PerfectSwitch.cc revision 6891:77451885bb00 
1
2/*
3 * Copyright (c) 1999-2008 Mark D. Hill and David A. Wood
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are
8 * met: redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer;
10 * redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution;
13 * neither the name of the copyright holders nor the names of its
14 * contributors may be used to endorse or promote products derived from
15 * this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30/*
31 * PerfectSwitch.cc
32 *
33 * Description: See PerfectSwitch.hh
34 *
35 * $Id$
36 *
37 */
38
39
40#include "mem/ruby/network/simple/PerfectSwitch.hh"
41#include "mem/ruby/slicc_interface/NetworkMessage.hh"
42#include "mem/ruby/profiler/Profiler.hh"
43#include "mem/ruby/system/System.hh"
44#include "mem/ruby/network/simple/SimpleNetwork.hh"
45#include "mem/gems_common/util.hh"
46#include "mem/ruby/buffers/MessageBuffer.hh"
47#include "mem/protocol/Protocol.hh"
48
49const int PRIORITY_SWITCH_LIMIT = 128;
50
51// Operator for helper class
52bool operator<(const LinkOrder& l1, const LinkOrder& l2) {
53  return (l1.m_value < l2.m_value);
54}
55
56PerfectSwitch::PerfectSwitch(SwitchID sid, SimpleNetwork* network_ptr)
57{
58  m_virtual_networks = network_ptr->getNumberOfVirtualNetworks();
59  m_switch_id = sid;
60  m_round_robin_start = 0;
61  m_network_ptr = network_ptr;
62  m_wakeups_wo_switch = 0;
63}
64
65void PerfectSwitch::addInPort(const Vector<MessageBuffer*>& in)
66{
67  assert(in.size() == m_virtual_networks);
68  NodeID port = m_in.size();
69  m_in.insertAtBottom(in);
70  for (int j = 0; j < m_virtual_networks; j++) {
71    m_in[port][j]->setConsumer(this);
72    string desc = "[Queue from port " +  NodeIDToString(m_switch_id) + " " + NodeIDToString(port) + " " + NodeIDToString(j) + " to PerfectSwitch]";
73    m_in[port][j]->setDescription(desc);
74  }
75}
76
77void PerfectSwitch::addOutPort(const Vector<MessageBuffer*>& out, const NetDest& routing_table_entry)
78{
79  assert(out.size() == m_virtual_networks);
80
81  // Setup link order
82  LinkOrder l;
83  l.m_value = 0;
84  l.m_link = m_out.size();
85  m_link_order.insertAtBottom(l);
86
87  // Add to routing table
88  m_out.insertAtBottom(out);
89  m_routing_table.insertAtBottom(routing_table_entry);
90
91}
92
93void PerfectSwitch::clearRoutingTables()
94{
95  m_routing_table.clear();
96}
97
98void PerfectSwitch::clearBuffers()
99{
100  for(int i=0; i<m_in.size(); i++){
101    for(int vnet=0; vnet < m_virtual_networks; vnet++) {
102      m_in[i][vnet]->clear();
103    }
104  }
105
106  for(int i=0; i<m_out.size(); i++){
107    for(int vnet=0; vnet < m_virtual_networks; vnet++) {
108      m_out[i][vnet]->clear();
109    }
110  }
111}
112
113void PerfectSwitch::reconfigureOutPort(const NetDest& routing_table_entry)
114{
115  m_routing_table.insertAtBottom(routing_table_entry);
116}
117
118PerfectSwitch::~PerfectSwitch()
119{
120}
121
122void PerfectSwitch::wakeup()
123{
124
125  DEBUG_EXPR(NETWORK_COMP, MedPrio, m_switch_id);
126
127  MsgPtr msg_ptr;
128
129  // Give the highest numbered link priority most of the time
130  m_wakeups_wo_switch++;
131  int highest_prio_vnet = m_virtual_networks-1;
132  int lowest_prio_vnet = 0;
133  int decrementer = 1;
134  NetworkMessage* net_msg_ptr = NULL;
135
136  // invert priorities to avoid starvation seen in the component network
137  if (m_wakeups_wo_switch > PRIORITY_SWITCH_LIMIT) {
138    m_wakeups_wo_switch = 0;
139    highest_prio_vnet = 0;
140    lowest_prio_vnet = m_virtual_networks-1;
141    decrementer = -1;
142  }
143
144  for (int vnet = highest_prio_vnet; (vnet*decrementer) >= (decrementer*lowest_prio_vnet); vnet -= decrementer) {
145
146    // For all components incoming queues
147    int incoming = m_round_robin_start; // This is for round-robin scheduling
148    m_round_robin_start++;
149    if (m_round_robin_start >= m_in.size()) {
150      m_round_robin_start = 0;
151    }
152
153    // for all input ports, use round robin scheduling
154    for (int counter = 0; counter < m_in.size(); counter++) {
155
156      // Round robin scheduling
157      incoming++;
158      if (incoming >= m_in.size()) {
159        incoming = 0;
160      }
161
162      // temporary vectors to store the routing results
163      Vector<LinkID> output_links;
164      Vector<NetDest> output_link_destinations;
165
166      // Is there a message waiting?
167      while (m_in[incoming][vnet]->isReady()) {
168
169        DEBUG_EXPR(NETWORK_COMP, MedPrio, incoming);
170
171        // Peek at message
172        msg_ptr = m_in[incoming][vnet]->peekMsgPtr();
173        net_msg_ptr = dynamic_cast<NetworkMessage*>(msg_ptr.ref());
174        DEBUG_EXPR(NETWORK_COMP, MedPrio, *net_msg_ptr);
175
176        output_links.clear();
177        output_link_destinations.clear();
178        NetDest msg_destinations = net_msg_ptr->getInternalDestination();
179
180        // Unfortunately, the token-protocol sends some
181        // zero-destination messages, so this assert isn't valid
182        // assert(msg_destinations.count() > 0);
183
184        assert(m_link_order.size() == m_routing_table.size());
185        assert(m_link_order.size() == m_out.size());
186
187        if (m_network_ptr->getAdaptiveRouting()) {
188          if (m_network_ptr->isVNetOrdered(vnet)) {
189            // Don't adaptively route
190            for (int outlink=0; outlink<m_out.size(); outlink++) {
191              m_link_order[outlink].m_link = outlink;
192              m_link_order[outlink].m_value = 0;
193            }
194          } else {
195            // Find how clogged each link is
196            for (int outlink=0; outlink<m_out.size(); outlink++) {
197              int out_queue_length = 0;
198              for (int v=0; v<m_virtual_networks; v++) {
199                out_queue_length += m_out[outlink][v]->getSize();
200              }
201              m_link_order[outlink].m_link = outlink;
202              m_link_order[outlink].m_value = 0;
203              m_link_order[outlink].m_value |= (out_queue_length << 8);
204              m_link_order[outlink].m_value |= (random() & 0xff);
205            }
206            m_link_order.sortVector();  // Look at the most empty link first
207          }
208        }
209
210        for (int i=0; i<m_routing_table.size(); i++) {
211          // pick the next link to look at
212          int link = m_link_order[i].m_link;
213
214          DEBUG_EXPR(NETWORK_COMP, MedPrio, m_routing_table[link]);
215
216          if (msg_destinations.intersectionIsNotEmpty(m_routing_table[link])) {
217
218            // Remember what link we're using
219            output_links.insertAtBottom(link);
220
221            // Need to remember which destinations need this message
222            // in another vector.  This Set is the intersection of the
223            // routing_table entry and the current destination set.
224            // The intersection must not be empty, since we are inside "if"
225            output_link_destinations.insertAtBottom(msg_destinations.AND(m_routing_table[link]));
226
227            // Next, we update the msg_destination not to include
228            // those nodes that were already handled by this link
229            msg_destinations.removeNetDest(m_routing_table[link]);
230          }
231        }
232
233        assert(msg_destinations.count() == 0);
234        //assert(output_links.size() > 0);
235
236        // Check for resources - for all outgoing queues
237        bool enough = true;
238        for (int i=0; i<output_links.size(); i++) {
239          int outgoing = output_links[i];
240          enough = enough && m_out[outgoing][vnet]->areNSlotsAvailable(1);
241          DEBUG_MSG(NETWORK_COMP, HighPrio, "checking if node is blocked");
242          DEBUG_EXPR(NETWORK_COMP, HighPrio, outgoing);
243          DEBUG_EXPR(NETWORK_COMP, HighPrio, vnet);
244          DEBUG_EXPR(NETWORK_COMP, HighPrio, enough);
245        }
246
247        // There were not enough resources
248        if(!enough) {
249          g_eventQueue_ptr->scheduleEvent(this, 1);
250          DEBUG_MSG(NETWORK_COMP, HighPrio, "Can't deliver message to anyone since a node is blocked");
251          DEBUG_EXPR(NETWORK_COMP, HighPrio, *net_msg_ptr);
252          break; // go to next incoming port
253        }
254
255       MsgPtr unmodified_msg_ptr;
256
257        if (output_links.size() > 1) {
258          // If we are sending this message down more than one link
259          // (size>1), we need to make a copy of the message so each
260          // branch can have a different internal destination
261          // we need to create an unmodified MsgPtr because the MessageBuffer enqueue func
262          // will modify the message
263          unmodified_msg_ptr = *(msg_ptr.ref());  // This magic line creates a private copy of the message
264        }
265
266        // Enqueue it - for all outgoing queues
267        for (int i=0; i<output_links.size(); i++) {
268          int outgoing = output_links[i];
269
270          if (i > 0) {
271            msg_ptr = *(unmodified_msg_ptr.ref());  // create a private copy of the unmodified message
272          }
273
274          // Change the internal destination set of the message so it
275          // knows which destinations this link is responsible for.
276          net_msg_ptr = dynamic_cast<NetworkMessage*>(msg_ptr.ref());
277          net_msg_ptr->getInternalDestination() = output_link_destinations[i];
278
279          // Enqeue msg
280          DEBUG_NEWLINE(NETWORK_COMP,HighPrio);
281          DEBUG_MSG(NETWORK_COMP,HighPrio,"switch: " + int_to_string(m_switch_id)
282                    + " enqueuing net msg from inport[" + int_to_string(incoming) + "]["
283                    + int_to_string(vnet) +"] to outport [" + int_to_string(outgoing)
284                    + "][" + int_to_string(vnet) +"]"
285                    + " time: " + int_to_string(g_eventQueue_ptr->getTime()) + ".");
286          DEBUG_NEWLINE(NETWORK_COMP,HighPrio);
287
288          m_out[outgoing][vnet]->enqueue(msg_ptr);
289        }
290
291        // Dequeue msg
292        m_in[incoming][vnet]->pop();
293      }
294    }
295  }
296}
297
298void PerfectSwitch::printStats(ostream& out) const
299{
300  out << "PerfectSwitch printStats" << endl;
301}
302
303void PerfectSwitch::clearStats()
304{
305}
306
307void PerfectSwitch::printConfig(ostream& out) const
308{
309}
310
311void PerfectSwitch::print(ostream& out) const
312{
313  out << "[PerfectSwitch " << m_switch_id << "]";
314}
315
316