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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/Throttle.hh"
#include <cassert>
#include "base/cast.hh"
#include "base/cprintf.hh"
#include "debug/RubyNetwork.hh"
#include "mem/ruby/network/MessageBuffer.hh"
#include "mem/ruby/network/Network.hh"
#include "mem/ruby/network/simple/Switch.hh"
#include "mem/ruby/slicc_interface/Message.hh"
#include "mem/ruby/system/RubySystem.hh"
namespace gem5
{
namespace ruby
{
const int MESSAGE_SIZE_MULTIPLIER = 1000;
//const int BROADCAST_SCALING = 4; // Have a 16p system act like a 64p systems
const int BROADCAST_SCALING = 1;
const int PRIORITY_SWITCH_LIMIT = 128;
static int network_message_to_size(Message* net_msg_ptr);
Throttle::Throttle(int sID, RubySystem *rs, NodeID node, Cycles link_latency,
int link_bandwidth_multiplier, int endpoint_bandwidth,
Switch *em)
: Consumer(em),
m_switch_id(sID), m_switch(em), m_node(node),
m_ruby_system(rs),
throttleStats(em, node)
{
m_vnets = 0;
assert(link_bandwidth_multiplier > 0);
m_link_bandwidth_multiplier = link_bandwidth_multiplier;
m_link_latency = link_latency;
m_endpoint_bandwidth = endpoint_bandwidth;
m_wakeups_wo_switch = 0;
m_link_utilization_proxy = 0;
}
void
Throttle::addLinks(const std::vector<MessageBuffer*>& in_vec,
const std::vector<MessageBuffer*>& out_vec)
{
assert(in_vec.size() == out_vec.size());
for (int vnet = 0; vnet < in_vec.size(); ++vnet) {
MessageBuffer *in_ptr = in_vec[vnet];
MessageBuffer *out_ptr = out_vec[vnet];
m_vnets++;
m_units_remaining.push_back(0);
m_in.push_back(in_ptr);
m_out.push_back(out_ptr);
// Set consumer and description
in_ptr->setConsumer(this);
std::string desc = "[Queue to Throttle " +
std::to_string(m_switch_id) + " " + std::to_string(m_node) + "]";
}
}
void
Throttle::operateVnet(int vnet, int &bw_remaining, bool &schedule_wakeup,
MessageBuffer *in, MessageBuffer *out)
{
if (out == nullptr || in == nullptr) {
return;
}
assert(m_units_remaining[vnet] >= 0);
Tick current_time = m_switch->clockEdge();
while (bw_remaining > 0 && (in->isReady(current_time) ||
m_units_remaining[vnet] > 0) &&
out->areNSlotsAvailable(1, current_time)) {
// See if we are done transferring the previous message on
// this virtual network
if (m_units_remaining[vnet] == 0 && in->isReady(current_time)) {
// Find the size of the message we are moving
MsgPtr msg_ptr = in->peekMsgPtr();
Message *net_msg_ptr = msg_ptr.get();
m_units_remaining[vnet] +=
network_message_to_size(net_msg_ptr);
DPRINTF(RubyNetwork, "throttle: %d my bw %d bw spent "
"enqueueing net msg %d time: %lld.\n",
m_node, getLinkBandwidth(), m_units_remaining[vnet],
m_ruby_system->curCycle());
// Move the message
in->dequeue(current_time);
out->enqueue(msg_ptr, current_time,
m_switch->cyclesToTicks(m_link_latency));
// Count the message
(*(throttleStats.
m_msg_counts[net_msg_ptr->getMessageSize()]))[vnet]++;
DPRINTF(RubyNetwork, "%s\n", *out);
}
// Calculate the amount of bandwidth we spent on this message
int diff = m_units_remaining[vnet] - bw_remaining;
m_units_remaining[vnet] = std::max(0, diff);
bw_remaining = std::max(0, -diff);
}
if (bw_remaining > 0 && (in->isReady(current_time) ||
m_units_remaining[vnet] > 0) &&
!out->areNSlotsAvailable(1, current_time)) {
DPRINTF(RubyNetwork, "vnet: %d", vnet);
// schedule me to wakeup again because I'm waiting for my
// output queue to become available
schedule_wakeup = true;
}
}
void
Throttle::wakeup()
{
// Limits the number of message sent to a limited number of bytes/cycle.
assert(getLinkBandwidth() > 0);
int bw_remaining = getLinkBandwidth();
m_wakeups_wo_switch++;
bool schedule_wakeup = false;
// variable for deciding the direction in which to iterate
bool iteration_direction = false;
// invert priorities to avoid starvation seen in the component network
if (m_wakeups_wo_switch > PRIORITY_SWITCH_LIMIT) {
m_wakeups_wo_switch = 0;
iteration_direction = true;
}
if (iteration_direction) {
for (int vnet = 0; vnet < m_vnets; ++vnet) {
operateVnet(vnet, bw_remaining, schedule_wakeup,
m_in[vnet], m_out[vnet]);
}
} else {
for (int vnet = m_vnets-1; vnet >= 0; --vnet) {
operateVnet(vnet, bw_remaining, schedule_wakeup,
m_in[vnet], m_out[vnet]);
}
}
// We should only wake up when we use the bandwidth
// This is only mostly true
// assert(bw_remaining != getLinkBandwidth());
// Record that we used some or all of the link bandwidth this cycle
double ratio = 1.0 - (double(bw_remaining) / double(getLinkBandwidth()));
// If ratio = 0, we used no bandwidth, if ratio = 1, we used all
m_link_utilization_proxy += ratio;
if (bw_remaining > 0 && !schedule_wakeup) {
// We have extra bandwidth and our output buffer was
// available, so we must not have anything else to do until
// another message arrives.
DPRINTF(RubyNetwork, "%s not scheduled again\n", *this);
} else {
DPRINTF(RubyNetwork, "%s scheduled again\n", *this);
// We are out of bandwidth for this cycle, so wakeup next
// cycle and continue
scheduleEvent(Cycles(1));
}
}
void
Throttle::regStats()
{
for (MessageSizeType type = MessageSizeType_FIRST;
type < MessageSizeType_NUM; ++type) {
throttleStats.m_msg_counts[(unsigned int)type] =
new statistics::Vector(&throttleStats,
csprintf("msg_count.%s", MessageSizeType_to_string(type)).c_str());
throttleStats.m_msg_counts[(unsigned int)type]
->init(Network::getNumberOfVirtualNetworks())
.flags(statistics::nozero)
;
throttleStats.m_msg_bytes[(unsigned int) type] =
new statistics::Formula(&throttleStats,
csprintf("msg_bytes.%s", MessageSizeType_to_string(type)).c_str());
throttleStats.m_msg_bytes[(unsigned int) type]
->flags(statistics::nozero)
;
*(throttleStats.m_msg_bytes[(unsigned int) type]) =
*(throttleStats.m_msg_counts[type]) * statistics::constant(
Network::MessageSizeType_to_int(type));
}
}
void
Throttle::clearStats()
{
m_link_utilization_proxy = 0;
}
void
Throttle::collateStats()
{
double time_delta = double(m_ruby_system->curCycle() -
m_ruby_system->getStartCycle());
throttleStats.m_link_utilization =
100.0 * m_link_utilization_proxy / time_delta;
}
void
Throttle::print(std::ostream& out) const
{
ccprintf(out, "[%i bw: %i]", m_node, getLinkBandwidth());
}
int
network_message_to_size(Message *net_msg_ptr)
{
assert(net_msg_ptr != NULL);
int size = Network::MessageSizeType_to_int(net_msg_ptr->getMessageSize());
size *= MESSAGE_SIZE_MULTIPLIER;
// Artificially increase the size of broadcast messages
if (BROADCAST_SCALING > 1 && net_msg_ptr->getDestination().isBroadcast())
size *= BROADCAST_SCALING;
return size;
}
Throttle::
ThrottleStats::ThrottleStats(statistics::Group *parent, const NodeID &nodeID)
: statistics::Group(parent, csprintf("throttle%02i", nodeID).c_str()),
m_link_utilization(this, "link_utilization")
{
}
} // namespace ruby
} // namespace gem5