changeset e5550966464a in /z/repo/m5
details: http://repo.m5sim.org/m5?cmd=changeset;node=e5550966464a
description:
Ruby: Improve Change PerfectSwitch's wakeup function
Currently the wakeup function for the PerfectSwitch contains three
loops -
loop on number of virtual networks
loop on number of incoming links
loop till all messages for this (link, network) have been
routed
With an 8 processor mesh network and Hammer protocol, about 11-12% of
the
was observed to have been spent in this function, which is the highest
amongst all the functions. It was found that the innermost loop is
executed
about 45 times per invocation of the wakeup function, when each
invocation
of the wakeup function processes just about one message.
The patch tries to do away with the redundant executions of the
innermost
loop. Counters have been added for each virtual network that record the
number of messages that need to be routed for that virtual network. The
inner loops are only executed when the number of messages for that
particular
virtual network > 0. This does away with almost 80% of the executions
of the
innermost loop. The function now consumes about 5-6% of the total
execution
time.
diffstat:
src/mem/ruby/buffers/MessageBuffer.cc | 3 +
src/mem/ruby/buffers/MessageBuffer.hh | 6 +
src/mem/ruby/common/Consumer.hh | 1 +
src/mem/ruby/network/simple/PerfectSwitch.cc | 285 +++++++++++++-----------
src/mem/ruby/network/simple/PerfectSwitch.hh | 2 +
src/mem/ruby/slicc_interface/Message.hh | 2 +
src/mem/ruby/slicc_interface/NetworkMessage.hh | 7 +
7 files changed, 172 insertions(+), 134 deletions(-)
diffs (truncated from 441 to 300 lines):
diff -r 42f772dc5a96 -r e5550966464a src/mem/ruby/buffers/MessageBuffer.cc
--- a/src/mem/ruby/buffers/MessageBuffer.cc Sun Feb 13 17:46:04 2011 -0800
+++ b/src/mem/ruby/buffers/MessageBuffer.cc Mon Feb 14 16:14:54 2011 -0600
@@ -58,6 +58,8 @@
m_name = name;
m_stall_msg_map.clear();
+ m_input_link_id = 0;
+ m_vnet_id = 0;
}
int
@@ -228,6 +230,7 @@
// Schedule the wakeup
if (m_consumer_ptr != NULL) {
g_eventQueue_ptr->scheduleEventAbsolute(m_consumer_ptr, arrival_time);
+ m_consumer_ptr->storeEventInfo(m_vnet_id);
} else {
panic("No consumer: %s name: %s\n", *this, m_name);
}
diff -r 42f772dc5a96 -r e5550966464a src/mem/ruby/buffers/MessageBuffer.hh
--- a/src/mem/ruby/buffers/MessageBuffer.hh Sun Feb 13 17:46:04 2011 -0800
+++ b/src/mem/ruby/buffers/MessageBuffer.hh Mon Feb 14 16:14:54 2011 -0600
@@ -142,6 +142,9 @@
void printStats(std::ostream& out);
void clearStats() { m_not_avail_count = 0; m_msg_counter = 0; }
+ void setIncomingLink(int link_id) { m_input_link_id = link_id; }
+ void setVnet(int net) { m_vnet_id = net; }
+
private:
//added by SS
int m_recycle_latency;
@@ -184,6 +187,9 @@
bool m_ordering_set;
bool m_randomization;
Time m_last_arrival_time;
+
+ int m_input_link_id;
+ int m_vnet_id;
};
inline std::ostream&
diff -r 42f772dc5a96 -r e5550966464a src/mem/ruby/common/Consumer.hh
--- a/src/mem/ruby/common/Consumer.hh Sun Feb 13 17:46:04 2011 -0800
+++ b/src/mem/ruby/common/Consumer.hh Mon Feb 14 16:14:54 2011 -0600
@@ -67,6 +67,7 @@
virtual void wakeup() = 0;
virtual void print(std::ostream& out) const = 0;
+ virtual void storeEventInfo(int info) {}
const Time&
getLastScheduledWakeup() const
diff -r 42f772dc5a96 -r e5550966464a
src/mem/ruby/network/simple/PerfectSwitch.cc
--- a/src/mem/ruby/network/simple/PerfectSwitch.cc Sun Feb 13 17:46:04
2011 -0800
+++ b/src/mem/ruby/network/simple/PerfectSwitch.cc Mon Feb 14 16:14:54
2011 -0600
@@ -54,6 +54,11 @@
m_round_robin_start = 0;
m_network_ptr = network_ptr;
m_wakeups_wo_switch = 0;
+
+ for(int i = 0;i < m_virtual_networks;++i)
+ {
+ m_pending_message_count.push_back(0);
+ }
}
void
@@ -62,12 +67,15 @@
assert(in.size() == m_virtual_networks);
NodeID port = m_in.size();
m_in.push_back(in);
+
for (int j = 0; j < m_virtual_networks; j++) {
m_in[port][j]->setConsumer(this);
string desc = csprintf("[Queue from port %s %s %s to PerfectSwitch]",
NodeIDToString(m_switch_id), NodeIDToString(port),
NodeIDToString(j));
m_in[port][j]->setDescription(desc);
+ m_in[port][j]->setIncomingLink(port);
+ m_in[port][j]->setVnet(j);
}
}
@@ -154,161 +162,170 @@
m_round_robin_start = 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;
- }
+ 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;
+ }
- // temporary vectors to store the routing results
- vector<LinkID> output_links;
- vector<NetDest> output_link_destinations;
+ // temporary vectors to store the routing results
+ vector<LinkID> output_links;
+ vector<NetDest> output_link_destinations;
- // Is there a message waiting?
- while (m_in[incoming][vnet]->isReady()) {
- DPRINTF(RubyNetwork, "incoming: %d\n", incoming);
+ // Is there a message waiting?
+ while (m_in[incoming][vnet]->isReady()) {
+ DPRINTF(RubyNetwork, "incoming: %d\n", incoming);
- // Peek at message
- msg_ptr = m_in[incoming][vnet]->peekMsgPtr();
- net_msg_ptr = safe_cast<NetworkMessage*>(msg_ptr.get());
- DPRINTF(RubyNetwork, "Message: %s\n", (*net_msg_ptr));
+ // Peek at message
+ msg_ptr = m_in[incoming][vnet]->peekMsgPtr();
+ net_msg_ptr = safe_cast<NetworkMessage*>(msg_ptr.get());
+ DPRINTF(RubyNetwork, "Message: %s\n", (*net_msg_ptr));
- output_links.clear();
- output_link_destinations.clear();
- NetDest msg_dsts =
- net_msg_ptr->getInternalDestination();
+ output_links.clear();
+ output_link_destinations.clear();
+ NetDest msg_dsts =
+ net_msg_ptr->getInternalDestination();
- // Unfortunately, the token-protocol sends some
- // zero-destination messages, so this assert isn't valid
- // assert(msg_dsts.count() > 0);
+ // 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());
+ 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;
+ 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();
+ }
+ int value =
+ (out_queue_length << 8) | (random() &
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());
}
- } 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();
- }
- int value =
- (out_queue_length << 8) | (random() & 0xff);
- m_link_order[out].m_link = out;
- m_link_order[out].m_value = value;
+ }
+
+ 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);
+ //assert(output_links.size() > 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))
+ enough = false;
+ DPRINTF(RubyNetwork, "Checking if node is blocked\n"
+ "outgoing: %d, vnet: %d, enough: %d\n",
+ outgoing, vnet, enough);
+ }
+
+ // There were not enough resources
+ if (!enough) {
+ g_eventQueue_ptr->scheduleEvent(this, 1);
+ DPRINTF(RubyNetwork, "Can't deliver message since a
node "
+ "is blocked\n"
+ "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();
+ }
+
+ // 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();
}
- // Look at the most empty link first
- sort(m_link_order.begin(), m_link_order.end());
- }
- }
+ // Change the internal destination set of the
+ // message so it knows which destinations this
+ // link is responsible for.
+ net_msg_ptr =
safe_cast<NetworkMessage*>(msg_ptr.get());
+ net_msg_ptr->getInternalDestination() =
+ output_link_destinations[i];
- 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);
+ // Enqeue msg
+ DPRINTF(RubyNetwork, "Switch: %d enqueuing net msg
from "
+ "inport[%d][%d] to outport [%d][%d] time:
%lld.\n",
+ m_switch_id, incoming, vnet, outgoing, vnet,
+ g_eventQueue_ptr->getTime());
- 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
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