GPU TPC: Use stored field value during TPC track model decoding (#15170)

Author: davidrohr

GPU/GPUTracking/Base/GPUParam.h

@@ -80,10 +80,10 @@ struct GPUParam_t {
 struct GPUParam : public internal::GPUParam_t<GPUSettingsRec, GPUSettingsParam> {
 
 #ifndef GPUCA_GPUCODE
-  void SetDefaults(float solenoidBz, bool assumeConstantBz);
+  void SetDefaults(float solenoidBz, bool assumeConstantBz = false);
   void SetDefaults(const GPUSettingsGRP* g, const GPUSettingsRec* r = nullptr, const GPUSettingsProcessing* p = nullptr, const GPURecoStepConfiguration* w = nullptr);
   void UpdateSettings(const GPUSettingsGRP* g, const GPUSettingsProcessing* p = nullptr, const GPURecoStepConfiguration* w = nullptr, const GPUSettingsRecDynamic* d = nullptr);
-  void UpdateBzOnly(float newSolenoidBz, bool assumeConstantBz);
+  void UpdateBzOnly(float newSolenoidBz, bool assumeConstantBz = false);
   void UpdateRun3ClusterErrors(const float* yErrorParam, const float* zErrorParam);
 #endif
 

GPU/GPUTracking/Base/GPUReconstruction.cxx

@@ -433,11 +433,11 @@ int32_t GPUReconstruction::InitPhaseAfterDevice()
   return 0;
 }
 
-void GPUReconstruction::WriteConstantParams()
+void GPUReconstruction::WriteConstantParams(int32_t stream)
 {
   if (IsGPU()) {
     const auto threadContext = GetThreadContext();
-    WriteToConstantMemory(ptrDiff(&processors()->param, processors()), &param(), sizeof(param()), -1);
+    WriteToConstantMemory(ptrDiff(&processors()->param, processors()), &param(), sizeof(param()), stream);
   }
 }
 

GPU/GPUTracking/Base/GPUReconstruction.h

@@ -260,7 +260,7 @@ class GPUReconstruction
   virtual int32_t InitDevice() = 0;
   int32_t InitPhasePermanentMemory();
   int32_t InitPhaseAfterDevice();
-  void WriteConstantParams();
+  void WriteConstantParams(int32_t stream = -1);
   virtual int32_t ExitDevice() = 0;
   virtual size_t WriteToConstantMemory(size_t offset, const void* src, size_t size, int32_t stream = -1, gpu_reconstruction_kernels::deviceEvent* ev = nullptr) = 0;
   void UpdateMaxMemoryUsed();

GPU/GPUTracking/Global/GPUChain.h

@@ -124,6 +124,7 @@ class GPUChain
   inline void TransferMemoryResourceLinkToGPU(RecoStep step, int16_t res, int32_t stream = -1, deviceEvent* ev = nullptr, deviceEvent* evList = nullptr, int32_t nEvents = 1) { timeCpy(step, true, &GPUReconstructionCPU::TransferMemoryResourceLinkToGPU, res, stream, ev, evList, nEvents); }
   inline void TransferMemoryResourceLinkToHost(RecoStep step, int16_t res, int32_t stream = -1, deviceEvent* ev = nullptr, deviceEvent* evList = nullptr, int32_t nEvents = 1) { timeCpy(step, false, &GPUReconstructionCPU::TransferMemoryResourceLinkToHost, res, stream, ev, evList, nEvents); }
   // Todo: retrieve step from proc, move kernelClass->GetStep to retrieve it from GetProcessor
+  inline void WriteConstantParams(int32_t stream = -1) { mRec->WriteConstantParams(stream); }
   inline void WriteToConstantMemory(RecoStep step, size_t offset, const void* src, size_t size, int32_t stream = -1, deviceEvent* ev = nullptr) { timeCpy(step, true, &GPUReconstructionCPU::WriteToConstantMemory, offset, src, size, stream, ev); }
   inline void GPUMemCpy(RecoStep step, void* dst, const void* src, size_t size, int32_t stream, int32_t toGPU, deviceEvent* ev = nullptr, deviceEvent* evList = nullptr, int32_t nEvents = 1) { timeCpy(step, toGPU, &GPUReconstructionCPU::GPUMemCpy, dst, src, size, stream, toGPU, ev, evList, nEvents); }
   inline void GPUMemCpyAlways(RecoStep step, void* dst, const void* src, size_t size, int32_t stream, int32_t toGPU, deviceEvent* ev = nullptr, deviceEvent* evList = nullptr, int32_t nEvents = 1)

GPU/GPUTracking/Global/GPUChainTrackingCompression.cxx

@@ -225,6 +225,17 @@ int32_t GPUChainTracking::RunTPCDecompression()
     GPUFatal("tpcApplyCFCutsAtDecoding, tpcApplyClusterFilterOnCPU and tpcCutTimeBin currently require tpcUseOldCPUDecoding");
   }
 
+  CompressedClusters cmprClsHost = *mIOPtrs.tpcCompressedClusters;
+  const bool useTemporaryBz = cmprClsHost.nTracks && cmprClsHost.solenoidBz != -1e6f && cmprClsHost.solenoidBz != param().bzkG && !GetProcessingSettings().doublePipeline;
+  std::unique_ptr<GPUParam> tmpParam;
+  int32_t inputStream = 0;
+
+  if (useTemporaryBz) {
+    tmpParam = std::make_unique<GPUParam>(param());
+    SynchronizeGPU();
+    param().UpdateBzOnly(cmprClsHost.solenoidBz, mRec->GetGRPSettings().constBz);
+    WriteConstantParams(inputStream);
+  }
   if (GetProcessingSettings().tpcUseOldCPUDecoding) {
     const bool runFiltering = needFullFiltering || runTimeBinCutFiltering;
     const auto& threadContext = GetThreadContext();
@@ -268,7 +279,6 @@ int32_t GPUChainTracking::RunTPCDecompression()
     GPUTPCDecompression& Decompressor = processors()->tpcDecompressor;
     GPUTPCDecompression& DecompressorShadow = doGPU ? processorsShadow()->tpcDecompressor : Decompressor;
     const auto& threadContext = GetThreadContext();
-    CompressedClusters cmprClsHost = *mIOPtrs.tpcCompressedClusters;
     CompressedClusters& inputGPU = Decompressor.mInputGPU;
     CompressedClusters& inputGPUShadow = DecompressorShadow.mInputGPU;
 
@@ -279,7 +289,6 @@ int32_t GPUChainTracking::RunTPCDecompression()
       throw std::runtime_error("Configured max time bin does not match value used for track model encoding");
     }
 
-    int32_t inputStream = 0;
     int32_t unattachedStream = mRec->NStreams() - 1;
     inputGPU = cmprClsHost;
     SetupGPUProcessor(&Decompressor, true);
@@ -437,6 +446,12 @@ int32_t GPUChainTracking::RunTPCDecompression()
     }
     mRec->PopNonPersistentMemory(RecoStep::TPCDecompression, qStr2Tag("TPCDCMPR"));
   }
+  if (useTemporaryBz) {
+    SynchronizeGPU();
+    param() = *tmpParam;
+    tmpParam.reset();
+    WriteConstantParams();
+  }
   DoDebugDump(GPUChainTrackingDebugFlags::TPCDecompressedClusters, &GPUChainTracking::DumpClusters, *mDebugFile, mIOPtrs.clustersNative);
   return 0;
 }

GPU/GPUTracking/Interface/GPUO2InterfaceRefit.cxx

@@ -129,7 +129,7 @@ GPUO2InterfaceRefit::GPUO2InterfaceRefit(const ClusterNativeAccess* cl, const Co
 
 void GPUO2InterfaceRefit::updateCalib(const CorrectionMapsHelper* trans, float bzNominalGPU)
 {
-  mParam->UpdateBzOnly(bzNominalGPU, false);
+  mParam->UpdateBzOnly(bzNominalGPU);
   mRefit->SetFastTransformHelper(trans);
 }
 

GPU/GPUTracking/Interface/GPUO2InterfaceUtils.cxx

@@ -52,7 +52,7 @@ template <>
 void GPUO2InterfaceUtils::RunZSEncoder<DigitArray>(const DigitArray& in, std::unique_ptr<uint64_t[]>* outBuffer, uint32_t* outSizes, o2::raw::RawFileWriter* raw, const o2::InteractionRecord* ir, int32_t version, bool verify, float threshold, bool padding, std::function<void(std::vector<o2::tpc::Digit>&)> digitsFilter)
 {
   GPUParam param;
-  param.SetDefaults(5.00668, false);
+  param.SetDefaults(5.00668);
   o2::gpu::GPUReconstructionConvert::RunZSEncoder(in, outBuffer, outSizes, raw, ir, param, version, verify, threshold, padding, digitsFilter);
 }
 template <>