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mem-ruby: Fix message stall time calculation

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Three changes below:
1. The m_stall_time was declared as statistics::Average, but
statistics::Average uses AvgStor as storage and this works as per-tick
average stat. In the case of m_stall_time, Scalar should be used to get
the calculation right.

2. The function used to get an enqueue time was changed since the
getTime() returns the time when the message was created.

3. Record the stall time only when the message is really dequeued
from the buffer (stall time is not evaluated when the message is moved
to stall map).

Change-Id: I090d19828b5c43f0843a8b735d3f00f312c436e9
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/54363
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This commit is contained in:
Daecheol You
2021-12-17 10:16:19 +09:00
parent ee5b65955e
commit ec58d9d7f3
2 changed files with 32 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

38
src/mem/ruby/network/MessageBuffer.cc
View File

@@ -64,13 +64,23 @@ MessageBuffer::MessageBuffer(const Params &p)
m_last_arrival_time(0), m_strict_fifo(p.ordered),
m_randomization(p.randomization),
m_allow_zero_latency(p.allow_zero_latency),
ADD_STAT(m_not_avail_count, "Number of times this buffer did not have "
"N slots available"),
ADD_STAT(m_buf_msgs, "Average number of messages in buffer"),
ADD_STAT(m_stall_time, "Average number of cycles messages are stalled in "
"this MB"),
ADD_STAT(m_stall_count, "Number of times messages were stalled"),
ADD_STAT(m_occupancy, "Average occupancy of buffer capacity")
ADD_STAT(m_not_avail_count, statistics::units::Count::get(),
"Number of times this buffer did not have N slots available"),
ADD_STAT(m_msg_count, statistics::units::Count::get(),
"Number of messages passed the buffer"),
ADD_STAT(m_buf_msgs, statistics::units::Rate<
statistics::units::Count, statistics::units::Tick>::get(),
"Average number of messages in buffer"),
ADD_STAT(m_stall_time, statistics::units::Tick::get(),
"Total number of ticks messages were stalled in this buffer"),
ADD_STAT(m_stall_count, statistics::units::Count::get(),
"Number of times messages were stalled"),
ADD_STAT(m_avg_stall_time, statistics::units::Rate<
statistics::units::Tick, statistics::units::Count>::get(),
"Average stall ticks per message"),
ADD_STAT(m_occupancy, statistics::units::Rate<
statistics::units::Ratio, statistics::units::Tick>::get(),
"Average occupancy of buffer capacity")
{
m_msg_counter = 0;
m_consumer = NULL;
@@ -93,12 +103,18 @@ MessageBuffer::MessageBuffer(const Params &p)
m_not_avail_count
.flags(statistics::nozero);
m_msg_count
.flags(statistics::nozero);
m_buf_msgs
.flags(statistics::nozero);
m_stall_count
.flags(statistics::nozero);
m_avg_stall_time
.flags(statistics::nozero | statistics::nonan);
m_occupancy
.flags(statistics::nozero);
@@ -110,6 +126,8 @@ MessageBuffer::MessageBuffer(const Params &p)
} else {
m_occupancy = 0;
}
m_avg_stall_time = m_stall_time / m_msg_count;
}
unsigned int
@@ -288,8 +306,6 @@ MessageBuffer::dequeue(Tick current_time, bool decrement_messages)
message->updateDelayedTicks(current_time);
Tick delay = message->getDelayedTicks();
m_stall_time = curTick() - message->getTime();
// record previous size and time so the current buffer size isn't
// adjusted until schd cycle
if (m_time_last_time_pop < current_time) {
@@ -301,6 +317,10 @@ MessageBuffer::dequeue(Tick current_time, bool decrement_messages)
pop_heap(m_prio_heap.begin(), m_prio_heap.end(), std::greater<MsgPtr>());
m_prio_heap.pop_back();
if (decrement_messages) {
// Record how much time is passed since the message was enqueued
m_stall_time += curTick() - message->getLastEnqueueTime();
m_msg_count++;
// If the message will be removed from the queue, decrement the
// number of message in the queue.
m_buf_msgs--;

4
src/mem/ruby/network/MessageBuffer.hh
View File

@@ -264,9 +264,11 @@ class MessageBuffer : public SimObject
// Count the # of times I didn't have N slots available
statistics::Scalar m_not_avail_count;
statistics::Scalar m_msg_count;
statistics::Average m_buf_msgs;
statistics::Average m_stall_time;
statistics::Scalar m_stall_time;
statistics::Scalar m_stall_count;
statistics::Formula m_avg_stall_time;
statistics::Formula m_occupancy;
};