Revert "GPU TPC: Remove option to retry refit if cluster rejection breaks the track, we will anyway rebuild the track in the future"

This reverts commit 5c3d113.

We can actually properly retry also for rebuilt tracks, we just run the retry on the last iteration after rebuilding.

Author: davidrohr

GPU/GPUTracking/Definitions/GPUSettingsList.h

@@ -160,6 +160,7 @@ AddOptionRTC(mergerInterpolateErrors, uint8_t, 1, "", 0, "Use interpolation inst
 AddOptionRTC(mergerInterpolateRejectAlsoOnCurrentPosition, uint8_t, 1, "", 0, "When using mergerInterpolateErrors, reject based on chi2 twice computed with interpolated and current track position starting from NDF > mergerNonInterpolateRejectMinNDF")
 AddOptionRTC(mergerNonInterpolateRejectMinNDF, uint8_t, 5, "", 0, "Minimum NDF of track for non-interpolated reject (both for chi2 and absolute distance)")
 AddOptionRTC(mergeCE, uint8_t, 1, "", 0, "Merge tracks accross the central electrode")
+AddOptionRTC(retryRefit, int8_t, 1, "", 0, "Retry refit with seeding errors and without cluster rejection when fit fails")
 AddOptionRTC(enablePID, int8_t, 1, "", 0, "Enable PID response")
 AddOptionRTC(PID_useNsigma, int8_t, 1, "", 0, "Use nSigma instead of absolute distance in PID response")
 AddOptionRTC(adddEdxSubThresholdClusters, int8_t, 1, "", 0, "Add sub threshold clusters in TPC dEdx computation")

GPU/GPUTracking/Global/GPUChainTrackingMerger.cxx

@@ -240,6 +240,10 @@ int32_t GPUChainTracking::RunTPCTrackingMerger(bool synchronizeOutput)
     DoDebugAndDump(RecoStep::TPCMerging, GPUChainTrackingDebugFlags::TPCMergingRefit, Merger, &GPUTPCGMMerger::DumpRebuiltTracks, *mDebugFile);
     runKernel<GPUTPCGMMergerTrackFit>(doGPU ? GetGrid(Merger.NMergedTracks(), 0) : GetGridAuto(0), mergerSortTracks ? 1 : 0, 1);
   }
+  if (param().rec.tpc.retryRefit) {
+    runKernel<GPUTPCGMMergerTrackFit>(GetGridAuto(0), -1, param().rec.tpc.rebuildTrackInFit);
+  }
+
   runKernel<GPUTPCGMMergerFollowLoopers>(GetGridAuto(0));
 
   DoDebugAndDump(RecoStep::TPCMerging, GPUChainTrackingDebugFlags::TPCMergingRefit, Merger, &GPUTPCGMMerger::DumpRefit, *mDebugFile);

GPU/GPUTracking/Merger/GPUTPCGMMerger.cxx

@@ -402,13 +402,16 @@ void* GPUTPCGMMerger::SetPointersMerger(void* mem)
   computePointerWithAlignment(mem, mTrackSort, mNMaxTracks);
   memMax = (void*)std::max((size_t)mem, (size_t)memMax);
   mem = memBase;
-  computePointerWithAlignment(mem, mLoopData, mNMaxTracks); // GPUTPCGMMergerTrackFit - GPUTPCGMMergerFollowLoopers, Reducing mNMaxTracks for mLoopData does not save memory, other parts are larger anyway
+  computePointerWithAlignment(mem, mLoopData, mNMaxTracks); // GPUTPCGMMergerTrackFit - GPUTPCGMMergerFollowLoopers, Reducing mNMaxTracks does not save memory, other parts are larger anyway
   if (mRec->GetParam().rec.tpc.rebuildTrackInFit) {
     computePointerWithAlignment(mem, mSharedCount2, mNClusters);
     computePointerWithAlignment(mem, mClusterCandidates, mNMaxTracks * GPUCA_ROW_COUNT * mRec->GetParam().rec.tpc.rebuildTrackInFitClusterCandidates);
     computePointerWithAlignment(mem, mTrackRebuildHelper, mNMaxTracks);
     computePointerWithAlignment(mem, mHitWeights, mNClusters);
   }
+  if (mRec->GetParam().rec.tpc.retryRefit) {
+    computePointerWithAlignment(mem, mRetryRefitIds, mNMaxTracks);
+  }
   memMax = (void*)std::max((size_t)mem, (size_t)memMax);
   mem = memBase;
   computePointerWithAlignment(mem, mLooperCandidates, mNMaxLooperMatches); // MergeLoopers 1-3

GPU/GPUTracking/Merger/GPUTPCGMMerger.h

@@ -66,6 +66,7 @@ class GPUTPCGMMerger : public GPUProcessor
   static constexpr const int32_t NSECTORS = GPUCA_NSECTORS; //* N sectors
 
   struct memory {
+    GPUAtomic(uint32_t) nRetryRefit;
     GPUAtomic(uint32_t) nLoopData;
     GPUAtomic(uint32_t) nUnpackedTracks;
     GPUAtomic(uint32_t) nMergedTracks;
@@ -130,6 +131,7 @@ class GPUTPCGMMerger : public GPUProcessor
   GPUhdi() GPUAtomic(uint32_t) * ClusterAttachment() const { return mClusterAttachment; }
   GPUhdi() uint32_t* TrackOrderAttach() const { return mTrackOrderAttach; }
   GPUhdi() uint32_t* TrackOrderProcess() const { return mTrackOrderProcess; }
+  GPUhdi() uint32_t* RetryRefitIds() const { return mRetryRefitIds; }
   GPUhdi() uint8_t* ClusterStateExt() const { return mClusterStateExt; }
   GPUhdi() GPUTPCGMLoopData* LoopData() const { return mLoopData; }
   GPUhdi() memory* Memory() const { return mMemory; }
@@ -312,6 +314,7 @@ class GPUTPCGMMerger : public GPUProcessor
   gputpcgmmergertypes::GPUTPCGMBorderRange* mBorderRangeMemory = nullptr; // memory for border tracks
   gputpcgmmergertypes::GPUTPCGMBorderRange* mBorderRange[NSECTORS];       // memory for border tracks
   memory* mMemory = nullptr;
+  uint32_t* mRetryRefitIds = nullptr;
   GPUTPCGMLoopData* mLoopData = nullptr;
 };
 } // namespace o2::gpu

GPU/GPUTracking/Merger/GPUTPCGMMergerGPU.cxx

@@ -21,9 +21,10 @@ using namespace o2::gpu;
 template <>
 GPUdii() void GPUTPCGMMergerTrackFit::Thread<0>(int32_t nBlocks, int32_t nThreads, int32_t iBlock, int32_t iThread, GPUsharedref() GPUSharedMemory& smem, processorType& GPUrestrict() merger, int32_t mode, int32_t rebuilt)
 {
-  GPUCA_TBB_KERNEL_LOOP(merger.GetRec(), int32_t, ii, merger.NMergedTracks(), {
-    const int32_t i = mode ? merger.TrackOrderProcess()[ii] : ii;
-    GPUTPCGMTrackParam::RefitTrack(merger.MergedTracks()[i], i, merger, rebuilt);
+  const int32_t iEnd = mode == -1 ? merger.Memory()->nRetryRefit : merger.NMergedTracks();
+  GPUCA_TBB_KERNEL_LOOP(merger.GetRec(), int32_t, ii, iEnd, {
+    const int32_t i = mode == -1 ? merger.RetryRefitIds()[ii] : (mode ? merger.TrackOrderProcess()[ii] : ii);
+    GPUTPCGMTrackParam::RefitTrack(merger.MergedTracks()[i], i, merger, rebuilt, mode == -1);
   });
 }
 

GPU/GPUTracking/Merger/GPUTPCGMTrackParam.cxx

@@ -48,7 +48,7 @@
 using namespace o2::gpu;
 using namespace o2::tpc;
 
-GPUd() bool GPUTPCGMTrackParam::Fit(GPUTPCGMMerger& GPUrestrict() merger, int32_t iTrk, int32_t& GPUrestrict() N, int32_t& GPUrestrict() NTolerated, float& GPUrestrict() Alpha, GPUTPCGMMergedTrack& GPUrestrict() track, bool rebuilt)
+GPUd() bool GPUTPCGMTrackParam::Fit(GPUTPCGMMerger& GPUrestrict() merger, int32_t iTrk, int32_t& GPUrestrict() N, int32_t& GPUrestrict() NTolerated, float& GPUrestrict() Alpha, GPUTPCGMMergedTrack& GPUrestrict() track, bool rebuilt, bool retryAttempt)
 {
   static constexpr float maxSinPhi = GPUCA_MAX_SIN_PHI;
 
@@ -92,7 +92,7 @@ GPUd() bool GPUTPCGMTrackParam::Fit(GPUTPCGMMerger& GPUrestrict() merger, int32_
     const bool finalFit = iWay == nWays - 1;
 
     ResetCovariance();
-    prop.SetSeedingErrors(!(refit));
+    prop.SetSeedingErrors(!(refit && !retryAttempt));
     prop.SetFitInProjections(true); // param.rec.fitInProjections == -1 ? (iWay == 0) : param.rec.fitInProjections); // TODO: Reenable once fixed
     prop.SetPropagateBzOnly(param.rec.fitPropagateBzOnly == -1 ? !finalFit : param.rec.fitPropagateBzOnly);
     prop.SetMatLUT((param.rec.useMatLUT && finalFit) ? merger.GetConstantMem()->calibObjects.matLUT : nullptr);
@@ -240,7 +240,7 @@ GPUd() bool GPUTPCGMTrackParam::Fit(GPUTPCGMMerger& GPUrestrict() merger, int32_
         continue;
       }
 
-      int32_t retValHit = FitHit(merger, iTrk, track, xx, yy, zz, clusterState, clAlpha, iWay, inFlyDirection, deltaZ, lastUpdateX, clusters, prop, inter, dEdx, dEdxAlt, sumInvSqrtCharge, nAvgCharge, ihit, ihitMergeFirst, allowChangeClusters, refit, finalFit, nMissed, nMissed2, resetT0, uncorrectedY);
+      int32_t retValHit = FitHit(merger, iTrk, track, xx, yy, zz, clusterState, clAlpha, iWay, inFlyDirection, deltaZ, lastUpdateX, clusters, prop, inter, dEdx, dEdxAlt, sumInvSqrtCharge, nAvgCharge, ihit, ihitMergeFirst, allowChangeClusters, refit, finalFit, nMissed, nMissed2, resetT0, uncorrectedY, retryAttempt);
       if (retValHit == 0) {
         DodEdx(dEdx, dEdxAlt, merger, finalFit, ihit, ihitMergeFirst, wayDirection, clusters, clusterState, zz, dEdxSubThresholdRow);
         ihitStart = ihit;
@@ -257,7 +257,7 @@ GPUd() bool GPUTPCGMTrackParam::Fit(GPUTPCGMMerger& GPUrestrict() merger, int32_
       lastUpdateRow = cluster.row;
       assert(!param.rec.tpc.mergerInterpolateErrors || rebuilt || iWay != nWays - 2 || ihit || interpolationIndex == 0);
     }
-    if (finalOutInFit && !(param.rec.tpc.disableRefitAttachment & 4) && lastUpdateRow != 255) {
+    if (finalOutInFit && !(param.rec.tpc.disableRefitAttachment & 4) && lastUpdateRow != 255 && !retryAttempt) {
       StoreLoopPropagation(merger, lastSector, lastUpdateRow, iTrk, lastUpdateRow > clusters[(iWay & 1) ? (maxN - 1) : 0].row, prop.GetAlpha());
       CADEBUG(printf("\t\tSTORING %d lastUpdateRow %d row %d out %d\n", iTrk, (int)lastUpdateRow, (int)clusters[(iWay & 1) ? (maxN - 1) : 0].row, lastUpdateRow > clusters[(iWay & 1) ? (maxN - 1) : 0].row));
     }
@@ -348,7 +348,7 @@ GPUdii() void GPUTPCGMTrackParam::HandleCrossCE(const GPUParam& GPUrestrict() pa
   }
 }
 
-GPUdii() int32_t GPUTPCGMTrackParam::FitHit(GPUTPCGMMerger& GPUrestrict() merger, const int32_t iTrk, const GPUTPCGMMergedTrack& GPUrestrict() track, const float xx, const float yy, const float zz, const uint8_t clusterState, const float clAlpha, const int32_t iWay, const bool inFlyDirection, float& GPUrestrict() deltaZ, float& GPUrestrict() lastUpdateX, GPUTPCGMMergedTrackHit* GPUrestrict() clusters, GPUTPCGMPropagator& GPUrestrict() prop, gputpcgmmergertypes::InterpolationErrorHit& GPUrestrict() inter, GPUdEdx& GPUrestrict() dEdx, GPUdEdx& GPUrestrict() dEdxAlt, float& GPUrestrict() sumInvSqrtCharge, int32_t& GPUrestrict() nAvgCharge, const int32_t ihit, const int32_t ihitMergeFirst, const bool allowChangeClusters, const bool refit, const bool finalFit, int32_t& GPUrestrict() nMissed, int32_t& GPUrestrict() nMissed2, int32_t& GPUrestrict() resetT0, float uncorrectedY)
+GPUdii() int32_t GPUTPCGMTrackParam::FitHit(GPUTPCGMMerger& GPUrestrict() merger, const int32_t iTrk, const GPUTPCGMMergedTrack& GPUrestrict() track, const float xx, const float yy, const float zz, const uint8_t clusterState, const float clAlpha, const int32_t iWay, const bool inFlyDirection, float& GPUrestrict() deltaZ, float& GPUrestrict() lastUpdateX, GPUTPCGMMergedTrackHit* GPUrestrict() clusters, GPUTPCGMPropagator& GPUrestrict() prop, gputpcgmmergertypes::InterpolationErrorHit& GPUrestrict() inter, GPUdEdx& GPUrestrict() dEdx, GPUdEdx& GPUrestrict() dEdxAlt, float& GPUrestrict() sumInvSqrtCharge, int32_t& GPUrestrict() nAvgCharge, const int32_t ihit, const int32_t ihitMergeFirst, const bool allowChangeClusters, const bool refit, const bool finalFit, int32_t& GPUrestrict() nMissed, int32_t& GPUrestrict() nMissed2, int32_t& GPUrestrict() resetT0, float uncorrectedY, bool retryAttempt)
 {
   const GPUParam& GPUrestrict() param = merger.Param();
   const int32_t nWays = param.rec.tpc.nWays;
@@ -372,23 +372,25 @@ GPUdii() int32_t GPUTPCGMTrackParam::FitHit(GPUTPCGMMerger& GPUrestrict() merger
 
     prop.GetErr2(err2Y, err2Z, param, zz, cluster.row, clusterState, cluster.sector, time, invAvgCharge, invCharge);
 
-    bool rejectChi2 = (clusterState & GPUTPCGMMergedTrackHit::flagReject);
-    if (param.rec.tpc.mergerInterpolateErrors) {
-      if (iWay == nWays - 2) {
-        if (!param.rec.tpc.rebuildTrackInFit) {
-          if (inter.isValid()) {
-            retValInt = prop.InterpolateReject(param, yy, zz, clusterState, &inter, err2Y, err2Z, deltaZ);
-          } else {
+    bool rejectChi2 = !retryAttempt && (clusterState & GPUTPCGMMergedTrackHit::flagReject);
+    if (!retryAttempt) {
+      if (param.rec.tpc.mergerInterpolateErrors) {
+        if (iWay == nWays - 2) {
+          if (!param.rec.tpc.rebuildTrackInFit) {
+            if (inter.isValid()) {
+              retValInt = prop.InterpolateReject(param, yy, zz, clusterState, &inter, err2Y, err2Z, deltaZ);
+            } else {
+              rejectChi2 = true;
+            }
+          }
+        } else if (iWay == nWays - 1) {
+          if (param.rec.tpc.mergerInterpolateRejectAlsoOnCurrentPosition && GetNDF() > (int32_t)param.rec.tpc.mergerNonInterpolateRejectMinNDF) {
             rejectChi2 = true;
           }
         }
-      } else if (iWay == nWays - 1) {
-        if (param.rec.tpc.mergerInterpolateRejectAlsoOnCurrentPosition && GetNDF() > (int32_t)param.rec.tpc.mergerNonInterpolateRejectMinNDF) {
-          rejectChi2 = true;
-        }
+      } else {
+        rejectChi2 = allowChangeClusters;
       }
-    } else {
-      rejectChi2 = allowChangeClusters;
     }
 
     if (param.rec.tpc.rejectEdgeClustersInTrackFit && uncorrectedY > -1e6f && param.rejectEdgeClusterByY(uncorrectedY, cluster.row, CAMath::Sqrt(mC[0]))) {
@@ -894,6 +896,10 @@ GPUdic(0, 1) void GPUTPCGMTrackParam::StoreLoopPropagation(const GPUTPCGMMerger&
 
 GPUdii() void GPUTPCGMTrackParam::PropagateLooper(const GPUTPCGMMerger& GPUrestrict() merger, int32_t loopIdx)
 {
+  GPUTPCGMLoopData& data = merger.LoopData()[loopIdx];
+  if (!merger.MergedTracks()[data.track].OK()) {
+    return;
+  }
   GPUTPCGMPropagator prop;
   prop.SetMaterialTPC();
   prop.SetPolynomialField(&merger.Param().polynomialField);
@@ -903,7 +909,6 @@ GPUdii() void GPUTPCGMTrackParam::PropagateLooper(const GPUTPCGMMerger& GPUrestr
   prop.SetFitInProjections(true);
   prop.SetPropagateBzOnly(false);
 
-  GPUTPCGMLoopData& data = merger.LoopData()[loopIdx];
   prop.SetTrack(&data.param, data.alpha);
   if (merger.Param().rec.tpc.looperFollowMode == 1) {
     data.param.AttachClustersLooperFollow(merger, prop, data.sector, data.row, data.track, data.outwards);
@@ -1142,7 +1147,7 @@ GPUd() bool GPUTPCGMTrackParam::CheckNumericalQuality(float overrideCovYY) const
   return ok;
 }
 
-GPUdii() void GPUTPCGMTrackParam::RefitTrack(GPUTPCGMMergedTrack& GPUrestrict() track, int32_t iTrk, GPUTPCGMMerger& GPUrestrict() merger, bool rebuilt) // VS: GPUd changed to GPUdii. No change in output and no performance penalty.
+GPUdii() void GPUTPCGMTrackParam::RefitTrack(GPUTPCGMMergedTrack& GPUrestrict() track, int32_t iTrk, GPUTPCGMMerger& GPUrestrict() merger, bool rebuilt, bool retryAttempt)
 {
   if (!track.OK()) {
     return;
@@ -1154,16 +1159,29 @@ GPUdii() void GPUTPCGMTrackParam::RefitTrack(GPUTPCGMMergedTrack& GPUrestrict()
   int32_t NTolerated = 0; // Clusters not fit but tollerated for track length cut
   GPUTPCGMTrackParam t = track.Param();
   float Alpha = track.Alpha();
-  bool ok = t.Fit(merger, iTrk, nTrackHits, NTolerated, Alpha, track, rebuilt);
+  bool ok = t.Fit(merger, iTrk, nTrackHits, NTolerated, Alpha, track, rebuilt, retryAttempt);
   CADEBUG(if (!merger.Param().rec.tpc.rebuildTrackInFit || rebuilt) printf("Finished Fit Track %7d --- OUTPUT hits %d -> %d+%d = %d, QPt %f -> %f, SP %f, OK %d chi2 %f chi2ndf %f\n", iTrk, track.NClusters(), nTrackHits, NTolerated, nTrackHits + NTolerated, track.GetParam().GetQPt(), t.QPt(), t.SinPhi(), (int32_t)ok, t.Chi2(), t.Chi2() / CAMath::Max(1, nTrackHits)));
 
+  if (!ok && (!merger.Param().rec.tpc.rebuildTrackInFit || rebuilt) && !retryAttempt && merger.Param().rec.tpc.retryRefit) {
+    for (uint32_t i = 0; i < track.NClusters(); i++) {
+      merger.Clusters()[track.FirstClusterRef() + i].state &= GPUTPCGMMergedTrackHit::clustererAndSharedFlags;
+    }
+    CADEBUG(printf("Track rejected, marking for retry\n"));
+    uint32_t nRefit = CAMath::AtomicAdd(&merger.Memory()->nRetryRefit, 1u);
+    merger.RetryRefitIds()[nRefit] = iTrk;
+    return;
+  }
+  if (retryAttempt && (t.mNDF < 10 || t.mChi2 / t.mNDF >= 6.f)) {
+    ok = false;
+  }
+
   if (CAMath::Abs(t.QPt()) < 1.e-4f) {
     t.QPt() = CAMath::Copysign(1.e-4f, t.QPt());
   }
 
   CADEBUG(if (t.GetX() > 250) { printf("ERROR, Track %d at impossible X %f, Pt %f, Looper %d\n", iTrk, t.GetX(), CAMath::Abs(1.f / t.QPt()), (int32_t)merger.MergedTracks()[iTrk].Looper()); });
 
-  track.SetOK(ok);                                                               // TODO: Should we recover tracks who failed the fit in iWay0/1 for the rebuild?
+  track.SetOK(ok);
   if (t.GetNDF() <= 0 && !rebuilt && merger.Param().rec.tpc.rebuildTrackInFit) { // TODO: Better handling of NDF<0 tracks, how do we want to do cluster rejection?
     track.Param().NDF() = 0;
   } else {

GPU/GPUTracking/Merger/GPUTPCGMTrackParam.h

@@ -154,12 +154,12 @@ class GPUTPCGMTrackParam
   GPUd() bool CheckNumericalQuality(float overrideCovYY = -1.f) const;
   GPUd() bool CheckCov() const;
 
-  GPUd() bool Fit(GPUTPCGMMerger& merger, int32_t iTrk, int32_t& N, int32_t& NTolerated, float& Alpha, GPUTPCGMMergedTrack& track, bool rebuilt);
+  GPUd() bool Fit(GPUTPCGMMerger& merger, int32_t iTrk, int32_t& N, int32_t& NTolerated, float& Alpha, GPUTPCGMMergedTrack& track, bool rebuilt, bool retryAttempt);
   GPUd() void DodEdx(GPUdEdx& dEdx, GPUdEdx& dEdxAlt, GPUTPCGMMerger& merger, bool finalFit, int ihit, int ihitMergeFirst, int wayDirection, const GPUTPCGMMergedTrackHit* clusters, uint8_t clusterState, float zz, uint8_t dEdxSubThresholdRow);
-  GPUd() int32_t FitHit(GPUTPCGMMerger& merger, const int32_t iTrk, const GPUTPCGMMergedTrack& track, const float xx, const float yy, const float zz, const uint8_t clusterState, const float clAlpha, const int32_t iWay, const bool inFlyDirection, float& deltaZ, float& lastUpdateX, GPUTPCGMMergedTrackHit* clusters, GPUTPCGMPropagator& prop, gputpcgmmergertypes::InterpolationErrorHit& inter, GPUdEdx& dEdx, GPUdEdx& dEdxAlt, float& sumInvSqrtCharge, int32_t& nAvgCharge, const int32_t ihit, const int32_t ihitMergeFirst, const bool allowChangeClusters, const bool refit, const bool finalFit, int32_t& nMissed, int32_t& nMissed2, int32_t& resetT0, float uncorrectedY);
+  GPUd() int32_t FitHit(GPUTPCGMMerger& merger, const int32_t iTrk, const GPUTPCGMMergedTrack& track, const float xx, const float yy, const float zz, const uint8_t clusterState, const float clAlpha, const int32_t iWay, const bool inFlyDirection, float& deltaZ, float& lastUpdateX, GPUTPCGMMergedTrackHit* clusters, GPUTPCGMPropagator& prop, gputpcgmmergertypes::InterpolationErrorHit& inter, GPUdEdx& dEdx, GPUdEdx& dEdxAlt, float& sumInvSqrtCharge, int32_t& nAvgCharge, const int32_t ihit, const int32_t ihitMergeFirst, const bool allowChangeClusters, const bool refit, const bool finalFit, int32_t& nMissed, int32_t& nMissed2, int32_t& resetT0, float uncorrectedY, bool retryAttempt);
   GPUd() void FitAddRow(const int32_t iRow, const uint8_t sector, const int32_t iTrk, const GPUTPCGMMergedTrack& track, GPUTPCGMPropagator& prop, const bool inFlyDirection, GPUTPCGMMerger& merger, uint8_t* dEdxSubThresholdRow, const bool dodEdx, const bool doAttach, const uint8_t doInterpolate, gputpcgmmergertypes::InterpolationErrorHit& inter, const float deltaZ, const float sumInvSqrtCharge, const int32_t nAvgCharge);
   GPUd() void HandleCrossCE(const GPUParam& param, const uint8_t sector, const uint8_t& lastSector);
-  GPUd() static void RefitTrack(GPUTPCGMMergedTrack& track, int32_t iTrk, GPUTPCGMMerger& merger, bool rebuilt);
+  GPUd() static void RefitTrack(GPUTPCGMMergedTrack& track, int32_t iTrk, GPUTPCGMMerger& merger, bool rebuilt, bool retryAttempt);
   GPUd() void MoveToReference(GPUTPCGMPropagator& prop, const GPUParam& param, float& alpha);
   GPUd() void MirrorTo(GPUTPCGMPropagator& prop, float toY, float toZ, bool inFlyDirection, const GPUParam& param, uint8_t row, uint8_t clusterState, bool mirrorParameters, int8_t sector);
   GPUd() int32_t MergeDoubleRowClusters(int32_t& ihit, int32_t wayDirection, GPUTPCGMMergedTrackHit* clusters, const GPUTPCGMMerger& merger, GPUTPCGMPropagator& prop, float& xx, float& yy, float& zz, int32_t maxN, float clAlpha, uint8_t& clusterState, const bool markReject);

GPU/GPUTracking/qa/GPUQA.cxx

@@ -2906,7 +2906,7 @@ int32_t GPUQA::DrawQAHistograms(TObjArray* qcout)
     }
   }
 
-  if (mQATasks & taskTrackStatistics) {
+  if (mQATasks & taskTrackStatistics) { // TODO: Add plot for Chi2/NDF, and NCl correct and fake MC histograms
     // Process track statistic histograms
     float tmpMax = 0.;
     for (int32_t k = 0; k < ConfigNumInputs; k++) { // TODO: Simplify this drawing, avoid copy&paste