changeset 560d7fbbddd1 in /z/repo/gem5
details: http://repo.gem5.org/gem5?cmd=changeset;node=560d7fbbddd1
description:
cpu: Add SMT support to MinorCPU
This patch adds SMT support to the MinorCPU. Currently
RoundRobin or Random thread scheduling are supported.
Change-Id: I91faf39ff881af5918cca05051829fc6261f20e3
diffstat:
src/cpu/minor/MinorCPU.py | 4 +
src/cpu/minor/cpu.cc | 59 +--
src/cpu/minor/cpu.hh | 23 +
src/cpu/minor/decode.cc | 161 ++++++---
src/cpu/minor/decode.hh | 63 ++-
src/cpu/minor/dyn_inst.cc | 6 +
src/cpu/minor/exec_context.hh | 13 +-
src/cpu/minor/execute.cc | 672 +++++++++++++++++++++++++-----------------
src/cpu/minor/execute.hh | 118 ++++--
src/cpu/minor/fetch1.cc | 273 +++++++++++-----
src/cpu/minor/fetch1.hh | 73 +++-
src/cpu/minor/fetch2.cc | 251 +++++++++------
src/cpu/minor/fetch2.hh | 107 ++++--
src/cpu/minor/lsq.cc | 56 ++-
src/cpu/minor/lsq.hh | 8 +-
src/cpu/minor/pipe_data.cc | 9 +-
src/cpu/minor/pipe_data.hh | 15 +-
src/cpu/minor/pipeline.cc | 9 +-
src/cpu/minor/pipeline.hh | 2 +-
src/sim/pseudo_inst.cc | 2 +-
util/minorview/minor.pic | 12 +-
21 files changed, 1245 insertions(+), 691 deletions(-)
diffs (truncated from 3613 to 300 lines):
diff -r b11410957c9e -r 560d7fbbddd1 src/cpu/minor/MinorCPU.py
--- a/src/cpu/minor/MinorCPU.py Thu Jul 21 17:19:15 2016 +0100
+++ b/src/cpu/minor/MinorCPU.py Thu Jul 21 17:19:16 2016 +0100
@@ -169,6 +169,8 @@
MinorDefaultFloatSimdFU(), MinorDefaultMemFU(),
MinorDefaultMiscFU()]
+class ThreadPolicy(Enum): vals = ['SingleThreaded', 'RoundRobin', 'Random']
+
class MinorCPU(BaseCPU):
type = 'MinorCPU'
cxx_header = "cpu/minor/cpu.hh"
@@ -185,6 +187,8 @@
def support_take_over(cls):
return True
+ threadPolicy = Param.ThreadPolicy('RoundRobin',
+ "Thread scheduling policy")
fetch1FetchLimit = Param.Unsigned(1,
"Number of line fetches allowable in flight at once")
fetch1LineSnapWidth = Param.Unsigned(0,
diff -r b11410957c9e -r 560d7fbbddd1 src/cpu/minor/cpu.cc
--- a/src/cpu/minor/cpu.cc Thu Jul 21 17:19:15 2016 +0100
+++ b/src/cpu/minor/cpu.cc Thu Jul 21 17:19:16 2016 +0100
@@ -47,32 +47,33 @@
#include "debug/Quiesce.hh"
MinorCPU::MinorCPU(MinorCPUParams *params) :
- BaseCPU(params)
+ BaseCPU(params),
+ threadPolicy(params->threadPolicy)
{
/* This is only written for one thread at the moment */
Minor::MinorThread *thread;
- if (FullSystem) {
- thread = new Minor::MinorThread(this, 0, params->system, params->itb,
- params->dtb, params->isa[0]);
- } else {
- /* thread_id 0 */
- thread = new Minor::MinorThread(this, 0, params->system,
- params->workload[0], params->itb, params->dtb, params->isa[0]);
+ for (ThreadID i = 0; i < numThreads; i++) {
+ if (FullSystem) {
+ thread = new Minor::MinorThread(this, i, params->system,
+ params->itb, params->dtb, params->isa[i]);
+ thread->setStatus(ThreadContext::Halted);
+ } else {
+ thread = new Minor::MinorThread(this, i, params->system,
+ params->workload[i], params->itb, params->dtb,
+ params->isa[i]);
+ }
+
+ threads.push_back(thread);
+ ThreadContext *tc = thread->getTC();
+ threadContexts.push_back(tc);
}
- threads.push_back(thread);
-
- thread->setStatus(ThreadContext::Halted);
-
- ThreadContext *tc = thread->getTC();
if (params->checker) {
fatal("The Minor model doesn't support checking (yet)\n");
}
- threadContexts.push_back(tc);
-
Minor::MinorDynInst::init();
pipeline = new Minor::Pipeline(*this, *params);
@@ -137,9 +138,6 @@
void
MinorCPU::unserializeThread(CheckpointIn &cp, ThreadID thread_id)
{
- if (thread_id != 0)
- fatal("Trying to load more than one thread into a MinorCPU\n");
-
threads[thread_id]->unserialize(cp);
}
@@ -170,11 +168,11 @@
MinorCPU::wakeup(ThreadID tid)
{
DPRINTF(Drain, "[tid:%d] MinorCPU wakeup\n", tid);
+ assert(tid < numThreads);
- if (threads[tid]->status() == ThreadContext::Suspended)
+ if (threads[tid]->status() == ThreadContext::Suspended) {
threads[tid]->activate();
-
- DPRINTF(Drain,"Suspended Processor awoke\n");
+ }
}
void
@@ -187,13 +185,10 @@
for (auto i = threads.begin(); i != threads.end(); i ++)
(*i)->startup();
- /* Workaround cases in SE mode where a thread is activated with an
- * incorrect PC that is updated after the call to activate. This
- * causes problems for Minor since it instantiates a virtual
- * branch instruction when activateContext() is called which ends
- * up pointing to an illegal address. */
- if (threads[0]->status() == ThreadContext::Active)
- activateContext(0);
+ for (ThreadID tid = 0; tid < numThreads; tid++) {
+ threads[tid]->startup();
+ pipeline->wakeupFetch(tid);
+ }
}
DrainState
@@ -246,6 +241,7 @@
for (ThreadID tid = 0; tid < numThreads; tid++)
wakeup(tid);
+
pipeline->drainResume();
}
@@ -278,7 +274,7 @@
void
MinorCPU::activateContext(ThreadID thread_id)
{
- DPRINTF(MinorCPU, "ActivateContext thread: %d", thread_id);
+ DPRINTF(MinorCPU, "ActivateContext thread: %d\n", thread_id);
/* Do some cycle accounting. lastStopped is reset to stop the
* wakeup call on the pipeline from adding the quiesce period
@@ -289,7 +285,7 @@
/* Wake up the thread, wakeup the pipeline tick */
threads[thread_id]->activate();
wakeupOnEvent(Minor::Pipeline::CPUStageId);
- pipeline->wakeupFetch();
+ pipeline->wakeupFetch(thread_id);
BaseCPU::activateContext(thread_id);
}
@@ -317,9 +313,6 @@
MinorCPU *
MinorCPUParams::create()
{
- numThreads = 1;
- if (!FullSystem && workload.size() != 1)
- panic("only one workload allowed");
return new MinorCPU(this);
}
diff -r b11410957c9e -r 560d7fbbddd1 src/cpu/minor/cpu.hh
--- a/src/cpu/minor/cpu.hh Thu Jul 21 17:19:15 2016 +0100
+++ b/src/cpu/minor/cpu.hh Thu Jul 21 17:19:16 2016 +0100
@@ -50,6 +50,7 @@
#include "cpu/minor/stats.hh"
#include "cpu/base.hh"
#include "cpu/simple_thread.hh"
+#include "enums/ThreadPolicy.hh"
#include "params/MinorCPU.hh"
namespace Minor
@@ -109,6 +110,8 @@
};
+ /** Thread Scheduling Policy (RoundRobin, Random, etc) */
+ Enums::ThreadPolicy threadPolicy;
protected:
/** Return a reference to the data port. */
MasterPort &getDataPort() override;
@@ -162,6 +165,26 @@
void activateContext(ThreadID thread_id) override;
void suspendContext(ThreadID thread_id) override;
+ /** Thread scheduling utility functions */
+ std::vector<ThreadID> roundRobinPriority(ThreadID priority)
+ {
+ std::vector<ThreadID> prio_list;
+ for (ThreadID i = 1; i <= numThreads; i++) {
+ prio_list.push_back((priority + i) % numThreads);
+ }
+ return prio_list;
+ }
+
+ std::vector<ThreadID> randomPriority()
+ {
+ std::vector<ThreadID> prio_list;
+ for (ThreadID i = 0; i < numThreads; i++) {
+ prio_list.push_back(i);
+ }
+ std::random_shuffle(prio_list.begin(), prio_list.end());
+ return prio_list;
+ }
+
/** Interface for stages to signal that they have become active after
* a callback or eventq event where the pipeline itself may have
* already been idled. The stage argument should be from the
diff -r b11410957c9e -r 560d7fbbddd1 src/cpu/minor/decode.cc
--- a/src/cpu/minor/decode.cc Thu Jul 21 17:19:15 2016 +0100
+++ b/src/cpu/minor/decode.cc Thu Jul 21 17:19:16 2016 +0100
@@ -49,7 +49,7 @@
MinorCPUParams ¶ms,
Latch<ForwardInstData>::Output inp_,
Latch<ForwardInstData>::Input out_,
- Reservable &next_stage_input_buffer) :
+ std::vector<InputBuffer<ForwardInstData>> &next_stage_input_buffer) :
Named(name),
cpu(cpu_),
inp(inp_),
@@ -57,11 +57,8 @@
nextStageReserve(next_stage_input_buffer),
outputWidth(params.executeInputWidth),
processMoreThanOneInput(params.decodeCycleInput),
- inputBuffer(name + ".inputBuffer", "insts", params.decodeInputBufferSize),
- inputIndex(0),
- inMacroop(false),
- execSeqNum(InstId::firstExecSeqNum),
- blocked(false)
+ decodeInfo(params.numThreads),
+ threadPriority(0)
{
if (outputWidth < 1)
fatal("%s: executeInputWidth must be >= 1 (%d)\n", name, outputWidth);
@@ -70,29 +67,37 @@
fatal("%s: decodeInputBufferSize must be >= 1 (%d)\n", name,
params.decodeInputBufferSize);
}
+
+ /* Per-thread input buffers */
+ for (ThreadID tid = 0; tid < params.numThreads; tid++) {
+ inputBuffer.push_back(
+ InputBuffer<ForwardInstData>(
+ name + ".inputBuffer" + std::to_string(tid), "insts",
+ params.decodeInputBufferSize));
+ }
}
const ForwardInstData *
-Decode::getInput()
+Decode::getInput(ThreadID tid)
{
/* Get insts from the inputBuffer to work with */
- if (!inputBuffer.empty()) {
- const ForwardInstData &head = inputBuffer.front();
+ if (!inputBuffer[tid].empty()) {
+ const ForwardInstData &head = inputBuffer[tid].front();
- return (head.isBubble() ? NULL : &(inputBuffer.front()));
+ return (head.isBubble() ? NULL : &(inputBuffer[tid].front()));
} else {
return NULL;
}
}
void
-Decode::popInput()
+Decode::popInput(ThreadID tid)
{
- if (!inputBuffer.empty())
- inputBuffer.pop();
+ if (!inputBuffer[tid].empty())
+ inputBuffer[tid].pop();
- inputIndex = 0;
- inMacroop = false;
+ decodeInfo[tid].inputIndex = 0;
+ decodeInfo[tid].inMacroop = false;
}
#if TRACING_ON
@@ -117,32 +122,37 @@
void
Decode::evaluate()
{
- inputBuffer.setTail(*inp.outputWire);
+ /* Push input onto appropriate input buffer */
+ if (!inp.outputWire->isBubble())
+ inputBuffer[inp.outputWire->threadId].setTail(*inp.outputWire);
+
ForwardInstData &insts_out = *out.inputWire;
assert(insts_out.isBubble());
- blocked = false;
+ for (ThreadID tid = 0; tid < cpu.numThreads; tid++)
+ decodeInfo[tid].blocked = !nextStageReserve[tid].canReserve();
- if (!nextStageReserve.canReserve()) {
- blocked = true;
- } else {
- const ForwardInstData *insts_in = getInput();
+ ThreadID tid = getScheduledThread();
+
+ if (tid != InvalidThreadID) {
+ DecodeThreadInfo &decode_info = decodeInfo[tid];
+ const ForwardInstData *insts_in = getInput(tid);
unsigned int output_index = 0;
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