Throttle.cc revision 10311:ad9c042dce54 
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    assert(link_bandwidth_multiplier > 0);
73    m_link_bandwidth_multiplier = link_bandwidth_multiplier;
74
75    m_link_latency = link_latency;
76    m_endpoint_bandwidth = endpoint_bandwidth;
77
78    m_wakeups_wo_switch = 0;
79    m_link_utilization_proxy = 0;
80}
81
82void
83Throttle::addLinks(const map<int, MessageBuffer*>& in_vec,
84                   const map<int, MessageBuffer*>& out_vec)
85{
86    assert(in_vec.size() == out_vec.size());
87
88    for (auto& it : in_vec) {
89        int vnet = it.first;
90
91        auto jt = out_vec.find(vnet);
92        assert(jt != out_vec.end());
93
94        MessageBuffer *in_ptr = it.second;
95        MessageBuffer *out_ptr = (*jt).second;
96
97        m_in[vnet] = in_ptr;
98        m_out[vnet] = out_ptr;
99        m_units_remaining[vnet] = 0;
100
101        // Set consumer and description
102        in_ptr->setConsumer(this);
103        string desc = "[Queue to Throttle " + to_string(m_sID) + " " +
104            to_string(m_node) + "]";
105        in_ptr->setDescription(desc);
106    }
107}
108
109void
110Throttle::operateVnet(int vnet, int &bw_remaining, bool &schedule_wakeup,
111                      MessageBuffer *in, MessageBuffer *out)
112{
113    assert(out != NULL);
114    assert(in != NULL);
115    assert(m_units_remaining[vnet] >= 0);
116
117    while (bw_remaining > 0 && (in->isReady() || m_units_remaining[vnet] > 0) &&
118                                out->areNSlotsAvailable(1)) {
119
120        // See if we are done transferring the previous message on
121        // this virtual network
122        if (m_units_remaining[vnet] == 0 && in->isReady()) {
123            // Find the size of the message we are moving
124            MsgPtr msg_ptr = in->peekMsgPtr();
125            NetworkMessage* net_msg_ptr =
126                safe_cast<NetworkMessage*>(msg_ptr.get());
127            m_units_remaining[vnet] +=
128                network_message_to_size(net_msg_ptr);
129
130            DPRINTF(RubyNetwork, "throttle: %d my bw %d bw spent "
131                    "enqueueing net msg %d time: %lld.\n",
132                    m_node, getLinkBandwidth(), m_units_remaining[vnet],
133                    g_system_ptr->curCycle());
134
135            // Move the message
136            in->dequeue();
137            out->enqueue(msg_ptr, m_link_latency);
138
139            // Count the message
140            m_msg_counts[net_msg_ptr->getMessageSize()][vnet]++;
141            DPRINTF(RubyNetwork, "%s\n", *out);
142        }
143
144        // Calculate the amount of bandwidth we spent on this message
145        int diff = m_units_remaining[vnet] - bw_remaining;
146        m_units_remaining[vnet] = max(0, diff);
147        bw_remaining = max(0, -diff);
148    }
149
150    if (bw_remaining > 0 && (in->isReady() || m_units_remaining[vnet] > 0) &&
151                             !out->areNSlotsAvailable(1)) {
152        DPRINTF(RubyNetwork, "vnet: %d", vnet);
153
154        // schedule me to wakeup again because I'm waiting for my
155        // output queue to become available
156        schedule_wakeup = true;
157    }
158}
159
160void
161Throttle::wakeup()
162{
163    // Limits the number of message sent to a limited number of bytes/cycle.
164    assert(getLinkBandwidth() > 0);
165    int bw_remaining = getLinkBandwidth();
166
167    m_wakeups_wo_switch++;
168    bool schedule_wakeup = false;
169
170    // variable for deciding the direction in which to iterate
171    bool iteration_direction = false;
172
173
174    // invert priorities to avoid starvation seen in the component network
175    if (m_wakeups_wo_switch > PRIORITY_SWITCH_LIMIT) {
176        m_wakeups_wo_switch = 0;
177        iteration_direction = true;
178    }
179
180    if (iteration_direction) {
181        for (auto& it : m_in) {
182            int vnet = it.first;
183            operateVnet(vnet, bw_remaining, schedule_wakeup,
184                        it.second, m_out[vnet]);
185        }
186    } else {
187        for (auto it = m_in.rbegin(); it != m_in.rend(); ++it) {
188            int vnet = (*it).first;
189            operateVnet(vnet, bw_remaining, schedule_wakeup,
190                        (*it).second, m_out[vnet]);
191        }
192    }
193
194    // We should only wake up when we use the bandwidth
195    // This is only mostly true
196    // assert(bw_remaining != getLinkBandwidth());
197
198    // Record that we used some or all of the link bandwidth this cycle
199    double ratio = 1.0 - (double(bw_remaining) / double(getLinkBandwidth()));
200
201    // If ratio = 0, we used no bandwidth, if ratio = 1, we used all
202    m_link_utilization_proxy += ratio;
203
204    if (bw_remaining > 0 && !schedule_wakeup) {
205        // We have extra bandwidth and our output buffer was
206        // available, so we must not have anything else to do until
207        // another message arrives.
208        DPRINTF(RubyNetwork, "%s not scheduled again\n", *this);
209    } else {
210        DPRINTF(RubyNetwork, "%s scheduled again\n", *this);
211
212        // We are out of bandwidth for this cycle, so wakeup next
213        // cycle and continue
214        scheduleEvent(Cycles(1));
215    }
216}
217
218void
219Throttle::regStats(string parent)
220{
221    m_link_utilization
222        .name(parent + csprintf(".throttle%i", m_node) + ".link_utilization");
223
224    for (MessageSizeType type = MessageSizeType_FIRST;
225         type < MessageSizeType_NUM; ++type) {
226        m_msg_counts[(unsigned int)type]
227            .init(Network::getNumberOfVirtualNetworks())
228            .name(parent + csprintf(".throttle%i", m_node) + ".msg_count." +
229                    MessageSizeType_to_string(type))
230            .flags(Stats::nozero)
231            ;
232        m_msg_bytes[(unsigned int) type]
233            .name(parent + csprintf(".throttle%i", m_node) + ".msg_bytes." +
234                    MessageSizeType_to_string(type))
235            .flags(Stats::nozero)
236            ;
237
238        m_msg_bytes[(unsigned int) type] = m_msg_counts[type] * Stats::constant(
239                Network::MessageSizeType_to_int(type));
240    }
241}
242
243void
244Throttle::clearStats()
245{
246    m_link_utilization_proxy = 0;
247}
248
249void
250Throttle::collateStats()
251{
252    m_link_utilization = 100.0 * m_link_utilization_proxy
253        / (double(g_system_ptr->curCycle() - g_ruby_start));
254}
255
256void
257Throttle::print(ostream& out) const
258{
259    ccprintf(out,  "[%i bw: %i]", m_node, getLinkBandwidth());
260}
261
262int
263network_message_to_size(NetworkMessage* net_msg_ptr)
264{
265    assert(net_msg_ptr != NULL);
266
267    int size = Network::MessageSizeType_to_int(net_msg_ptr->getMessageSize());
268    size *=  MESSAGE_SIZE_MULTIPLIER;
269
270    // Artificially increase the size of broadcast messages
271    if (BROADCAST_SCALING > 1 && net_msg_ptr->getDestination().isBroadcast())
272        size *= BROADCAST_SCALING;
273
274    return size;
275}
276