[llvm-branch-commits] [llvm] [offload] Thread allocation kind through async info (PR #214755)

[Robert Imschweiler via llvm-branch-commits]

https://github.com/ro-i created https://github.com/llvm/llvm-project/pull/214755

Claude assisted with this patch.

>From d4ce6a6138bc4af6cb85156ab8945493cb1228ef Mon Sep 17 00:00:00 2001
From: Robert Imschweiler <robert.imschweiler at amd.com>
Date: Fri, 7 Aug 2026 02:43:12 -0500
Subject: [PATCH] [offload] Thread allocation kind through async info

Claude assisted with this patch.
---
 offload/include/Shared/APITypes.h             |  7 ++-
 .../common/include/PluginInterface.h          |  4 +-
 .../common/src/PluginInterface.cpp            | 44 ++++++++++++++++---
 3 files changed, 44 insertions(+), 11 deletions(-)

diff --git a/offload/include/Shared/APITypes.h b/offload/include/Shared/APITypes.h
index 47d8c49bf7ef2..67edc7c9f60b7 100644
--- a/offload/include/Shared/APITypes.h
+++ b/offload/include/Shared/APITypes.h
@@ -23,6 +23,9 @@
 #include <cstddef>
 #include <cstdint>
 #include <mutex>
+#include <utility>
+
+enum TargetAllocTy : int32_t;
 
 extern "C" {
 
@@ -75,8 +78,8 @@ struct __tgt_async_info {
   void *Queue = nullptr;
 
   /// A collection of allocations that are associated with this stream and that
-  /// should be freed after finalization.
-  llvm::SmallVector<void *, 2> AssociatedAllocations;
+  /// should be freed after finalization. Also store the type of the allocation.
+  llvm::SmallVector<std::pair<void *, TargetAllocTy>, 2> AssociatedAllocations;
 
   /// Mutex to guard access to AssociatedAllocations and the Queue.
   std::mutex Mutex;
diff --git a/offload/plugins-nextgen/common/include/PluginInterface.h b/offload/plugins-nextgen/common/include/PluginInterface.h
index 50be67886c527..0b6a2223a75ce 100644
--- a/offload/plugins-nextgen/common/include/PluginInterface.h
+++ b/offload/plugins-nextgen/common/include/PluginInterface.h
@@ -168,9 +168,9 @@ struct AsyncInfoWrapperTy {
 
   /// Register \p Ptr as an associated allocation that is freed after
   /// finalization.
-  void freeAllocationAfterSynchronization(void *Ptr) {
+  void freeAllocationAfterSynchronization(void *Ptr, TargetAllocTy Kind) {
     std::lock_guard<std::mutex> AllocationGuard(AsyncInfoPtr->Mutex);
-    AsyncInfoPtr->AssociatedAllocations.push_back(Ptr);
+    AsyncInfoPtr->AssociatedAllocations.push_back({Ptr, Kind});
   }
 
 private:
diff --git a/offload/plugins-nextgen/common/src/PluginInterface.cpp b/offload/plugins-nextgen/common/src/PluginInterface.cpp
index 389d2ffbf4395..f4dcff3879ccd 100644
--- a/offload/plugins-nextgen/common/src/PluginInterface.cpp
+++ b/offload/plugins-nextgen/common/src/PluginInterface.cpp
@@ -137,7 +137,8 @@ GenericKernelTy::getKernelLaunchEnvironment(
     return AllocOrErr.takeError();
 
   // Remember to free the memory later.
-  AsyncInfoWrapper.freeAllocationAfterSynchronization(*AllocOrErr);
+  AsyncInfoWrapper.freeAllocationAfterSynchronization(
+      *AllocOrErr, TargetAllocTy::TARGET_ALLOC_DEVICE);
 
   /// Use the KLE in the __tgt_async_info to ensure a stable address for the
   /// async data transfer.
@@ -159,7 +160,8 @@ GenericKernelTy::getKernelLaunchEnvironment(
       return AllocOrErr.takeError();
     LocalKLE.ReductionBuffer = *AllocOrErr;
     // Remember to free the memory later.
-    AsyncInfoWrapper.freeAllocationAfterSynchronization(*AllocOrErr);
+    AsyncInfoWrapper.freeAllocationAfterSynchronization(
+        *AllocOrErr, TargetAllocTy::TARGET_ALLOC_DEVICE);
   }
 
   INFO(OMP_INFOTYPE_DATA_TRANSFER, GenericDevice.getDeviceId(),
@@ -289,7 +291,7 @@ Error GenericKernelTy::launch(GenericDeviceTy &GenericDevice, void **ArgPtrs,
   DynBlockMemConfTy &DynBlockMemConf = *DynBlockMemConfOrErr;
   if (DynBlockMemConf.FallbackPtr)
     AsyncInfoWrapper.freeAllocationAfterSynchronization(
-        DynBlockMemConf.FallbackPtr);
+        DynBlockMemConf.FallbackPtr, TargetAllocTy::TARGET_ALLOC_DEVICE);
 
   auto KernelLaunchEnvOrErr =
       getKernelLaunchEnvironment(GenericDevice, KernelArgs, DynBlockMemConf,
@@ -976,7 +978,7 @@ Error GenericDeviceTy::synchronize(__tgt_async_info *AsyncInfo,
     return Plugin::error(ErrorCode::INVALID_ARGUMENT,
                          "invalid async info queue");
 
-  SmallVector<void *> AllocsToDelete{};
+  SmallVector<std::pair<void *, TargetAllocTy>> AllocsToDelete{};
   {
     std::lock_guard<std::mutex> AllocationGuard{AsyncInfo->Mutex};
 
@@ -989,8 +991,8 @@ Error GenericDeviceTy::synchronize(__tgt_async_info *AsyncInfo,
     std::swap(AllocsToDelete, AsyncInfo->AssociatedAllocations);
   }
 
-  for (auto *Ptr : AllocsToDelete)
-    if (auto Err = dataDelete(Ptr, TargetAllocTy::TARGET_ALLOC_DEVICE))
+  for (auto [Ptr, Kind] : AllocsToDelete)
+    if (auto Err = dataDelete(Ptr, Kind))
       return Err;
 
   return Plugin::success();
@@ -1003,7 +1005,35 @@ Error GenericDeviceTy::queryAsync(__tgt_async_info *AsyncInfo,
     return Plugin::error(ErrorCode::INVALID_ARGUMENT,
                          "invalid async info queue");
 
-  return queryAsyncImpl(*AsyncInfo, ReleaseQueue, IsQueueWorkCompleted);
+  bool WorkCompleted = false;
+  SmallVector<std::pair<void *, TargetAllocTy>> AllocsToDelete{};
+
+  {
+    // Query and collect under the mutex, as synchronize does. Querying outside
+    // it would let an operation issued in between have its allocations freed
+    // here while it is still using them.
+    std::lock_guard<std::mutex> AllocationGuard{AsyncInfo->Mutex};
+    if (auto Err = queryAsyncImpl(*AsyncInfo, ReleaseQueue, &WorkCompleted)) {
+      if (IsQueueWorkCompleted)
+        *IsQueueWorkCompleted = WorkCompleted;
+      return Err;
+    }
+
+    // An async info belonging to a nowait task is never synchronized, so this
+    // is the only completion notification it ever gets. Without releasing its
+    // allocations here they are never freed at all.
+    if (WorkCompleted)
+      std::swap(AllocsToDelete, AsyncInfo->AssociatedAllocations);
+  }
+
+  for (auto [Ptr, Kind] : AllocsToDelete)
+    if (auto Err = dataDelete(Ptr, Kind))
+      return Err;
+
+  if (IsQueueWorkCompleted)
+    *IsQueueWorkCompleted = WorkCompleted;
+
+  return Plugin::success();
 }
 
 Error GenericDeviceTy::memoryVAMap(void **Addr, void *VAddr, size_t *RSize) {