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authorKorey Sewell <ksewell@umich.edu>2010-01-31 18:27:38 -0500
committerKorey Sewell <ksewell@umich.edu>2010-01-31 18:27:38 -0500
commit90d3b45a566847fe15095b92238e32973ad9cc0e (patch)
tree9deb58c0889ec67a5aefdf66cf90c1cd9c311b04
parent3eb04b4ad73cb66e86d09ffd5989a93d9f62b299 (diff)
downloadgem5-90d3b45a566847fe15095b92238e32973ad9cc0e.tar.xz
inorder: ready thread wakeup
allow a thread to wakeup and be activated after it has been in suspended state and another thread is switched out. Need to give pipeline stages a "activateThread" function so that can get to their suspended instruction when the time is right.
-rw-r--r--src/cpu/inorder/cpu.cc14
-rw-r--r--src/cpu/inorder/cpu.hh3
-rw-r--r--src/cpu/inorder/pipeline_stage.cc30
-rw-r--r--src/cpu/inorder/pipeline_stage.hh2
-rw-r--r--src/cpu/inorder/resources/cache_unit.cc5
5 files changed, 51 insertions, 3 deletions
diff --git a/src/cpu/inorder/cpu.cc b/src/cpu/inorder/cpu.cc
index ec6bb21ee..501150386 100644
--- a/src/cpu/inorder/cpu.cc
+++ b/src/cpu/inorder/cpu.cc
@@ -674,6 +674,8 @@ InOrderCPU::activateNextReadyThread()
DPRINTF(InOrderCPU,
"Attempting to activate new thread, but No Ready Threads to"
"activate.\n");
+ DPRINTF(InOrderCPU,
+ "Unable to switch to next active thread.\n");
}
}
@@ -696,7 +698,7 @@ InOrderCPU::activateThread(ThreadID tid)
"Ignoring activation of [tid:%i], since [tid:%i] is "
"already running.\n", tid, activeThreadId());
- DPRINTF(InOrderCPU,"Placing [tid:%i] ready threads list\n",
+ DPRINTF(InOrderCPU,"Placing [tid:%i] on ready threads list\n",
tid);
readyThreads.push_back(tid);
@@ -706,11 +708,21 @@ InOrderCPU::activateThread(ThreadID tid)
"Adding [tid:%i] to active threads list.\n", tid);
activeThreads.push_back(tid);
+ activateThreadInPipeline(tid);
+
wakeCPU();
}
}
void
+InOrderCPU::activateThreadInPipeline(ThreadID tid)
+{
+ for (int stNum=0; stNum < NumStages; stNum++) {
+ pipelineStage[stNum]->activateThread(tid);
+ }
+}
+
+void
InOrderCPU::deactivateContext(ThreadID tid, int delay)
{
DPRINTF(InOrderCPU,"[tid:%i]: Deactivating ...\n", tid);
diff --git a/src/cpu/inorder/cpu.hh b/src/cpu/inorder/cpu.hh
index 7ac433723..1e514e1ed 100644
--- a/src/cpu/inorder/cpu.hh
+++ b/src/cpu/inorder/cpu.hh
@@ -346,7 +346,8 @@ class InOrderCPU : public BaseCPU
/** Add Thread to Active Threads List. */
void activateContext(ThreadID tid, int delay = 0);
void activateThread(ThreadID tid);
-
+ void activateThreadInPipeline(ThreadID tid);
+
/** Add Thread to Active Threads List. */
void activateNextReadyContext(int delay = 0);
void activateNextReadyThread();
diff --git a/src/cpu/inorder/pipeline_stage.cc b/src/cpu/inorder/pipeline_stage.cc
index 30a3733b0..ef91f206b 100644
--- a/src/cpu/inorder/pipeline_stage.cc
+++ b/src/cpu/inorder/pipeline_stage.cc
@@ -558,6 +558,28 @@ PipelineStage::updateStatus()
}
}
+void
+PipelineStage::activateThread(ThreadID tid)
+{
+ if (cpu->threadModel == InOrderCPU::SwitchOnCacheMiss) {
+ if (!switchedOutValid[tid]) {
+ DPRINTF(InOrderStage, "[tid:%i] No instruction available in "
+ "switch out buffer.\n", tid);
+ } else {
+ DynInstPtr inst = switchedOutBuffer[tid];
+
+ DPRINTF(InOrderStage,"[tid:%i]: Re-Inserting [sn:%lli] PC:%#x into stage skidBuffer %i\n",
+ tid, inst->seqNum, inst->readPC(), inst->threadNumber);
+
+ skidBuffer[tid].push(inst);
+
+ switchedOutBuffer[tid] = NULL;
+
+ switchedOutValid[tid] = false;
+ }
+ }
+
+}
void
@@ -945,6 +967,11 @@ PipelineStage::processInstSchedule(DynInstPtr inst)
if (req->isMemStall() &&
cpu->threadModel == InOrderCPU::SwitchOnCacheMiss) {
// Save Stalling Instruction
+ DPRINTF(ThreadModel, "[tid:%i] Detected cache miss.\n", tid);
+
+ DPRINTF(InOrderStage, "Inserting [tid:%i][sn:%i] into switch out buffer.\n",
+ tid, inst->seqNum);
+
switchedOutBuffer[tid] = inst;
switchedOutValid[tid] = true;
@@ -956,9 +983,12 @@ PipelineStage::processInstSchedule(DynInstPtr inst)
// Switch On Cache Miss
//=====================
// Suspend Thread at end of cycle
+ DPRINTF(ThreadModel, "Suspending [tid:%i] due to cache miss.\n", tid);
cpu->suspendContext(tid);
// Activate Next Ready Thread at end of cycle
+ DPRINTF(ThreadModel, "Attempting to activate next ready thread due to"
+ " cache miss.\n");
cpu->activateNextReadyContext();
}
diff --git a/src/cpu/inorder/pipeline_stage.hh b/src/cpu/inorder/pipeline_stage.hh
index f10906e4c..dfe1ac7c3 100644
--- a/src/cpu/inorder/pipeline_stage.hh
+++ b/src/cpu/inorder/pipeline_stage.hh
@@ -235,6 +235,8 @@ class PipelineStage
public:
+ virtual void activateThread(ThreadID tid);
+
/** Squashes if there is a PC-relative branch that was predicted
* incorrectly. Sends squash information back to fetch.
*/
diff --git a/src/cpu/inorder/resources/cache_unit.cc b/src/cpu/inorder/resources/cache_unit.cc
index 3de5c518a..2cf6c3195 100644
--- a/src/cpu/inorder/resources/cache_unit.cc
+++ b/src/cpu/inorder/resources/cache_unit.cc
@@ -708,9 +708,12 @@ CacheUnit::processCacheCompletion(PacketPtr pkt)
if (cache_req->isMemStall() &&
cpu->threadModel == InOrderCPU::SwitchOnCacheMiss) {
- DPRINTF(InOrderCachePort, "[tid:%u] Waking up from Cache Miss.\n");
+ DPRINTF(InOrderCachePort, "[tid:%u] Waking up from Cache Miss.\n", tid);
cpu->activateContext(tid);
+
+ DPRINTF(ThreadModel, "Activating [tid:%i] after return from cache"
+ "miss.\n", tid);
}
// Wake up the CPU (if it went to sleep and was waiting on this