bug fix to avoid early unmapping of the workgroups, and maintain the correct fetch/issue order per wavefront

Author: amirkavyan

src/arch/southern-islands/emulator/WorkGroup.h

@@ -132,6 +132,9 @@ class WorkGroup
 	/// simulator
 	bool finished_timing = false;
 
+	/// Number of instructions issued for this workgroup
+	long long inflight_instructions = 0;
+
 	/// Wavefront pool that the work group is associated with.
 	WavefrontPool *wavefront_pool = nullptr;
 

src/arch/southern-islands/timing/BranchUnit.cc

@@ -17,6 +17,7 @@
  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
+#include <arch/southern-islands/emulator/WorkGroup.h>
 #include <arch/southern-islands/emulator/Wavefront.h>
 
 #include "BranchUnit.h"
@@ -103,6 +104,10 @@ void BranchUnit::Complete()
 		// Access complete, remove the uop from the queue, and get the
 		// iterator for the next element
 		it = write_buffer.erase(it);
+		assert(uop->getWorkGroup()
+				->inflight_instructions > 0);
+		uop->getWorkGroup()->
+				inflight_instructions--;
 
 		// Statistics
 		num_instructions++;

src/arch/southern-islands/timing/ComputeUnit.cc

@@ -178,7 +178,7 @@ void ComputeUnit::Issue(FetchBuffer *fetch_buffer)
 				"cu=%d "
 				"wf=%d "
 				"uop_id=%lld "
-				"stg=\"i\"\n",
+				"stg=\"s\"\n",
 				uop->getIdInComputeUnit(),
 				index,
 				uop->getWavefront()->getId(),
@@ -252,24 +252,19 @@ void ComputeUnit::Fetch(FetchBuffer *fetch_buffer,
 		// be fetched.
 		if (wavefront->getFinished())
 		{
-			Timing::pipeline_debug << misc::fmt(
-					"wg=%d/wf=%d "
-					"Fetch:Finished\n",
-					wavefront->getWorkGroup()->getId(),
-					wavefront->getId());
 			continue;
 		}
 
 		// Wavefront is ready but waiting on outstanding
 		// memory instructions
-		if (wavefront->isMemoryWait())
+		if (wavefront_pool_entry->mem_wait)
 		{
 			// No outstanding accesses
 			if (!wavefront_pool_entry->lgkm_cnt &&
 				!wavefront_pool_entry->exp_cnt &&
 				!wavefront_pool_entry->vm_cnt)
 			{
-					wavefront->setMemoryWait(false);
+					wavefront_pool_entry->mem_wait = false;
 					Timing::pipeline_debug << misc::fmt(
 							"wg=%d/wf=%d "
 							"Mem-wait:Done\n",
@@ -354,17 +349,17 @@ void ComputeUnit::Fetch(FetchBuffer *fetch_buffer,
 			// Debug
 			Timing::pipeline_debug << misc::fmt(
 					"wg=%d/wf=%d cu=%d wfPool=%d "
-					"InstID=%lld asm=%s id_in_wf=%lld\n"
-					"\tInstID=%lld (Fetch)\n",
+					"inst=%lld asm=%s id_in_wf=%lld\n"
+					"\tinst=%lld (Fetch)\n",
 					uop->getWavefront()->getWorkGroup()->
 					getId(),
 					uop->getWavefront()->getId(),
 					index,
 					uop->getWavefrontPoolId(),
-					uop->getIdInComputeUnit(),
+					uop->getId(),
 					instruction_name.c_str(),
 					uop->getIdInWavefront(),
-					uop->getIdInComputeUnit());
+					uop->getId());
 		}
 
 		// Update last memory accesses
@@ -407,6 +402,7 @@ void ComputeUnit::Fetch(FetchBuffer *fetch_buffer,
 		uop->fetch_ready = timing->getCycle() + fetch_latency;
 
 		// Insert uop into fetch buffer
+		uop->getWorkGroup()->inflight_instructions++;
 		fetch_buffer->addUop(std::move(uop));
 
 		instructions_processed++;
@@ -529,6 +525,8 @@ void ComputeUnit::AddWorkGroup(WorkGroup *work_group)
 	{
 		// Make sure an entry is emptied up
 		assert(work_groups[index] == nullptr);
+		assert(work_groups.size() <=
+				(unsigned) gpu->getWorkGroupsPerComputeUnit());
 
 		// Set the new work group to the empty entry
 		work_groups[index] = work_group;
@@ -581,10 +579,6 @@ void ComputeUnit::UnmapWorkGroup(WorkGroup *work_group)
 	// Unmap wavefronts from instruction buffer
 	work_group->wavefront_pool->UnmapWavefronts(work_group);
 
-	// Remove the work group from the running work groups list
-	NDRange *ndrange = work_group->getNDRange();
-	ndrange->RemoveWorkGroup(work_group);
-
 	// If compute unit is not already in the available list, place
 	// it there. The vector list of work groups does not shrink,
 	// when we unmap a workgroup.
@@ -595,6 +589,10 @@ void ComputeUnit::UnmapWorkGroup(WorkGroup *work_group)
 	// Trace
 	Timing::trace << misc::fmt("si.unmap_wg cu=%d wg=%d\n", index,
 			work_group->getId());
+
+	// Remove the work group from the running work groups list
+	NDRange *ndrange = work_group->getNDRange();
+	ndrange->RemoveWorkGroup(work_group);
 }
 
 

src/arch/southern-islands/timing/ExecutionUnit.cc

@@ -17,10 +17,12 @@
  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
+#include <arch/southern-islands/emulator/WorkGroup.h>
+#include <arch/southern-islands/emulator/Wavefront.h>
+
 #include "BranchUnit.h"
 #include "Timing.h"
 
-
 namespace SI
 {
 

src/arch/southern-islands/timing/LdsUnit.cc

@@ -17,6 +17,7 @@
  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
+#include <arch/southern-islands/emulator/WorkGroup.h>
 #include <arch/southern-islands/emulator/Wavefront.h>
 #include <arch/southern-islands/emulator/WorkItem.h>
 
@@ -109,6 +110,10 @@ void LdsUnit::Complete()
 
 		// Access complete, remove the uop from the queue
 		it = write_buffer.erase(it);
+		assert(uop->getWorkGroup()
+				->inflight_instructions > 0);
+		uop->getWorkGroup()->
+				inflight_instructions--;
 
 		// Statistics
 		num_instructions++;

src/arch/southern-islands/timing/ScalarUnit.cc

@@ -150,14 +150,18 @@ void ScalarUnit::Complete()
 			uop->getWavefrontPoolEntry()->lgkm_cnt--;
 		}
 
+		if (!uop->scalar_memory_read)
+		{
+			// Update wavefront pool entry
+			uop->getWavefrontPoolEntry()->ready = true;
+		}
 
 		// Check for "wait" instruction
 		// If a wait instruction was executed and there are outstanding
 		// memory accesses, set the wavefront to waiting
 		if (uop->memory_wait)
 		{
 			uop->getWavefrontPoolEntry()->mem_wait = true;
-			uop->getWavefrontPoolEntry()->ready = true;
 		}
 
 		// Check for "barrier" instruction
@@ -179,16 +183,7 @@ void ScalarUnit::Complete()
 				assert(wavefront->getWavefrontPoolEntry());
 				if (!wavefront->getWavefrontPoolEntry()->
 						wait_for_barrier)
-				{
-					Timing::pipeline_debug << misc::fmt(
-							"\tInstID=%lld id_in_wf=%lld "
-							"at Barrier:wait for wf=%d\n",
-							uop->getIdInComputeUnit(),
-							uop->getIdInWavefront(),
-							wavefront->
-							getId());
 					barrier_complete = false;
-				}
 			}
 
 			// If all wavefronts have reached the barrier,
@@ -214,9 +209,6 @@ void ScalarUnit::Complete()
 						uop->getIdInWavefront(),
 						uop->getWavefront()->getId());
 			}
-
-			// Update wavefront pool entry
-			uop->getWavefrontPoolEntry()->ready = true;
 		}
 
 		if (uop->wavefront_last_instruction)
@@ -239,8 +231,15 @@ void ScalarUnit::Complete()
 
 			// Check if the work group is finished. If so, unmap
 			// the work group
-			if (work_group->finished_timing)
+			if (work_group->finished_timing &&
+					work_group->inflight_instructions == 1)
+			{
+				Timing::pipeline_debug << misc::fmt(
+						"wg=%d "
+						"WGFinished\n",
+						work_group->getId());
 				compute_unit->UnmapWorkGroup(uop->getWorkGroup());
+			}
 		}
 
 		// Trace
@@ -252,6 +251,8 @@ void ScalarUnit::Complete()
 
 		// Access complete, remove the uop from the queue
 		it = write_buffer.erase(it);
+		assert(uop->getWorkGroup()->inflight_instructions > 0);
+		uop->getWorkGroup()->inflight_instructions--;
 
 		// Statistics
 		num_instructions++;
@@ -639,12 +640,6 @@ void ScalarUnit::Read()
 		uop->read_ready = compute_unit->getTiming()->getCycle() +
 				read_latency;
 
-		if (!uop->at_barrier && !uop->memory_wait &&
-				!uop->wavefront_last_instruction)
-		{
-			uop->getWavefrontPoolEntry()->ready_next_cycle = true;
-		}
-
 		// Trace
 		Timing::trace << misc::fmt("si.inst "
 				"id=%lld "

src/arch/southern-islands/timing/SimdUnit.cc

@@ -17,6 +17,7 @@
  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
+#include <arch/southern-islands/emulator/WorkGroup.h>
 #include <arch/southern-islands/emulator/Wavefront.h>
 
 #include "SimdUnit.h"
@@ -111,6 +112,10 @@ void SimdUnit::Complete()
 		// Remove uop from the exec buffer and get the iterator to the
 		// next element
 		it = exec_buffer.erase(it);
+		assert(uop->getWorkGroup()
+				->inflight_instructions > 0);
+		uop->getWorkGroup()->
+				inflight_instructions--;
 	}
 
 }

src/arch/southern-islands/timing/VectorMemoryUnit.cc

@@ -114,6 +114,10 @@ void VectorMemoryUnit::Complete()
 		// Access complete, remove the uop from the queue and get the 
 		// iterator for the next element
 		it = write_buffer.erase(it);
+		assert(uop->getWorkGroup()
+				->inflight_instructions > 0);
+		uop->getWorkGroup()->
+				inflight_instructions--;
 
 		// Statistics
 		num_instructions++;
@@ -302,6 +306,14 @@ void VectorMemoryUnit::Memory()
 
 		// Access global memory
 		assert(!uop->global_memory_witness);
+		Timing::pipeline_debug << misc::fmt(
+				"\t\t@%lld inst=%lld "
+				"id_in_wf=%lld wg=%d/wf=%d (VecMem)\n",
+				compute_unit->getTiming()->getCycle(),
+				uop->getId(),
+				uop->getIdInWavefront(),
+				uop->getWorkGroup()->getId(),
+				uop->getWavefront()->getId());
 		for (auto wi_it = uop->getWavefront()->getWorkItemsBegin(),
 				wi_e = uop->getWavefront()->getWorkItemsEnd();
 				wi_it != wi_e;

src/arch/southern-islands/timing/WavefrontPool.h

@@ -73,7 +73,6 @@ class WavefrontPoolEntry
 	/// Return the associated wavefront
 	Wavefront *getWavefront() const { return wavefront; }
 
-	
 
 
 	//