GPU TPC: Fix deterministic mode with new cluster removal protection

davidrohr · davidrohr · commit a839182762a0 · 2026-02-21T18:56:16.000+01:00
diff --git a/GPU/GPUTracking/Merger/GPUTPCGMMerger.cxx b/GPU/GPUTracking/Merger/GPUTPCGMMerger.cxx
@@ -1852,7 +1852,7 @@ GPUd() void GPUTPCGMMerger::PrepareForFit1(int32_t nBlocks, int32_t nThreads, in
         if (CAMath::Abs(trk.GetParam().GetQPt() * Param().qptB5Scaler) <= Param().rec.tpc.rejectQPtB5 && !trk.MergedLooper() && trk.Leg() == 0) {
           weight |= attachProtect;
         }
-        mClusterAttachment[mClusters[trk.FirstClusterRef() + j].num] = weight;
+        CAMath::AtomicMax(&mClusterAttachment[mClusters[trk.FirstClusterRef() + j].num], weight);
         CAMath::AtomicAdd(&mSharedCount[mClusters[trk.FirstClusterRef() + j].num], 1u);
       }
       if (!trk.CCE() && !trk.MergedLooper()) {

Original file line number	Diff line number	Diff line change
`@@ -1852,7 +1852,7 @@ GPUd() void GPUTPCGMMerger::PrepareForFit1(int32_t nBlocks, int32_t nThreads, in`
`1852`	`1852`	`if (CAMath::Abs(trk.GetParam().GetQPt() * Param().qptB5Scaler) <= Param().rec.tpc.rejectQPtB5 && !trk.MergedLooper() && trk.Leg() == 0) {`
`1853`	`1853`	`weight \|= attachProtect;`
`1854`	`1854`	`}`
`1855`		`- mClusterAttachment[mClusters[trk.FirstClusterRef() + j].num] = weight;`
	`1855`	`+ CAMath::AtomicMax(&mClusterAttachment[mClusters[trk.FirstClusterRef() + j].num], weight);`
`1856`	`1856`	`CAMath::AtomicAdd(&mSharedCount[mClusters[trk.FirstClusterRef() + j].num], 1u);`
`1857`	`1857`	`}`
`1858`	`1858`	`if (!trk.CCE() && !trk.MergedLooper()) {`