Throttle.cc revision 11021:e8a6637afa4c 
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/Message.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(Message* net_msg_ptr);
48
49Throttle::Throttle(int sID, RubySystem *rs, NodeID node, Cycles link_latency,
50                   int link_bandwidth_multiplier, int endpoint_bandwidth,
51                   ClockedObject *em)
52    : Consumer(em), m_ruby_system(rs)
53{
54    init(node, link_latency, link_bandwidth_multiplier, endpoint_bandwidth);
55    m_sID = sID;
56}
57
58Throttle::Throttle(RubySystem *rs, NodeID node, Cycles link_latency,
59                   int link_bandwidth_multiplier, int endpoint_bandwidth,
60                   ClockedObject *em)
61    : Consumer(em), m_ruby_system(rs)
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    }
104}
105
106void
107Throttle::operateVnet(int vnet, int &bw_remaining, bool &schedule_wakeup,
108                      MessageBuffer *in, MessageBuffer *out)
109{
110    if (out == nullptr || in == nullptr) {
111        return;
112    }
113    assert(m_units_remaining[vnet] >= 0);
114
115    while (bw_remaining > 0 && (in->isReady() || m_units_remaining[vnet] > 0) &&
116                                out->areNSlotsAvailable(1)) {
117
118        // See if we are done transferring the previous message on
119        // this virtual network
120        if (m_units_remaining[vnet] == 0 && in->isReady()) {
121            // Find the size of the message we are moving
122            MsgPtr msg_ptr = in->peekMsgPtr();
123            Message *net_msg_ptr = msg_ptr.get();
124            m_units_remaining[vnet] +=
125                network_message_to_size(net_msg_ptr);
126
127            DPRINTF(RubyNetwork, "throttle: %d my bw %d bw spent "
128                    "enqueueing net msg %d time: %lld.\n",
129                    m_node, getLinkBandwidth(), m_units_remaining[vnet],
130                    m_ruby_system->curCycle());
131
132            // Move the message
133            in->dequeue();
134            out->enqueue(msg_ptr, m_link_latency);
135
136            // Count the message
137            m_msg_counts[net_msg_ptr->getMessageSize()][vnet]++;
138            DPRINTF(RubyNetwork, "%s\n", *out);
139        }
140
141        // Calculate the amount of bandwidth we spent on this message
142        int diff = m_units_remaining[vnet] - bw_remaining;
143        m_units_remaining[vnet] = max(0, diff);
144        bw_remaining = max(0, -diff);
145    }
146
147    if (bw_remaining > 0 && (in->isReady() || m_units_remaining[vnet] > 0) &&
148                             !out->areNSlotsAvailable(1)) {
149        DPRINTF(RubyNetwork, "vnet: %d", vnet);
150
151        // schedule me to wakeup again because I'm waiting for my
152        // output queue to become available
153        schedule_wakeup = true;
154    }
155}
156
157void
158Throttle::wakeup()
159{
160    // Limits the number of message sent to a limited number of bytes/cycle.
161    assert(getLinkBandwidth() > 0);
162    int bw_remaining = getLinkBandwidth();
163
164    m_wakeups_wo_switch++;
165    bool schedule_wakeup = false;
166
167    // variable for deciding the direction in which to iterate
168    bool iteration_direction = false;
169
170
171    // invert priorities to avoid starvation seen in the component network
172    if (m_wakeups_wo_switch > PRIORITY_SWITCH_LIMIT) {
173        m_wakeups_wo_switch = 0;
174        iteration_direction = true;
175    }
176
177    if (iteration_direction) {
178        for (int vnet = 0; vnet < m_vnets; ++vnet) {
179            operateVnet(vnet, bw_remaining, schedule_wakeup,
180                        m_in[vnet], m_out[vnet]);
181        }
182    } else {
183        for (int vnet = m_vnets-1; vnet >= 0; --vnet) {
184            operateVnet(vnet, bw_remaining, schedule_wakeup,
185                        m_in[vnet], m_out[vnet]);
186        }
187    }
188
189    // We should only wake up when we use the bandwidth
190    // This is only mostly true
191    // assert(bw_remaining != getLinkBandwidth());
192
193    // Record that we used some or all of the link bandwidth this cycle
194    double ratio = 1.0 - (double(bw_remaining) / double(getLinkBandwidth()));
195
196    // If ratio = 0, we used no bandwidth, if ratio = 1, we used all
197    m_link_utilization_proxy += ratio;
198
199    if (bw_remaining > 0 && !schedule_wakeup) {
200        // We have extra bandwidth and our output buffer was
201        // available, so we must not have anything else to do until
202        // another message arrives.
203        DPRINTF(RubyNetwork, "%s not scheduled again\n", *this);
204    } else {
205        DPRINTF(RubyNetwork, "%s scheduled again\n", *this);
206
207        // We are out of bandwidth for this cycle, so wakeup next
208        // cycle and continue
209        scheduleEvent(Cycles(1));
210    }
211}
212
213void
214Throttle::regStats(string parent)
215{
216    m_link_utilization
217        .name(parent + csprintf(".throttle%i", m_node) + ".link_utilization");
218
219    for (MessageSizeType type = MessageSizeType_FIRST;
220         type < MessageSizeType_NUM; ++type) {
221        m_msg_counts[(unsigned int)type]
222            .init(Network::getNumberOfVirtualNetworks())
223            .name(parent + csprintf(".throttle%i", m_node) + ".msg_count." +
224                    MessageSizeType_to_string(type))
225            .flags(Stats::nozero)
226            ;
227        m_msg_bytes[(unsigned int) type]
228            .name(parent + csprintf(".throttle%i", m_node) + ".msg_bytes." +
229                    MessageSizeType_to_string(type))
230            .flags(Stats::nozero)
231            ;
232
233        m_msg_bytes[(unsigned int) type] = m_msg_counts[type] * Stats::constant(
234                Network::MessageSizeType_to_int(type));
235    }
236}
237
238void
239Throttle::clearStats()
240{
241    m_link_utilization_proxy = 0;
242}
243
244void
245Throttle::collateStats()
246{
247    double time_delta = double(m_ruby_system->curCycle() -
248                               m_ruby_system->getStartCycle());
249
250    m_link_utilization = 100.0 * m_link_utilization_proxy / time_delta;
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(Message *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