DPRINTF(RubyNetwork, "%s not scheduled again\n", *this);
206    } else {
207        DPRINTF(RubyNetwork, "%s scheduled again\n", *this);
208
209        // We are out of bandwidth for this cycle, so wakeup next
210        // cycle and continue
211        scheduleEvent(Cycles(1));
212    }
213}
214
215void
216Throttle::regStats(string parent)
217{
218    m_link_utilization
219        .name(parent + csprintf(".throttle%i", m_node) + ".link_utilization");
220
221    for (MessageSizeType type = MessageSizeType_FIRST;
222         type < MessageSizeType_NUM; ++type) {
223        m_msg_counts[(unsigned int)type]
224            .init(Network::getNumberOfVirtualNetworks())
225            .name(parent + csprintf(".throttle%i", m_node) + ".msg_count." +
226                    MessageSizeType_to_string(type))
227            .flags(Stats::nozero)
228            ;
229        m_msg_bytes[(unsigned int) type]
230            .name(parent + csprintf(".throttle%i", m_node) + ".msg_bytes." +
231                    MessageSizeType_to_string(type))
232            .flags(Stats::nozero)
233            ;
234
235        m_msg_bytes[(unsigned int) type] = m_msg_counts[type] * Stats::constant(
236                Network::MessageSizeType_to_int(type));
237    }
238}
239
240void
241Throttle::clearStats()
242{
243    m_link_utilization_proxy = 0;
244}
245
246void
247Throttle::collateStats()
248{
249    m_link_utilization = 100.0 * m_link_utilization_proxy
250        / (double(g_system_ptr->curCycle() - g_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