[llvm] [offload] add handling of memory alignment to MemoryManagerTy (PR #218418)

[Jan Trusiłło via llvm-commits]

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@@ -264,32 +281,55 @@ class MemoryManagerTy {
       ODBG(OLDT_Alloc) << "Got target pointer " << *TgtPtrOrErr
                        << ". Return directly.";
 
+      if (Alignment > 0 && !isAddrAligned(Align(Alignment), *TgtPtrOrErr)) {
+        auto AlignErr = make_error<StringError>(
+            "Allocated address is misaligned", inconvertibleErrorCode());
+        if (auto FreeErr = deleteOnDevice(*TgtPtrOrErr)) {
+          return joinErrors(std::move(FreeErr), std::move(AlignErr));
+        }
+
+        return AlignErr;
+      }
+
       return *TgtPtrOrErr;
     }
 
+    if (Alignment > 0) {
+      Size += Alignment - 1;
+    }
     NodeTy *NodePtr = nullptr;
 
     // Try to get a node from FreeList
     {
       const int B = findBucket(Size);
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311Volt wrote:

Note that you added padding to `Size` \*after\* you made the check against threshold to dispatch to direct device alloc. So I can see specific `Size`+`Alignment` combinations where `Size` becomes too big for the pooled case here, depending on how you set the threshold.



https://github.com/llvm/llvm-project/pull/218418