| Issue |
154948
|
| Summary |
[MLIR] Race condition on DeadCodeAnalysis
|
| Labels |
mlir
|
| Assignees |
|
| Reporter |
amd-eochoalo
|
The title specifically mentions DeadCodeAnalysis, but I believe this may affect all DataFlowAnalysis when analyses are issued at the FuncOp level as opposed to the ModuleOp level.
The concrete issue raised by TSan started with [this patch](https://github.com/llvm/llvm-project/pull/150775). TSan found a race condition when `UnsignedWhenEquivalent` and `LowerAffine` are scheduled at the FuncOp level.
I am attaching the read and write traces from TSan.
```
WARNING: ThreadSanitizer: data race (pid=1005165)
Read of size 8 at 0x722800004028 by thread T4:
#0 mlir::iree_compiler::IREE::Util::FuncOp::getInherentAttr(mlir::MLIRContext*, mlir::iree_compiler::IREE::Util::detail::FuncOpGenericAdaptorBase::Properties const&, llvm::StringRef) /home/eochoalo/code/iree-build/compiler/src/iree/compiler/Dialect/Util/IR/UtilOps.cpp.inc (libIREECompiler.so+0xfc20346) (BuildId: 761b80a368cfa643)
#1 mlir::RegisteredOperationName::Model<mlir::iree_compiler::IREE::Util::FuncOp>::getInherentAttr(mlir::Operation*, llvm::StringRef) /home/eochoalo/code/iree/third_party/llvm-project/mlir/include/mlir/IR/OperationSupport.h:570:16 (libIREECompiler.so+0xfb8f4cd) (BuildId: 761b80a368cfa643)
#2 mlir::OperationName::getInherentAttr(mlir::Operation*, llvm::StringRef) const /home/eochoalo/code/iree/third_party/llvm-project/mlir/include/mlir/IR/OperationSupport.h:393:23 (libIREECompiler.so+0x7dd33c4) (BuildId: 761b80a368cfa643)
#3 mlir::Operation::getInherentAttr(llvm::StringRef) /home/eochoalo/code/iree/third_party/llvm-project/mlir/lib/IR/Operation.cpp:341:20 (libIREECompiler.so+0x7dd33c4)
#4 mlir::Operation::getAttr(mlir::StringAttr) /home/eochoalo/code/iree/third_party/llvm-project/mlir/include/mlir/IR/Operation.h:536:51 (libIREECompiler.so+0x7df9408) (BuildId: 761b80a368cfa643)
#5 mlir::StringAttr mlir::Operation::getAttrOfType<mlir::StringAttr>(mlir::StringAttr) /home/eochoalo/code/iree/third_party/llvm-project/mlir/include/mlir/IR/Operation.h:551:46 (libIREECompiler.so+0x7df9408)
#6 getNameIfSymbol(mlir::Operation*, mlir::StringAttr) /home/eochoalo/code/iree/third_party/llvm-project/mlir/lib/IR/SymbolTable.cpp:31:14 (libIREECompiler.so+0x7df9408)
#7 mlir::SymbolTable::SymbolTable(mlir::Operation*) /home/eochoalo/code/iree/third_party/llvm-project/mlir/lib/IR/SymbolTable.cpp:129:23 (libIREECompiler.so+0x7df9408)
#8 std::__detail::_MakeUniq<mlir::SymbolTable>::__single_object std::make_unique<mlir::SymbolTable, mlir::Operation*&>(mlir::Operation*&) /usr/bin/../lib/gcc/x86_64-linux-gnu/13/../../../../include/c++/13/bits/unique_ptr.h:1070:34 (libIREECompiler.so+0x7e0124d) (BuildId: 761b80a368cfa643)
#9 mlir::SymbolTableCollection::getSymbolTable(mlir::Operation*) /home/eochoalo/code/iree/third_party/llvm-project/mlir/lib/IR/SymbolTable.cpp:996:24 (libIREECompiler.so+0x7e0124d)
#10 mlir::SymbolTableCollection::lookupSymbolIn(mlir::Operation*, mlir::StringAttr) /home/eochoalo/code/iree/third_party/llvm-project/mlir/lib/IR/SymbolTable.cpp:954:10 (libIREECompiler.so+0x7e00ee6) (BuildId: 761b80a368cfa643)
#11 mlir::SymbolTableCollection::lookupSymbolIn(mlir::Operation*, mlir::SymbolRefAttr, llvm::SmallVectorImpl<mlir::Operation*>&)::$_0::operator()(mlir::Operation*, mlir::StringAttr) const /home/eochoalo/code/iree/third_party/llvm-project/mlir/lib/IR/SymbolTable.cpp:971:12 (libIREECompiler.so+0x7e087ad) (BuildId: 761b80a368cfa643)
#12 mlir::Operation* llvm::function_ref<mlir::Operation* (mlir::Operation*, mlir::StringAttr)>::callback_fn<mlir::SymbolTableCollection::lookupSymbolIn(mlir::Operation*, mlir::SymbolRefAttr, llvm::SmallVectorImpl<mlir::Operation*>&)::$_0>(long, mlir::Operation*, mlir::StringAttr) /home/eochoalo/code/iree/third_party/llvm-project/llvm/include/llvm/ADT/STLFunctionalExtras.h:46:12 (libIREECompiler.so+0x7e087ad)
#13 llvm::function_ref<mlir::Operation* (mlir::Operation*, mlir::StringAttr)>::operator()(mlir::Operation*, mlir::StringAttr) const /home/eochoalo/code/iree/third_party/llvm-project/llvm/include/llvm/ADT/STLFunctionalExtras.h:69:12 (libIREECompiler.so+0x7dfca9a) (BuildId: 761b80a368cfa643)
#14 lookupSymbolInImpl(mlir::Operation*, mlir::SymbolRefAttr, llvm::SmallVectorImpl<mlir::Operation*>&, llvm::function_ref<mlir::Operation* (mlir::Operation*, mlir::StringAttr)>) /home/eochoalo/code/iree/third_party/llvm-project/mlir/lib/IR/SymbolTable.cpp:416:19 (libIREECompiler.so+0x7dfca9a)
#15 mlir::SymbolTableCollection::lookupSymbolIn(mlir::Operation*, mlir::SymbolRefAttr, llvm::SmallVectorImpl<mlir::Operation*>&) /home/eochoalo/code/iree/third_party/llvm-project/mlir/lib/IR/SymbolTable.cpp:973:10 (libIREECompiler.so+0x7e010ea) (BuildId: 761b80a368cfa643)
#16 mlir::SymbolTableCollection::lookupSymbolIn(mlir::Operation*, mlir::SymbolRefAttr) /home/eochoalo/code/iree/third_party/llvm-project/mlir/lib/IR/SymbolTable.cpp:959:14 (libIREECompiler.so+0x7e0100e) (BuildId: 761b80a368cfa643)
#17 mlir::SymbolTableCollection::lookupNearestSymbolFrom(mlir::Operation*, mlir::SymbolRefAttr) /home/eochoalo/code/iree/third_party/llvm-project/mlir/lib/IR/SymbolTable.cpp:989:26 (libIREECompiler.so+0x7e011b2) (BuildId: 761b80a368cfa643)
#18 mlir::call_interface_impl::resolveCallable(mlir::CallOpInterface, mlir::SymbolTableCollection*) /home/eochoalo/code/iree/third_party/llvm-project/mlir/lib/Interfaces/CallInterfaces.cpp:196:25 (libIREECompiler.so+0x10530569) (BuildId: 761b80a368cfa643)
#19 mlir::detail::CallOpInterfaceTrait<mlir::iree_compiler::IREE::Util::CallOp>::resolveCallableInTable(mlir::SymbolTableCollection*) /home/eochoalo/code/iree-build/llvm-project/tools/mlir/include/mlir/Interfaces/CallInterfaces.h.inc:156:14 (libIREECompiler.so+0xfb885e2) (BuildId: 761b80a368cfa643) #20 mlir::detail::CallOpInterfaceInterfaceTraits::Model<mlir::iree_compiler::IREE::Util::CallOp>::resolveCallableInTable(mlir::detail::CallOpInterfaceInterfaceTraits::Concept const*, mlir::Operation*, mlir::SymbolTableCollection*) /home/eochoalo/code/iree-build/llvm-project/tools/mlir/include/mlir/Interfaces/CallInterfaces.h.inc:303:56 (libIREECompiler.so+0xfb885e2)
#21 mlir::CallOpInterface::resolveCallableInTable(mlir::SymbolTableCollection*) /home/eochoalo/code/iree-build/llvm-project/tools/mlir/include/mlir/Interfaces/CallInterfaces.cpp.inc:44:14 (libIREECompiler.so+0x10530797) (BuildId: 761b80a368cfa643)
#22 mlir::dataflow::DeadCodeAnalysis::visitCallOperation(mlir::CallOpInterface) /home/eochoalo/code/iree/third_party/llvm-project/mlir/lib/Analysis/DataFlow/DeadCodeAnalysis.cpp:362:32 (libIREECompiler.so+0x104ec31f) (BuildId: 761b80a368cfa643)
#23 mlir::dataflow::DeadCodeAnalysis::visit(mlir::ProgramPoint*) /home/eochoalo/code/iree/third_party/llvm-project/mlir/lib/Analysis/DataFlow/DeadCodeAnalysis.cpp:301:5 (libIREECompiler.so+0x104eb40a) (BuildId: 761b80a368cfa643) #24 mlir::DataFlowSolver::initializeAndRun(mlir::Operation*) /home/eochoalo/code/iree/third_party/llvm-project/mlir/lib/Analysis/DataFlowFramework.cpp:134:26 (libIREECompiler.so+0x104c4eb9) (BuildId: 761b80a368cfa643)
#25 (anonymous namespace)::ArithUnsignedWhenEquivalentPass::runOnOperation() /home/eochoalo/code/iree/third_party/llvm-project/mlir/lib/Dialect/Arith/Transforms/UnsignedWhenEquivalent.cpp:130:23 (libIREECompiler.so+0xe4e7503) (BuildId: 761b80a368cfa643)
```
```
Previous write of size 8 at 0x722800004028 by thread T2:
#0 __tsan_memcpy <null> (iree-compile+0x99d7f) (BuildId: 302c91be97368fb1)
#1 mlir::RegisteredOperationName::Model<mlir::iree_compiler::IREE::Util::FuncOp>::copyProperties(mlir::OpaqueProperties, mlir::OpaqueProperties) /home/eochoalo/code/iree/third_party/llvm-project/mlir/include/mlir/IR/OperationSupport.h:661:31 (libIREECompiler.so+0xfb8f7f5) (BuildId: 761b80a368cfa643)
#2 mlir::OperationName::copyOpProperties(mlir::OpaqueProperties, mlir::OpaqueProperties) const /home/eochoalo/code/iree/third_party/llvm-project/mlir/include/mlir/IR/OperationSupport.h:445:23 (libIREECompiler.so+0x7dd3829) (BuildId: 761b80a368cfa643)
#3 mlir::Operation::copyProperties(mlir::OpaqueProperties) /home/eochoalo/code/iree/third_party/llvm-project/mlir/lib/IR/Operation.cpp:366:8 (libIREECompiler.so+0x7dd3829)
#4 (anonymous namespace)::ModifyOperationRewrite::rollback() /home/eochoalo/code/iree/third_party/llvm-project/mlir/lib/Transforms/Utils/DialectConversion.cpp:712:11 (libIREECompiler.so+0xfd8eb00) (BuildId: 761b80a368cfa643)
#5 mlir::ConversionPatternRewriter::cancelOpModification(mlir::Operation*) /home/eochoalo/code/iree/third_party/llvm-project/mlir/lib/Transforms/Utils/DialectConversion.cpp:1954:10 (libIREECompiler.so+0xfd707ce)
...
#14 applyConversion(llvm::ArrayRef<mlir::Operation*>, mlir::ConversionTarget const&, mlir::FrozenRewritePatternSet const&, mlir::ConversionConfig, (anonymous namespace)::OpConversionMode) /home/eochoalo/code/iree/third_party/llvm-project/mlir/lib/Transforms/Utils/DialectConversion.cpp:3573:8 (libIREECompiler.so+0xfd7a13a)
#15 mlir::applyPartialConversion(llvm::ArrayRef<mlir::Operation*>, mlir::ConversionTarget const&, mlir::FrozenRewritePatternSet const&, mlir::ConversionConfig) /home/eochoalo/code/iree/third_party/llvm-project/mlir/lib/Transforms/Utils/DialectConversion.cpp:3589:10 (libIREECompiler.so+0xfd7a210) (BuildId: 761b80a368cfa643)
#16 mlir::applyPartialConversion(mlir::Operation*, mlir::ConversionTarget const&, mlir::FrozenRewritePatternSet const&, mlir::ConversionConfig) /home/eochoalo/code/iree/third_party/llvm-project/mlir/lib/Transforms/Utils/DialectConversion.cpp:3596:10 (libIREECompiler.so+0xfd7a210)
#17 (anonymous namespace)::LowerAffine::runOnOperation() /home/eochoalo/code/iree/third_party/llvm-project/mlir/lib/Conversion/AffineToStandard/AffineToStandard.cpp:564:16
```
I tried applying the following patch to avoid resolving the call, but the error moves to AbstractSparseForwardDataFlowAnalysis.
```diff
diff --git a/mlir/lib/Analysis/DataFlow/DeadCodeAnalysis.cpp b/mlir/lib/Analysis/DataFlow/DeadCodeAnalysis.cpp
index 10874fd0feb5..a04dd30482b7 100644
--- a/mlir/lib/Analysis/DataFlow/DeadCodeAnalysis.cpp
+++ b/mlir/lib/Analysis/DataFlow/DeadCodeAnalysis.cpp
@@ -20,6 +20,7 @@
#include "mlir/IR/ValueRange.h"
#include "mlir/Interfaces/CallInterfaces.h"
#include "mlir/Interfaces/ControlFlowInterfaces.h"
+#include "mlir/Interfaces/FunctionInterfaces.h"
#include "mlir/Support/LLVM.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Debug.h"
@@ -359,15 +360,28 @@ LogicalResult DeadCodeAnalysis::visit(ProgramPoint *point) {
void DeadCodeAnalysis::visitCallOperation(CallOpInterface call) {
LDBG() << "visitCallOperation: " << call.getOperation()->getName();
- Operation *callableOp = call.resolveCallableInTable(&symbolTable);
+ Operation *parent = call->getParentOfType<FunctionOpInterface>();
+ if (analysisScope == parent) {
+ return;
+ }
// A call to a externally-defined callable has unknown predecessors.
- const auto isExternalCallable = [this](Operation *op) {
+ const auto isExternalCallable = [this](CallOpInterface call) {
+ Operation *parent = call->getParentOfType<FunctionOpInterface>();
+ if (analysisScope == parent) {
+ return true;
+ }
+
+ Operation *callableOp = call.resolveCallableInTable(&symbolTable);
+
+ if (isa_and_nonnull<SymbolOpInterface>(callableOp)) {
+ return true;
+ }
// A callable outside the analysis scope is an external callable.
- if (!analysisScope->isAncestor(op))
+ if (!analysisScope->isAncestor(callableOp))
return true;
// Otherwise, check if the callable region is defined.
- if (auto callable = dyn_cast<CallableOpInterface>(op))
+ if (auto callable = dyn_cast<CallableOpInterface>(callableOp))
return !callable.getCallableRegion();
return false;
};
@@ -375,8 +389,8 @@ void DeadCodeAnalysis::visitCallOperation(CallOpInterface call) {
// TODO: Add support for non-symbol callables when necessary. If the
// callable has non-call uses we would mark as having reached pessimistic
// fixpoint, otherwise allow for propagating the return values out.
- if (isa_and_nonnull<SymbolOpInterface>(callableOp) &&
- !isExternalCallable(callableOp)) {
+ if (!isExternalCallable(call)) {
+ Operation *callableOp = call.resolveCallableInTable(&symbolTable);
// Add the live callsite.
auto *callsites =
getOrCreate<PredecessorState>(getProgramPointAfter(callableOp));
```
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