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/*
* Copyright (c) 1999-2008 Mark D. Hill and David A. Wood
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "mem/ruby/network/simple/PerfectSwitch.hh"
#include <algorithm>
#include "base/cast.hh"
#include "base/cprintf.hh"
#include "base/random.hh"
#include "debug/RubyNetwork.hh"
#include "mem/ruby/network/MessageBuffer.hh"
#include "mem/ruby/network/simple/SimpleNetwork.hh"
#include "mem/ruby/network/simple/Switch.hh"
#include "mem/ruby/slicc_interface/Message.hh"
const int PRIORITY_SWITCH_LIMIT = 128;
// Operator for helper class
bool
operator<(const LinkOrder& l1, const LinkOrder& l2)
{
return (l1.m_value < l2.m_value);
}
PerfectSwitch::PerfectSwitch(SwitchID sid, Switch *sw, uint32_t virt_nets)
: Consumer(sw), m_switch_id(sid), m_switch(sw)
{
m_round_robin_start = 0;
m_wakeups_wo_switch = 0;
m_virtual_networks = virt_nets;
}
void
PerfectSwitch::init(SimpleNetwork *network_ptr)
{
m_network_ptr = network_ptr;
for (int i = 0;i < m_virtual_networks;++i) {
m_pending_message_count.push_back(0);
}
}
void
PerfectSwitch::addInPort(const std::vector<MessageBuffer*>& in)
{
NodeID port = m_in.size();
m_in.push_back(in);
for (int i = 0; i < in.size(); ++i) {
if (in[i] != nullptr) {
in[i]->setConsumer(this);
in[i]->setIncomingLink(port);
in[i]->setVnet(i);
}
}
}
void
PerfectSwitch::addOutPort(const std::vector<MessageBuffer*>& out,
const NetDest& routing_table_entry)
{
// Setup link order
LinkOrder l;
l.m_value = 0;
l.m_link = m_out.size();
m_link_order.push_back(l);
// Add to routing table
m_out.push_back(out);
m_routing_table.push_back(routing_table_entry);
}
PerfectSwitch::~PerfectSwitch()
{
}
void
PerfectSwitch::operateVnet(int vnet)
{
// This is for round-robin scheduling
int incoming = m_round_robin_start;
m_round_robin_start++;
if (m_round_robin_start >= m_in.size()) {
m_round_robin_start = 0;
}
if (m_pending_message_count[vnet] > 0) {
// for all input ports, use round robin scheduling
for (int counter = 0; counter < m_in.size(); counter++) {
// Round robin scheduling
incoming++;
if (incoming >= m_in.size()) {
incoming = 0;
}
// Is there a message waiting?
if (m_in[incoming].size() <= vnet) {
continue;
}
MessageBuffer *buffer = m_in[incoming][vnet];
if (buffer == nullptr) {
continue;
}
operateMessageBuffer(buffer, incoming, vnet);
}
}
}
void
PerfectSwitch::operateMessageBuffer(MessageBuffer *buffer, int incoming,
int vnet)
{
MsgPtr msg_ptr;
Message *net_msg_ptr = NULL;
// temporary vectors to store the routing results
std::vector<LinkID> output_links;
std::vector<NetDest> output_link_destinations;
Tick current_time = m_switch->clockEdge();
while (buffer->isReady(current_time)) {
DPRINTF(RubyNetwork, "incoming: %d\n", incoming);
// Peek at message
msg_ptr = buffer->peekMsgPtr();
net_msg_ptr = msg_ptr.get();
DPRINTF(RubyNetwork, "Message: %s\n", (*net_msg_ptr));
output_links.clear();
output_link_destinations.clear();
NetDest msg_dsts = net_msg_ptr->getDestination();
// Unfortunately, the token-protocol sends some
// zero-destination messages, so this assert isn't valid
// assert(msg_dsts.count() > 0);
assert(m_link_order.size() == m_routing_table.size());
assert(m_link_order.size() == m_out.size());
if (m_network_ptr->getAdaptiveRouting()) {
if (m_network_ptr->isVNetOrdered(vnet)) {
// Don't adaptively route
for (int out = 0; out < m_out.size(); out++) {
m_link_order[out].m_link = out;
m_link_order[out].m_value = 0;
}
} else {
// Find how clogged each link is
for (int out = 0; out < m_out.size(); out++) {
int out_queue_length = 0;
for (int v = 0; v < m_virtual_networks; v++) {
out_queue_length += m_out[out][v]->getSize(current_time);
}
int value =
(out_queue_length << 8) |
random_mt.random(0, 0xff);
m_link_order[out].m_link = out;
m_link_order[out].m_value = value;
}
// Look at the most empty link first
sort(m_link_order.begin(), m_link_order.end());
}
}
for (int i = 0; i < m_routing_table.size(); i++) {
// pick the next link to look at
int link = m_link_order[i].m_link;
NetDest dst = m_routing_table[link];
DPRINTF(RubyNetwork, "dst: %s\n", dst);
if (!msg_dsts.intersectionIsNotEmpty(dst))
continue;
// Remember what link we're using
output_links.push_back(link);
// Need to remember which destinations need this message in
// another vector. This Set is the intersection of the
// routing_table entry and the current destination set. The
// intersection must not be empty, since we are inside "if"
output_link_destinations.push_back(msg_dsts.AND(dst));
// Next, we update the msg_destination not to include
// those nodes that were already handled by this link
msg_dsts.removeNetDest(dst);
}
assert(msg_dsts.count() == 0);
// Check for resources - for all outgoing queues
bool enough = true;
for (int i = 0; i < output_links.size(); i++) {
int outgoing = output_links[i];
if (!m_out[outgoing][vnet]->areNSlotsAvailable(1, current_time))
enough = false;
DPRINTF(RubyNetwork, "Checking if node is blocked ..."
"outgoing: %d, vnet: %d, enough: %d\n",
outgoing, vnet, enough);
}
// There were not enough resources
if (!enough) {
scheduleEvent(Cycles(1));
DPRINTF(RubyNetwork, "Can't deliver message since a node "
"is blocked\n");
DPRINTF(RubyNetwork, "Message: %s\n", (*net_msg_ptr));
break; // go to next incoming port
}
MsgPtr unmodified_msg_ptr;
if (output_links.size() > 1) {
// If we are sending this message down more than one link
// (size>1), we need to make a copy of the message so each
// branch can have a different internal destination we need
// to create an unmodified MsgPtr because the MessageBuffer
// enqueue func will modify the message
// This magic line creates a private copy of the message
unmodified_msg_ptr = msg_ptr->clone();
}
// Dequeue msg
buffer->dequeue(current_time);
m_pending_message_count[vnet]--;
// Enqueue it - for all outgoing queues
for (int i=0; i<output_links.size(); i++) {
int outgoing = output_links[i];
if (i > 0) {
// create a private copy of the unmodified message
msg_ptr = unmodified_msg_ptr->clone();
}
// Change the internal destination set of the message so it
// knows which destinations this link is responsible for.
net_msg_ptr = msg_ptr.get();
net_msg_ptr->getDestination() = output_link_destinations[i];
// Enqeue msg
DPRINTF(RubyNetwork, "Enqueuing net msg from "
"inport[%d][%d] to outport [%d][%d].\n",
incoming, vnet, outgoing, vnet);
m_out[outgoing][vnet]->enqueue(msg_ptr, current_time,
m_switch->cyclesToTicks(Cycles(1)));
}
}
}
void
PerfectSwitch::wakeup()
{
// Give the highest numbered link priority most of the time
m_wakeups_wo_switch++;
int highest_prio_vnet = m_virtual_networks-1;
int lowest_prio_vnet = 0;
int decrementer = 1;
// invert priorities to avoid starvation seen in the component network
if (m_wakeups_wo_switch > PRIORITY_SWITCH_LIMIT) {
m_wakeups_wo_switch = 0;
highest_prio_vnet = 0;
lowest_prio_vnet = m_virtual_networks-1;
decrementer = -1;
}
// For all components incoming queues
for (int vnet = highest_prio_vnet;
(vnet * decrementer) >= (decrementer * lowest_prio_vnet);
vnet -= decrementer) {
operateVnet(vnet);
}
}
void
PerfectSwitch::storeEventInfo(int info)
{
m_pending_message_count[info]++;
}
void
PerfectSwitch::clearStats()
{
}
void
PerfectSwitch::collateStats()
{
}
void
PerfectSwitch::print(std::ostream& out) const
{
out << "[PerfectSwitch " << m_switch_id << "]";
}