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 "mem/ruby/network/MessageBuffer.hh"
30
31#include <cassert>
32
33#include "base/cprintf.hh"
34#include "base/misc.hh"
35#include "base/random.hh"
36#include "base/stl_helpers.hh"
37#include "debug/RubyQueue.hh"
38#include "mem/ruby/system/RubySystem.hh"
39
40using namespace std;
41using m5::stl_helpers::operator<<;
42
43MessageBuffer::MessageBuffer(const Params *p)
44 : SimObject(p), m_stall_map_size(0),
45 m_max_size(p->buffer_size), m_time_last_time_size_checked(0),
46 m_time_last_time_enqueue(0), m_time_last_time_pop(0),
47 m_last_arrival_time(0), m_strict_fifo(p->ordered),
48 m_randomization(p->randomization)
49{
50 m_msg_counter = 0;
51 m_consumer = NULL;
52 m_size_last_time_size_checked = 0;
53 m_size_at_cycle_start = 0;
54 m_msgs_this_cycle = 0;
55 m_priority_rank = 0;
56
57 m_stall_msg_map.clear();
58 m_input_link_id = 0;
59 m_vnet_id = 0;
60
61 m_buf_msgs = 0;
62 m_stall_time = 0;
63}
64
65unsigned int
66MessageBuffer::getSize(Tick curTime)
67{
68 if (m_time_last_time_size_checked != curTime) {
69 m_time_last_time_size_checked = curTime;
70 m_size_last_time_size_checked = m_prio_heap.size();
71 }
72
73 return m_size_last_time_size_checked;
74}
75
76bool
77MessageBuffer::areNSlotsAvailable(unsigned int n, Tick current_time)
78{
79
80 // fast path when message buffers have infinite size
81 if (m_max_size == 0) {
82 return true;
83 }
84
85 // determine the correct size for the current cycle
86 // pop operations shouldn't effect the network's visible size
87 // until schd cycle, but enqueue operations effect the visible
88 // size immediately
89 unsigned int current_size = 0;
90
91 if (m_time_last_time_pop < current_time) {
92 // no pops this cycle - heap size is correct
93 current_size = m_prio_heap.size();
94 } else {
95 if (m_time_last_time_enqueue < current_time) {
96 // no enqueues this cycle - m_size_at_cycle_start is correct
97 current_size = m_size_at_cycle_start;
98 } else {
99 // both pops and enqueues occured this cycle - add new
100 // enqueued msgs to m_size_at_cycle_start
101 current_size = m_size_at_cycle_start + m_msgs_this_cycle;
102 }
103 }
104
105 // now compare the new size with our max size
106 if (current_size + m_stall_map_size + n <= m_max_size) {
107 return true;
108 } else {
109 DPRINTF(RubyQueue, "n: %d, current_size: %d, heap size: %d, "
110 "m_max_size: %d\n",
111 n, current_size, m_prio_heap.size(), m_max_size);
112 m_not_avail_count++;
113 return false;
114 }
115}
116
117const Message*
118MessageBuffer::peek() const
119{
120 DPRINTF(RubyQueue, "Peeking at head of queue.\n");
121 const Message* msg_ptr = m_prio_heap.front().get();
122 assert(msg_ptr);
123
124 DPRINTF(RubyQueue, "Message: %s\n", (*msg_ptr));
125 return msg_ptr;
126}
127
128// FIXME - move me somewhere else
129Tick
130random_time()
131{
132 Tick time = 1;
133 time += random_mt.random(0, 3); // [0...3]
134 if (random_mt.random(0, 7) == 0) { // 1 in 8 chance
135 time += 100 + random_mt.random(1, 15); // 100 + [1...15]
136 }
137 return time;
138}
139
140void
141MessageBuffer::enqueue(MsgPtr message, Tick current_time, Tick delta)
142{
143 // record current time incase we have a pop that also adjusts my size
144 if (m_time_last_time_enqueue < current_time) {
145 m_msgs_this_cycle = 0; // first msg this cycle
146 m_time_last_time_enqueue = current_time;
147 }
148
149 m_msg_counter++;
150 m_msgs_this_cycle++;
151
152 // Calculate the arrival time of the message, that is, the first
153 // cycle the message can be dequeued.
154 assert(delta > 0);
155 Tick arrival_time = 0;
156
157 if (!RubySystem::getRandomization() || !m_randomization) {
158 // No randomization
159 arrival_time = current_time + delta;
160 } else {
161 // Randomization - ignore delta
162 if (m_strict_fifo) {
163 if (m_last_arrival_time < current_time) {
164 m_last_arrival_time = current_time;
165 }
166 arrival_time = m_last_arrival_time + random_time();
167 } else {
168 arrival_time = current_time + random_time();
169 }
170 }
171
172 // Check the arrival time
173 assert(arrival_time > current_time);
174 if (m_strict_fifo) {
175 if (arrival_time < m_last_arrival_time) {
176 panic("FIFO ordering violated: %s name: %s current time: %d "
177 "delta: %d arrival_time: %d last arrival_time: %d\n",
178 *this, name(), current_time, delta, arrival_time,
179 m_last_arrival_time);
180 }
181 }
182
183 // If running a cache trace, don't worry about the last arrival checks
184 if (!RubySystem::getWarmupEnabled()) {
185 m_last_arrival_time = arrival_time;
186 }
187
188 // compute the delay cycles and set enqueue time
189 Message* msg_ptr = message.get();
190 assert(msg_ptr != NULL);
191
192 assert(current_time >= msg_ptr->getLastEnqueueTime() &&
193 "ensure we aren't dequeued early");
194
195 msg_ptr->updateDelayedTicks(current_time);
196 msg_ptr->setLastEnqueueTime(arrival_time);
197 msg_ptr->setMsgCounter(m_msg_counter);
198
199 // Insert the message into the priority heap
200 m_prio_heap.push_back(message);
201 push_heap(m_prio_heap.begin(), m_prio_heap.end(), greater<MsgPtr>());
202 // Increment the number of messages statistic
203 m_buf_msgs++;
204
205 DPRINTF(RubyQueue, "Enqueue arrival_time: %lld, Message: %s\n",
206 arrival_time, *(message.get()));
207
208 // Schedule the wakeup
209 assert(m_consumer != NULL);
210 m_consumer->scheduleEventAbsolute(arrival_time);
211 m_consumer->storeEventInfo(m_vnet_id);
212}
213
214Tick
215MessageBuffer::dequeue(Tick current_time, bool decrement_messages)
216{
217 DPRINTF(RubyQueue, "Popping\n");
218 assert(isReady(current_time));
219
220 // get MsgPtr of the message about to be dequeued
221 MsgPtr message = m_prio_heap.front();
222
223 // get the delay cycles
224 message->updateDelayedTicks(current_time);
225 Tick delay = message->getDelayedTicks();
226
227 m_stall_time = curTick() - message->getTime();
228
229 // record previous size and time so the current buffer size isn't
230 // adjusted until schd cycle
231 if (m_time_last_time_pop < current_time) {
232 m_size_at_cycle_start = m_prio_heap.size();
233 m_time_last_time_pop = current_time;
234 }
235
236 pop_heap(m_prio_heap.begin(), m_prio_heap.end(), greater<MsgPtr>());
237 m_prio_heap.pop_back();
238 if (decrement_messages) {
239 // If the message will be removed from the queue, decrement the
240 // number of message in the queue.
241 m_buf_msgs--;
242 }
243
244 return delay;
245}
246
247void
248MessageBuffer::clear()
249{
250 m_prio_heap.clear();
251
252 m_msg_counter = 0;
253 m_time_last_time_enqueue = 0;
254 m_time_last_time_pop = 0;
255 m_size_at_cycle_start = 0;
256 m_msgs_this_cycle = 0;
257}
258
259void
260MessageBuffer::recycle(Tick current_time, Tick recycle_latency)
261{
262 DPRINTF(RubyQueue, "Recycling.\n");
263 assert(isReady(current_time));
264 MsgPtr node = m_prio_heap.front();
265 pop_heap(m_prio_heap.begin(), m_prio_heap.end(), greater<MsgPtr>());
266
267 Tick future_time = current_time + recycle_latency;
268 node->setLastEnqueueTime(future_time);
269
270 m_prio_heap.back() = node;
271 push_heap(m_prio_heap.begin(), m_prio_heap.end(), greater<MsgPtr>());
272 m_consumer->scheduleEventAbsolute(future_time);
273}
274
275void
276MessageBuffer::reanalyzeList(list<MsgPtr> &lt, Tick schdTick)
277{
278 while (!lt.empty()) {
279 m_msg_counter++;
280 MsgPtr m = lt.front();
281 m->setLastEnqueueTime(schdTick);
282 m->setMsgCounter(m_msg_counter);
283
284 m_prio_heap.push_back(m);
285 push_heap(m_prio_heap.begin(), m_prio_heap.end(),
286 greater<MsgPtr>());
287
288 m_consumer->scheduleEventAbsolute(schdTick);
289 lt.pop_front();
290 }
291}
292
293void
294MessageBuffer::reanalyzeMessages(Addr addr, Tick current_time)
295{
296 DPRINTF(RubyQueue, "ReanalyzeMessages %#x\n", addr);
297 assert(m_stall_msg_map.count(addr) > 0);
298
299 //
300 // Put all stalled messages associated with this address back on the
301 // prio heap. The reanalyzeList call will make sure the consumer is
302 // scheduled for the current cycle so that the previously stalled messages
303 // will be observed before any younger messages that may arrive this cycle
304 //
305 m_stall_map_size -= m_stall_msg_map[addr].size();
306 assert(m_stall_map_size >= 0);
307 reanalyzeList(m_stall_msg_map[addr], current_time);
308 m_stall_msg_map.erase(addr);
309}
310
311void
312MessageBuffer::reanalyzeAllMessages(Tick current_time)
313{
314 DPRINTF(RubyQueue, "ReanalyzeAllMessages\n");
315
316 //
317 // Put all stalled messages associated with this address back on the
318 // prio heap. The reanalyzeList call will make sure the consumer is
319 // scheduled for the current cycle so that the previously stalled messages
320 // will be observed before any younger messages that may arrive this cycle.
321 //
322 for (StallMsgMapType::iterator map_iter = m_stall_msg_map.begin();
323 map_iter != m_stall_msg_map.end(); ++map_iter) {
324 m_stall_map_size -= map_iter->second.size();
325 assert(m_stall_map_size >= 0);
326 reanalyzeList(map_iter->second, current_time);
327 }
328 m_stall_msg_map.clear();
329}
330
331void
332MessageBuffer::stallMessage(Addr addr, Tick current_time)
333{
334 DPRINTF(RubyQueue, "Stalling due to %#x\n", addr);
335 assert(isReady(current_time));
336 assert(getOffset(addr) == 0);
337 MsgPtr message = m_prio_heap.front();
338
339 // Since the message will just be moved to stall map, indicate that the
340 // buffer should not decrement the m_buf_msgs statistic
341 dequeue(current_time, false);
342
343 //
344 // Note: no event is scheduled to analyze the map at a later time.
345 // Instead the controller is responsible to call reanalyzeMessages when
346 // these addresses change state.
347 //
348 (m_stall_msg_map[addr]).push_back(message);
349 m_stall_map_size++;
350 m_stall_count++;
351}
352
353void
354MessageBuffer::print(ostream& out) const
355{
356 ccprintf(out, "[MessageBuffer: ");
357 if (m_consumer != NULL) {
358 ccprintf(out, " consumer-yes ");
359 }
360
361 vector<MsgPtr> copy(m_prio_heap);
362 sort_heap(copy.begin(), copy.end(), greater<MsgPtr>());
363 ccprintf(out, "%s] %s", copy, name());
364}
365
366bool
367MessageBuffer::isReady(Tick current_time) const
368{
369 return ((m_prio_heap.size() > 0) &&
370 (m_prio_heap.front()->getLastEnqueueTime() <= current_time));
371}
372
373void
374MessageBuffer::regStats()
375{
376 m_not_avail_count
377 .name(name() + ".not_avail_count")
378 .desc("Number of times this buffer did not have N slots available")
379 .flags(Stats::nozero);
380
381 m_buf_msgs
382 .name(name() + ".avg_buf_msgs")
383 .desc("Average number of messages in buffer")
384 .flags(Stats::nozero);
385
386 m_stall_count
387 .name(name() + ".num_msg_stalls")
388 .desc("Number of times messages were stalled")
389 .flags(Stats::nozero);
390
391 m_occupancy
392 .name(name() + ".avg_buf_occ")
393 .desc("Average occupancy of buffer capacity")
394 .flags(Stats::nozero);
395
396 m_stall_time
397 .name(name() + ".avg_stall_time")
398 .desc("Average number of cycles messages are stalled in this MB")
399 .flags(Stats::nozero);
400
401 if (m_max_size > 0) {
402 m_occupancy = m_buf_msgs / m_max_size;
403 } else {
404 m_occupancy = 0;
405 }
406}
407
408uint32_t
409MessageBuffer::functionalWrite(Packet *pkt)
410{
411 uint32_t num_functional_writes = 0;
412
413 // Check the priority heap and write any messages that may
414 // correspond to the address in the packet.
415 for (unsigned int i = 0; i < m_prio_heap.size(); ++i) {
416 Message *msg = m_prio_heap[i].get();
417 if (msg->functionalWrite(pkt)) {
418 num_functional_writes++;
419 }
420 }
421
422 // Check the stall queue and write any messages that may
423 // correspond to the address in the packet.
424 for (StallMsgMapType::iterator map_iter = m_stall_msg_map.begin();
425 map_iter != m_stall_msg_map.end();
426 ++map_iter) {
427
428 for (std::list<MsgPtr>::iterator it = (map_iter->second).begin();
429 it != (map_iter->second).end(); ++it) {
430
431 Message *msg = (*it).get();
432 if (msg->functionalWrite(pkt)) {
433 num_functional_writes++;
434 }
435 }
436 }
437
438 return num_functional_writes;
439}
440
441MessageBuffer *
442MessageBufferParams::create()
443{
444 return new MessageBuffer(this);
445}