GPU/TPC: Fix row overflow in Pad Filter.

fweig · davidrohr · commit 7a4fd4593117 · 2026-04-23T17:08:50.000+02:00
diff --git a/GPU/GPUTracking/TPCClusterFinder/GPUTPCCFCheckPadBaseline.h b/GPU/GPUTracking/TPCClusterFinder/GPUTPCCFCheckPadBaseline.h
@@ -63,8 +63,10 @@ class GPUTPCCFCheckPadBaseline : public GPUKernelTemplate
 
   static int32_t GetNBlocks(bool isGPU)
   {
-    const int32_t nBlocks = TPC_CLUSTERER_STRIDED_PAD_COUNT / PadsPerCacheline;
-    return isGPU ? GPUTPCGeometry::NROWS : nBlocks;
+    // Important to exclude rightmost padding from Pad Filter.
+    // There's nothing to filter there and padding is counted as start of a row, so it causes an overflow in the row count.
+    const int32_t nBlocksCPU = (TPC_CLUSTERER_STRIDED_PAD_COUNT - GPUCF_PADDING_PAD) / PadsPerCacheline;
+    return isGPU ? GPUTPCGeometry::NROWS : nBlocksCPU;
   }
 
   template <int32_t iKernel = defaultKernel>

Original file line number	Diff line number	Diff line change
`@@ -63,8 +63,10 @@ class GPUTPCCFCheckPadBaseline : public GPUKernelTemplate`
`63`	`63`
`64`	`64`	`static int32_t GetNBlocks(bool isGPU)`
`65`	`65`	`{`
`66`		`- const int32_t nBlocks = TPC_CLUSTERER_STRIDED_PAD_COUNT / PadsPerCacheline;`
`67`		`- return isGPU ? GPUTPCGeometry::NROWS : nBlocks;`
	`66`	`+ // Important to exclude rightmost padding from Pad Filter.`
	`67`	`+ // There's nothing to filter there and padding is counted as start of a row, so it causes an overflow in the row count.`
	`68`	`+ const int32_t nBlocksCPU = (TPC_CLUSTERER_STRIDED_PAD_COUNT - GPUCF_PADDING_PAD) / PadsPerCacheline;`
	`69`	`+ return isGPU ? GPUTPCGeometry::NROWS : nBlocksCPU;`
`68`	`70`	`}`
`69`	`71`
`70`	`72`	`template <int32_t iKernel = defaultKernel>`