diff --git a/llvm/include/llvm/DWARFLinkerParallel/StringPool.h b/llvm/include/llvm/DWARFLinkerParallel/StringPool.h
--- a/llvm/include/llvm/DWARFLinkerParallel/StringPool.h
+++ b/llvm/include/llvm/DWARFLinkerParallel/StringPool.h
@@ -12,6 +12,7 @@
 #include "llvm/ADT/ConcurrentHashtable.h"
 #include "llvm/CodeGen/DwarfStringPoolEntry.h"
 #include "llvm/Support/Allocator.h"
+#include "llvm/Support/PerThreadBumpPtrAllocator.h"
 #include <string>
 #include <string_view>
 
@@ -22,28 +23,6 @@
 /// and a string body which is placed right after StringEntry.
 using StringEntry = StringMapEntry<DwarfStringPoolEntry *>;
 
-class StringAllocator : public AllocatorBase<StringAllocator> {
-public:
-  inline LLVM_ATTRIBUTE_RETURNS_NONNULL void *Allocate(size_t Size,
-                                                       size_t Alignment) {
-#if LLVM_ENABLE_THREADS
-    std::lock_guard<std::mutex> Guard(AllocatorMutex);
-#endif
-
-    return Allocator.Allocate(Size, Align(Alignment));
-  }
-
-  // Pull in base class overloads.
-  using AllocatorBase<StringAllocator>::Allocate;
-
-private:
-#if LLVM_ENABLE_THREADS
-  std::mutex AllocatorMutex;
-#endif
-
-  BumpPtrAllocator Allocator;
-};
-
 class StringPoolEntryInfo {
 public:
   /// \returns Hash value for the specified \p Key.
@@ -62,28 +41,31 @@
   }
 
   /// \returns newly created object of KeyDataTy type.
-  static inline StringEntry *create(const StringRef &Key,
-                                    StringAllocator &Allocator) {
+  static inline StringEntry *
+  create(const StringRef &Key, parallel::PerThreadBumpPtrAllocator &Allocator) {
     return StringEntry::create(Key, Allocator);
   }
 };
 
 class StringPool
-    : public ConcurrentHashTableByPtr<StringRef, StringEntry, StringAllocator,
+    : public ConcurrentHashTableByPtr<StringRef, StringEntry,
+                                      parallel::PerThreadBumpPtrAllocator,
                                       StringPoolEntryInfo> {
 public:
   StringPool()
-      : ConcurrentHashTableByPtr<StringRef, StringEntry, StringAllocator,
+      : ConcurrentHashTableByPtr<StringRef, StringEntry,
+                                 parallel::PerThreadBumpPtrAllocator,
                                  StringPoolEntryInfo>(Allocator) {}
 
   StringPool(size_t InitialSize)
-      : ConcurrentHashTableByPtr<StringRef, StringEntry, StringAllocator,
+      : ConcurrentHashTableByPtr<StringRef, StringEntry,
+                                 parallel::PerThreadBumpPtrAllocator,
                                  StringPoolEntryInfo>(Allocator, InitialSize) {}
 
-  StringAllocator &getAllocatorRef() { return Allocator; }
+  parallel::PerThreadBumpPtrAllocator &getAllocatorRef() { return Allocator; }
 
 private:
-  StringAllocator Allocator;
+  parallel::PerThreadBumpPtrAllocator Allocator;
 };
 
 } // end of namespace dwarflinker_parallel
diff --git a/llvm/include/llvm/Support/Parallel.h b/llvm/include/llvm/Support/Parallel.h
--- a/llvm/include/llvm/Support/Parallel.h
+++ b/llvm/include/llvm/Support/Parallel.h
@@ -48,8 +48,11 @@
 
 inline unsigned getThreadIndex() { GET_THREAD_INDEX_IMPL; }
 #endif
+
+size_t getNumThreads();
 #else
 inline unsigned getThreadIndex() { return 0; }
+inline size_t getNumThreads() { return 1; }
 #endif
 
 namespace detail {
diff --git a/llvm/include/llvm/Support/PerThreadBumpPtrAllocator.h b/llvm/include/llvm/Support/PerThreadBumpPtrAllocator.h
new file mode 100644
--- /dev/null
+++ b/llvm/include/llvm/Support/PerThreadBumpPtrAllocator.h
@@ -0,0 +1,120 @@
+//===- PerThreadBumpPtrAllocator.h ------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_PERTHREADBUMPPTRALLOCATOR_H
+#define LLVM_SUPPORT_PERTHREADBUMPPTRALLOCATOR_H
+
+#include "llvm/Support/Allocator.h"
+#include "llvm/Support/Parallel.h"
+
+namespace llvm {
+namespace parallel {
+
+/// PerThreadAllocator is used in conjunction with ThreadPoolExecutor to allow
+/// per-thread allocations. It wraps a possibly thread-unsafe allocator,
+/// e.g. BumpPtrAllocator. PerThreadAllocator must be used with only main thread
+/// or threads created by ThreadPoolExecutor, as it utilizes getThreadIndex,
+/// which is set by ThreadPoolExecutor. To work properly, ThreadPoolExecutor
+/// should be initialized before PerThreadAllocator is created.
+/// TODO: The same approach might be implemented for ThreadPool.
+
+template <typename AllocatorTy>
+class PerThreadAllocator
+    : public AllocatorBase<PerThreadAllocator<AllocatorTy>> {
+public:
+  PerThreadAllocator()
+      : NumOfAllocators(parallel::getNumThreads()),
+        Allocators(std::make_unique<AllocatorTy[]>(NumOfAllocators)) {}
+
+  /// \defgroup Methods which could be called asynchronously:
+  ///
+  /// @{
+
+  using AllocatorBase<PerThreadAllocator<AllocatorTy>>::Allocate;
+
+  using AllocatorBase<PerThreadAllocator<AllocatorTy>>::Deallocate;
+
+  /// Allocate \a Size bytes of \a Alignment aligned memory.
+  void *Allocate(size_t Size, size_t Alignment) {
+    assert(getThreadIndex() < NumOfAllocators);
+    return Allocators[getThreadIndex()].Allocate(Size, Alignment);
+  }
+
+  /// Deallocate \a Ptr to \a Size bytes of memory allocated by this
+  /// allocator.
+  void Deallocate(const void *Ptr, size_t Size, size_t Alignment) {
+    assert(getThreadIndex() < NumOfAllocators);
+    return Allocators[getThreadIndex()].Deallocate(Ptr, Size, Alignment);
+  }
+
+  /// Return allocator corresponding to the current thread.
+  AllocatorTy &getThreadLocalAllocator() {
+    assert(getThreadIndex() < NumOfAllocators);
+    return Allocators[getThreadIndex()];
+  }
+
+  // Return number of used allocators.
+  size_t getNumberOfAllocators() const { return NumOfAllocators; }
+  /// @}
+
+  /// \defgroup Methods which could not be called asynchronously:
+  ///
+  /// @{
+
+  /// Reset state of allocators.
+  void Reset() {
+    for (size_t Idx = 0; Idx < getNumberOfAllocators(); Idx++)
+      Allocators[Idx].Reset();
+  }
+
+  /// Return total memory size used by all allocators.
+  size_t getTotalMemory() const {
+    size_t TotalMemory = 0;
+
+    for (size_t Idx = 0; Idx < getNumberOfAllocators(); Idx++)
+      TotalMemory += Allocators[Idx].getTotalMemory();
+
+    return TotalMemory;
+  }
+
+  /// Return allocated size by all allocators.
+  size_t getBytesAllocated() const {
+    size_t BytesAllocated = 0;
+
+    for (size_t Idx = 0; Idx < getNumberOfAllocators(); Idx++)
+      BytesAllocated += Allocators[Idx].getBytesAllocated();
+
+    return BytesAllocated;
+  }
+
+  /// Set red zone for all allocators.
+  void setRedZoneSize(size_t NewSize) {
+    for (size_t Idx = 0; Idx < getNumberOfAllocators(); Idx++)
+      Allocators[Idx].setRedZoneSize(NewSize);
+  }
+
+  /// Print statistic for each allocator.
+  void PrintStats() const {
+    for (size_t Idx = 0; Idx < getNumberOfAllocators(); Idx++) {
+      errs() << "\n Allocator " << Idx << "\n";
+      Allocators[Idx].PrintStats();
+    }
+  }
+  /// @}
+
+protected:
+  size_t NumOfAllocators;
+  std::unique_ptr<AllocatorTy[]> Allocators;
+};
+
+using PerThreadBumpPtrAllocator = PerThreadAllocator<BumpPtrAllocator>;
+
+} // end namespace parallel
+} // end namespace llvm
+
+#endif // LLVM_SUPPORT_PERTHREADBUMPPTRALLOCATOR_H
diff --git a/llvm/lib/Support/Parallel.cpp b/llvm/lib/Support/Parallel.cpp
--- a/llvm/lib/Support/Parallel.cpp
+++ b/llvm/lib/Support/Parallel.cpp
@@ -40,6 +40,7 @@
 public:
   virtual ~Executor() = default;
   virtual void add(std::function<void()> func, bool Sequential = false) = 0;
+  virtual size_t getThreadsNum() const = 0;
 
   static Executor *getDefaultExecutor();
 };
@@ -49,7 +50,7 @@
 class ThreadPoolExecutor : public Executor {
 public:
   explicit ThreadPoolExecutor(ThreadPoolStrategy S = hardware_concurrency()) {
-    unsigned ThreadCount = S.compute_thread_count();
+    ThreadCount = S.compute_thread_count();
     // Spawn all but one of the threads in another thread as spawning threads
     // can take a while.
     Threads.reserve(ThreadCount);
@@ -58,7 +59,7 @@
     // Use operator[] before creating the thread to avoid data race in .size()
     // in “safe libc++” mode.
     auto &Thread0 = Threads[0];
-    Thread0 = std::thread([this, ThreadCount, S] {
+    Thread0 = std::thread([this, S] {
       for (unsigned I = 1; I < ThreadCount; ++I) {
         Threads.emplace_back([=] { work(S, I); });
         if (Stop)
@@ -108,6 +109,8 @@
     Cond.notify_one();
   }
 
+  size_t getThreadsNum() const override { return ThreadCount; }
+
 private:
   bool hasSequentialTasks() const {
     return !WorkQueueSequential.empty() && !SequentialQueueIsLocked;
@@ -149,6 +152,7 @@
   std::condition_variable Cond;
   std::promise<void> ThreadsCreated;
   std::vector<std::thread> Threads;
+  unsigned ThreadCount;
 };
 
 Executor *Executor::getDefaultExecutor() {
@@ -178,6 +182,10 @@
 }
 } // namespace
 } // namespace detail
+
+size_t getNumThreads() {
+  return detail::Executor::getDefaultExecutor()->getThreadsNum();
+}
 #endif
 
 // Latch::sync() called by the dtor may cause one thread to block. If is a dead
diff --git a/llvm/unittests/ADT/ConcurrentHashtableTest.cpp b/llvm/unittests/ADT/ConcurrentHashtableTest.cpp
--- a/llvm/unittests/ADT/ConcurrentHashtableTest.cpp
+++ b/llvm/unittests/ADT/ConcurrentHashtableTest.cpp
@@ -10,11 +10,13 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/FormatVariadic.h"
 #include "llvm/Support/Parallel.h"
+#include "llvm/Support/PerThreadBumpPtrAllocator.h"
 #include "gtest/gtest.h"
 #include <limits>
 #include <random>
 #include <vector>
 using namespace llvm;
+using namespace parallel;
 
 namespace {
 class String {
@@ -36,186 +38,195 @@
   std::array<char, 0x20> ExtraData;
 };
 
-class SimpleAllocator : public AllocatorBase<SimpleAllocator> {
-public:
-  inline LLVM_ATTRIBUTE_RETURNS_NONNULL void *Allocate(size_t Size,
-                                                       size_t Alignment) {
-#if LLVM_ENABLE_THREADS
-    std::lock_guard<std::mutex> Guard(AllocatorMutex);
-#endif
-
-    return Allocator.Allocate(Size, Align(Alignment));
-  }
-  inline size_t getBytesAllocated() {
-#if LLVM_ENABLE_THREADS
-    std::lock_guard<std::mutex> Guard(AllocatorMutex);
-#endif
-
-    return Allocator.getBytesAllocated();
-  }
-
-  // Pull in base class overloads.
-  using AllocatorBase<SimpleAllocator>::Allocate;
-
-protected:
-#if LLVM_ENABLE_THREADS
-  std::mutex AllocatorMutex;
-#endif
-  BumpPtrAllocator Allocator;
-} Allocator;
-
 TEST(ConcurrentHashTableTest, AddStringEntries) {
-  ConcurrentHashTableByPtr<
-      std::string, String, SimpleAllocator,
-      ConcurrentHashTableInfoByPtr<std::string, String, SimpleAllocator>>
+  PerThreadBumpPtrAllocator Allocator;
+  ConcurrentHashTableByPtr<std::string, String, PerThreadBumpPtrAllocator,
+                           ConcurrentHashTableInfoByPtr<
+                               std::string, String, PerThreadBumpPtrAllocator>>
       HashTable(Allocator, 10);
 
-  size_t AllocatedBytesAtStart = Allocator.getBytesAllocated();
-  std::pair<String *, bool> res1 = HashTable.insert("1");
-  // Check entry is inserted.
-  EXPECT_TRUE(res1.first->getKey() == "1");
-  EXPECT_TRUE(res1.second);
-
-  std::pair<String *, bool> res2 = HashTable.insert("2");
-  // Check old entry is still valid.
-  EXPECT_TRUE(res1.first->getKey() == "1");
-  // Check new entry is inserted.
-  EXPECT_TRUE(res2.first->getKey() == "2");
-  EXPECT_TRUE(res2.second);
-  // Check new and old entries use different memory.
-  EXPECT_TRUE(res1.first != res2.first);
-
-  std::pair<String *, bool> res3 = HashTable.insert("3");
-  // Check one more entry is inserted.
-  EXPECT_TRUE(res3.first->getKey() == "3");
-  EXPECT_TRUE(res3.second);
-
-  std::pair<String *, bool> res4 = HashTable.insert("1");
-  // Check duplicated entry is inserted.
-  EXPECT_TRUE(res4.first->getKey() == "1");
-  EXPECT_FALSE(res4.second);
-  // Check duplicated entry uses the same memory.
-  EXPECT_TRUE(res1.first == res4.first);
-
-  // Check first entry is still valid.
-  EXPECT_TRUE(res1.first->getKey() == "1");
-
-  // Check data was allocated by allocator.
-  EXPECT_TRUE(Allocator.getBytesAllocated() > AllocatedBytesAtStart);
+  // PerThreadBumpPtrAllocator should be accessed from threads created by
+  // ThreadPoolExecutor. Use TaskGroup to run on ThreadPoolExecutor threads.
+  parallel::TaskGroup tg;
 
-  // Check statistic.
-  std::string StatisticString;
-  raw_string_ostream StatisticStream(StatisticString);
-  HashTable.printStatistic(StatisticStream);
+  tg.spawn([&]() {
+    size_t AllocatedBytesAtStart = Allocator.getBytesAllocated();
+    std::pair<String *, bool> res1 = HashTable.insert("1");
+    // Check entry is inserted.
+    EXPECT_TRUE(res1.first->getKey() == "1");
+    EXPECT_TRUE(res1.second);
+
+    std::pair<String *, bool> res2 = HashTable.insert("2");
+    // Check old entry is still valid.
+    EXPECT_TRUE(res1.first->getKey() == "1");
+    // Check new entry is inserted.
+    EXPECT_TRUE(res2.first->getKey() == "2");
+    EXPECT_TRUE(res2.second);
+    // Check new and old entries use different memory.
+    EXPECT_TRUE(res1.first != res2.first);
+
+    std::pair<String *, bool> res3 = HashTable.insert("3");
+    // Check one more entry is inserted.
+    EXPECT_TRUE(res3.first->getKey() == "3");
+    EXPECT_TRUE(res3.second);
+
+    std::pair<String *, bool> res4 = HashTable.insert("1");
+    // Check duplicated entry is inserted.
+    EXPECT_TRUE(res4.first->getKey() == "1");
+    EXPECT_FALSE(res4.second);
+    // Check duplicated entry uses the same memory.
+    EXPECT_TRUE(res1.first == res4.first);
+
+    // Check first entry is still valid.
+    EXPECT_TRUE(res1.first->getKey() == "1");
+
+    // Check data was allocated by allocator.
+    EXPECT_TRUE(Allocator.getBytesAllocated() > AllocatedBytesAtStart);
 
-  EXPECT_TRUE(StatisticString.find("Overall number of entries = 3\n") !=
-              std::string::npos);
+    // Check statistic.
+    std::string StatisticString;
+    raw_string_ostream StatisticStream(StatisticString);
+    HashTable.printStatistic(StatisticStream);
+
+    EXPECT_TRUE(StatisticString.find("Overall number of entries = 3\n") !=
+                std::string::npos);
+  });
 }
 
 TEST(ConcurrentHashTableTest, AddStringMultiplueEntries) {
+  PerThreadBumpPtrAllocator Allocator;
   const size_t NumElements = 10000;
-  ConcurrentHashTableByPtr<
-      std::string, String, SimpleAllocator,
-      ConcurrentHashTableInfoByPtr<std::string, String, SimpleAllocator>>
+  ConcurrentHashTableByPtr<std::string, String, PerThreadBumpPtrAllocator,
+                           ConcurrentHashTableInfoByPtr<
+                               std::string, String, PerThreadBumpPtrAllocator>>
       HashTable(Allocator);
 
-  // Check insertion.
-  for (size_t I = 0; I < NumElements; I++) {
-    size_t AllocatedBytesAtStart = Allocator.getBytesAllocated();
-    std::string StringForElement = formatv("{0}", I);
-    std::pair<String *, bool> Entry = HashTable.insert(StringForElement);
-    EXPECT_TRUE(Entry.second);
-    EXPECT_TRUE(Entry.first->getKey() == StringForElement);
-    EXPECT_TRUE(Allocator.getBytesAllocated() > AllocatedBytesAtStart);
-  }
-
-  std::string StatisticString;
-  raw_string_ostream StatisticStream(StatisticString);
-  HashTable.printStatistic(StatisticStream);
-
-  // Verifying that the table contains exactly the number of elements we
-  // inserted.
-  EXPECT_TRUE(StatisticString.find("Overall number of entries = 10000\n") !=
-              std::string::npos);
-
-  // Check insertion of duplicates.
-  for (size_t I = 0; I < NumElements; I++) {
-    size_t AllocatedBytesAtStart = Allocator.getBytesAllocated();
-    std::string StringForElement = formatv("{0}", I);
-    std::pair<String *, bool> Entry = HashTable.insert(StringForElement);
-    EXPECT_FALSE(Entry.second);
-    EXPECT_TRUE(Entry.first->getKey() == StringForElement);
-    // Check no additional bytes were allocated for duplicate.
-    EXPECT_TRUE(Allocator.getBytesAllocated() == AllocatedBytesAtStart);
-  }
-
-  // Check statistic.
-  // Verifying that the table contains exactly the number of elements we
-  // inserted.
-  EXPECT_TRUE(StatisticString.find("Overall number of entries = 10000\n") !=
-              std::string::npos);
+  // PerThreadBumpPtrAllocator should be accessed from threads created by
+  // ThreadPoolExecutor. Use TaskGroup to run on ThreadPoolExecutor threads.
+  parallel::TaskGroup tg;
+
+  tg.spawn([&]() {
+    // Check insertion.
+    for (size_t I = 0; I < NumElements; I++) {
+      BumpPtrAllocator &ThreadLocalAllocator =
+          Allocator.getThreadLocalAllocator();
+      size_t AllocatedBytesAtStart = ThreadLocalAllocator.getBytesAllocated();
+      std::string StringForElement = formatv("{0}", I);
+      std::pair<String *, bool> Entry = HashTable.insert(StringForElement);
+      EXPECT_TRUE(Entry.second);
+      EXPECT_TRUE(Entry.first->getKey() == StringForElement);
+      EXPECT_TRUE(ThreadLocalAllocator.getBytesAllocated() >
+                  AllocatedBytesAtStart);
+    }
+
+    std::string StatisticString;
+    raw_string_ostream StatisticStream(StatisticString);
+    HashTable.printStatistic(StatisticStream);
+
+    // Verifying that the table contains exactly the number of elements we
+    // inserted.
+    EXPECT_TRUE(StatisticString.find("Overall number of entries = 10000\n") !=
+                std::string::npos);
+
+    // Check insertion of duplicates.
+    for (size_t I = 0; I < NumElements; I++) {
+      BumpPtrAllocator &ThreadLocalAllocator =
+          Allocator.getThreadLocalAllocator();
+      size_t AllocatedBytesAtStart = ThreadLocalAllocator.getBytesAllocated();
+      std::string StringForElement = formatv("{0}", I);
+      std::pair<String *, bool> Entry = HashTable.insert(StringForElement);
+      EXPECT_FALSE(Entry.second);
+      EXPECT_TRUE(Entry.first->getKey() == StringForElement);
+      // Check no additional bytes were allocated for duplicate.
+      EXPECT_TRUE(ThreadLocalAllocator.getBytesAllocated() ==
+                  AllocatedBytesAtStart);
+    }
+
+    // Check statistic.
+    // Verifying that the table contains exactly the number of elements we
+    // inserted.
+    EXPECT_TRUE(StatisticString.find("Overall number of entries = 10000\n") !=
+                std::string::npos);
+  });
 }
 
 TEST(ConcurrentHashTableTest, AddStringMultiplueEntriesWithResize) {
+  PerThreadBumpPtrAllocator Allocator;
   // Number of elements exceeds original size, thus hashtable should be resized.
   const size_t NumElements = 20000;
-  ConcurrentHashTableByPtr<
-      std::string, String, SimpleAllocator,
-      ConcurrentHashTableInfoByPtr<std::string, String, SimpleAllocator>>
+  ConcurrentHashTableByPtr<std::string, String, PerThreadBumpPtrAllocator,
+                           ConcurrentHashTableInfoByPtr<
+                               std::string, String, PerThreadBumpPtrAllocator>>
       HashTable(Allocator, 100);
 
-  // Check insertion.
-  for (size_t I = 0; I < NumElements; I++) {
-    size_t AllocatedBytesAtStart = Allocator.getBytesAllocated();
-    std::string StringForElement = formatv("{0} {1}", I, I + 100);
-    std::pair<String *, bool> Entry = HashTable.insert(StringForElement);
-    EXPECT_TRUE(Entry.second);
-    EXPECT_TRUE(Entry.first->getKey() == StringForElement);
-    EXPECT_TRUE(Allocator.getBytesAllocated() > AllocatedBytesAtStart);
-  }
-
-  std::string StatisticString;
-  raw_string_ostream StatisticStream(StatisticString);
-  HashTable.printStatistic(StatisticStream);
-
-  // Verifying that the table contains exactly the number of elements we
-  // inserted.
-  EXPECT_TRUE(StatisticString.find("Overall number of entries = 20000\n") !=
-              std::string::npos);
-
-  // Check insertion of duplicates.
-  for (size_t I = 0; I < NumElements; I++) {
-    size_t AllocatedBytesAtStart = Allocator.getBytesAllocated();
-    std::string StringForElement = formatv("{0} {1}", I, I + 100);
-    std::pair<String *, bool> Entry = HashTable.insert(StringForElement);
-    EXPECT_FALSE(Entry.second);
-    EXPECT_TRUE(Entry.first->getKey() == StringForElement);
-    // Check no additional bytes were allocated for duplicate.
-    EXPECT_TRUE(Allocator.getBytesAllocated() == AllocatedBytesAtStart);
-  }
-
-  // Check statistic.
-  // Verifying that the table contains exactly the number of elements we
-  // inserted.
-  EXPECT_TRUE(StatisticString.find("Overall number of entries = 20000\n") !=
-              std::string::npos);
+  // PerThreadBumpPtrAllocator should be accessed from threads created by
+  // ThreadPoolExecutor. Use TaskGroup to run on ThreadPoolExecutor threads.
+  parallel::TaskGroup tg;
+
+  tg.spawn([&]() {
+    // Check insertion.
+    for (size_t I = 0; I < NumElements; I++) {
+      BumpPtrAllocator &ThreadLocalAllocator =
+          Allocator.getThreadLocalAllocator();
+      size_t AllocatedBytesAtStart = ThreadLocalAllocator.getBytesAllocated();
+      std::string StringForElement = formatv("{0} {1}", I, I + 100);
+      std::pair<String *, bool> Entry = HashTable.insert(StringForElement);
+      EXPECT_TRUE(Entry.second);
+      EXPECT_TRUE(Entry.first->getKey() == StringForElement);
+      EXPECT_TRUE(ThreadLocalAllocator.getBytesAllocated() >
+                  AllocatedBytesAtStart);
+    }
+
+    std::string StatisticString;
+    raw_string_ostream StatisticStream(StatisticString);
+    HashTable.printStatistic(StatisticStream);
+
+    // Verifying that the table contains exactly the number of elements we
+    // inserted.
+    EXPECT_TRUE(StatisticString.find("Overall number of entries = 20000\n") !=
+                std::string::npos);
+
+    // Check insertion of duplicates.
+    for (size_t I = 0; I < NumElements; I++) {
+      BumpPtrAllocator &ThreadLocalAllocator =
+          Allocator.getThreadLocalAllocator();
+      size_t AllocatedBytesAtStart = ThreadLocalAllocator.getBytesAllocated();
+      std::string StringForElement = formatv("{0} {1}", I, I + 100);
+      std::pair<String *, bool> Entry = HashTable.insert(StringForElement);
+      EXPECT_FALSE(Entry.second);
+      EXPECT_TRUE(Entry.first->getKey() == StringForElement);
+      // Check no additional bytes were allocated for duplicate.
+      EXPECT_TRUE(ThreadLocalAllocator.getBytesAllocated() ==
+                  AllocatedBytesAtStart);
+    }
+
+    // Check statistic.
+    // Verifying that the table contains exactly the number of elements we
+    // inserted.
+    EXPECT_TRUE(StatisticString.find("Overall number of entries = 20000\n") !=
+                std::string::npos);
+  });
 }
 
 TEST(ConcurrentHashTableTest, AddStringEntriesParallel) {
+  PerThreadBumpPtrAllocator Allocator;
   const size_t NumElements = 10000;
-  ConcurrentHashTableByPtr<
-      std::string, String, SimpleAllocator,
-      ConcurrentHashTableInfoByPtr<std::string, String, SimpleAllocator>>
+  ConcurrentHashTableByPtr<std::string, String, PerThreadBumpPtrAllocator,
+                           ConcurrentHashTableInfoByPtr<
+                               std::string, String, PerThreadBumpPtrAllocator>>
       HashTable(Allocator);
 
   // Check parallel insertion.
   parallelFor(0, NumElements, [&](size_t I) {
-    size_t AllocatedBytesAtStart = Allocator.getBytesAllocated();
+    BumpPtrAllocator &ThreadLocalAllocator =
+        Allocator.getThreadLocalAllocator();
+    size_t AllocatedBytesAtStart = ThreadLocalAllocator.getBytesAllocated();
     std::string StringForElement = formatv("{0}", I);
     std::pair<String *, bool> Entry = HashTable.insert(StringForElement);
     EXPECT_TRUE(Entry.second);
     EXPECT_TRUE(Entry.first->getKey() == StringForElement);
-    EXPECT_TRUE(Allocator.getBytesAllocated() > AllocatedBytesAtStart);
+    EXPECT_TRUE(ThreadLocalAllocator.getBytesAllocated() >
+                AllocatedBytesAtStart);
   });
 
   std::string StatisticString;
@@ -229,13 +240,16 @@
 
   // Check parallel insertion of duplicates.
   parallelFor(0, NumElements, [&](size_t I) {
-    size_t AllocatedBytesAtStart = Allocator.getBytesAllocated();
+    BumpPtrAllocator &ThreadLocalAllocator =
+        Allocator.getThreadLocalAllocator();
+    size_t AllocatedBytesAtStart = ThreadLocalAllocator.getBytesAllocated();
     std::string StringForElement = formatv("{0}", I);
     std::pair<String *, bool> Entry = HashTable.insert(StringForElement);
     EXPECT_FALSE(Entry.second);
     EXPECT_TRUE(Entry.first->getKey() == StringForElement);
     // Check no additional bytes were allocated for duplicate.
-    EXPECT_TRUE(Allocator.getBytesAllocated() == AllocatedBytesAtStart);
+    EXPECT_TRUE(ThreadLocalAllocator.getBytesAllocated() ==
+                AllocatedBytesAtStart);
   });
 
   // Check statistic.
@@ -246,20 +260,24 @@
 }
 
 TEST(ConcurrentHashTableTest, AddStringEntriesParallelWithResize) {
+  PerThreadBumpPtrAllocator Allocator;
   const size_t NumElements = 20000;
-  ConcurrentHashTableByPtr<
-      std::string, String, SimpleAllocator,
-      ConcurrentHashTableInfoByPtr<std::string, String, SimpleAllocator>>
+  ConcurrentHashTableByPtr<std::string, String, PerThreadBumpPtrAllocator,
+                           ConcurrentHashTableInfoByPtr<
+                               std::string, String, PerThreadBumpPtrAllocator>>
       HashTable(Allocator, 100);
 
   // Check parallel insertion.
   parallelFor(0, NumElements, [&](size_t I) {
-    size_t AllocatedBytesAtStart = Allocator.getBytesAllocated();
+    BumpPtrAllocator &ThreadLocalAllocator =
+        Allocator.getThreadLocalAllocator();
+    size_t AllocatedBytesAtStart = ThreadLocalAllocator.getBytesAllocated();
     std::string StringForElement = formatv("{0}", I);
     std::pair<String *, bool> Entry = HashTable.insert(StringForElement);
     EXPECT_TRUE(Entry.second);
     EXPECT_TRUE(Entry.first->getKey() == StringForElement);
-    EXPECT_TRUE(Allocator.getBytesAllocated() > AllocatedBytesAtStart);
+    EXPECT_TRUE(ThreadLocalAllocator.getBytesAllocated() >
+                AllocatedBytesAtStart);
   });
 
   std::string StatisticString;
@@ -273,13 +291,16 @@
 
   // Check parallel insertion of duplicates.
   parallelFor(0, NumElements, [&](size_t I) {
-    size_t AllocatedBytesAtStart = Allocator.getBytesAllocated();
+    BumpPtrAllocator &ThreadLocalAllocator =
+        Allocator.getThreadLocalAllocator();
+    size_t AllocatedBytesAtStart = ThreadLocalAllocator.getBytesAllocated();
     std::string StringForElement = formatv("{0}", I);
     std::pair<String *, bool> Entry = HashTable.insert(StringForElement);
     EXPECT_FALSE(Entry.second);
     EXPECT_TRUE(Entry.first->getKey() == StringForElement);
     // Check no additional bytes were allocated for duplicate.
-    EXPECT_TRUE(Allocator.getBytesAllocated() == AllocatedBytesAtStart);
+    EXPECT_TRUE(ThreadLocalAllocator.getBytesAllocated() ==
+                AllocatedBytesAtStart);
   });
 
   // Check statistic.
diff --git a/llvm/unittests/DWARFLinkerParallel/StringPoolTest.cpp b/llvm/unittests/DWARFLinkerParallel/StringPoolTest.cpp
--- a/llvm/unittests/DWARFLinkerParallel/StringPoolTest.cpp
+++ b/llvm/unittests/DWARFLinkerParallel/StringPoolTest.cpp
@@ -19,24 +19,31 @@
 TEST(StringPoolTest, TestStringPool) {
   StringPool Strings;
 
-  std::pair<StringEntry *, bool> Entry = Strings.insert("test");
-  EXPECT_TRUE(Entry.second);
-  EXPECT_TRUE(Entry.first->getKey() == "test");
-  EXPECT_TRUE(Entry.first->second == nullptr);
-
-  StringEntry *EntryPtr = Entry.first;
-
-  Entry = Strings.insert("test");
-  EXPECT_FALSE(Entry.second);
-  EXPECT_TRUE(Entry.first->getKey() == "test");
-  EXPECT_TRUE(Entry.first->second == nullptr);
-  EXPECT_TRUE(EntryPtr == Entry.first);
-
-  Entry = Strings.insert("test2");
-  EXPECT_TRUE(Entry.second);
-  EXPECT_TRUE(Entry.first->getKey() == "test2");
-  EXPECT_TRUE(Entry.first->second == nullptr);
-  EXPECT_TRUE(EntryPtr != Entry.first);
+  // StringPool uses PerThreadBumpPtrAllocator which should be accessed from
+  // threads created by ThreadPoolExecutor. Use TaskGroup to run on
+  // ThreadPoolExecutor threads.
+  parallel::TaskGroup tg;
+
+  tg.spawn([&]() {
+    std::pair<StringEntry *, bool> Entry = Strings.insert("test");
+    EXPECT_TRUE(Entry.second);
+    EXPECT_TRUE(Entry.first->getKey() == "test");
+    EXPECT_TRUE(Entry.first->second == nullptr);
+
+    StringEntry *EntryPtr = Entry.first;
+
+    Entry = Strings.insert("test");
+    EXPECT_FALSE(Entry.second);
+    EXPECT_TRUE(Entry.first->getKey() == "test");
+    EXPECT_TRUE(Entry.first->second == nullptr);
+    EXPECT_TRUE(EntryPtr == Entry.first);
+
+    Entry = Strings.insert("test2");
+    EXPECT_TRUE(Entry.second);
+    EXPECT_TRUE(Entry.first->getKey() == "test2");
+    EXPECT_TRUE(Entry.first->second == nullptr);
+    EXPECT_TRUE(EntryPtr != Entry.first);
+  });
 }
 
 TEST(StringPoolTest, TestStringPoolParallel) {
diff --git a/llvm/unittests/DWARFLinkerParallel/StringTableTest.cpp b/llvm/unittests/DWARFLinkerParallel/StringTableTest.cpp
--- a/llvm/unittests/DWARFLinkerParallel/StringTableTest.cpp
+++ b/llvm/unittests/DWARFLinkerParallel/StringTableTest.cpp
@@ -29,41 +29,48 @@
   StringPool Strings;
   StringTable OutStrings(Strings, nullptr);
 
-  // Check string insertion.
-  StringEntry *FirstPtr = Strings.insert(InputStrings[0].Str).first;
-  StringEntry *SecondPtr = Strings.insert(InputStrings[1].Str).first;
-  StringEntry *ThirdPtr = Strings.insert(InputStrings[2].Str).first;
-
-  FirstPtr = OutStrings.add(FirstPtr);
-  SecondPtr = OutStrings.add(SecondPtr);
-  ThirdPtr = OutStrings.add(ThirdPtr);
-
-  // Check fields of inserted strings.
-  EXPECT_TRUE(FirstPtr->getKey() == InputStrings[0].Str);
-  EXPECT_TRUE(FirstPtr->getValue()->Offset == InputStrings[0].Offset);
-  EXPECT_TRUE(FirstPtr->getValue()->Index == InputStrings[0].Idx);
-
-  EXPECT_TRUE(SecondPtr->getKey() == InputStrings[1].Str);
-  EXPECT_TRUE(SecondPtr->getValue()->Offset == InputStrings[1].Offset);
-  EXPECT_TRUE(SecondPtr->getValue()->Index == InputStrings[1].Idx);
-
-  EXPECT_TRUE(ThirdPtr->getKey() == InputStrings[2].Str);
-  EXPECT_TRUE(ThirdPtr->getValue()->Offset == InputStrings[2].Offset);
-  EXPECT_TRUE(ThirdPtr->getValue()->Index == InputStrings[2].Idx);
-
-  // Check order enumerated strings.
-  uint64_t CurIdx = 0;
-  std::function<void(DwarfStringPoolEntryRef)> checkStr =
-      [&](DwarfStringPoolEntryRef Entry) {
-        EXPECT_TRUE(Entry.getEntry().isIndexed());
-        EXPECT_TRUE(Entry.getIndex() == CurIdx);
-        EXPECT_TRUE(Entry.getOffset() == InputStrings[CurIdx].Offset);
-        EXPECT_TRUE(Entry.getString() == InputStrings[CurIdx].Str);
-
-        CurIdx++;
-      };
-
-  OutStrings.forEach(checkStr);
+  // StringPool uses PerThreadBumpPtrAllocator which should be accessed from
+  // threads created by ThreadPoolExecutor. Use TaskGroup to run on
+  // ThreadPoolExecutor threads.
+  parallel::TaskGroup tg;
+
+  tg.spawn([&]() {
+    // Check string insertion.
+    StringEntry *FirstPtr = Strings.insert(InputStrings[0].Str).first;
+    StringEntry *SecondPtr = Strings.insert(InputStrings[1].Str).first;
+    StringEntry *ThirdPtr = Strings.insert(InputStrings[2].Str).first;
+
+    FirstPtr = OutStrings.add(FirstPtr);
+    SecondPtr = OutStrings.add(SecondPtr);
+    ThirdPtr = OutStrings.add(ThirdPtr);
+
+    // Check fields of inserted strings.
+    EXPECT_TRUE(FirstPtr->getKey() == InputStrings[0].Str);
+    EXPECT_TRUE(FirstPtr->getValue()->Offset == InputStrings[0].Offset);
+    EXPECT_TRUE(FirstPtr->getValue()->Index == InputStrings[0].Idx);
+
+    EXPECT_TRUE(SecondPtr->getKey() == InputStrings[1].Str);
+    EXPECT_TRUE(SecondPtr->getValue()->Offset == InputStrings[1].Offset);
+    EXPECT_TRUE(SecondPtr->getValue()->Index == InputStrings[1].Idx);
+
+    EXPECT_TRUE(ThirdPtr->getKey() == InputStrings[2].Str);
+    EXPECT_TRUE(ThirdPtr->getValue()->Offset == InputStrings[2].Offset);
+    EXPECT_TRUE(ThirdPtr->getValue()->Index == InputStrings[2].Idx);
+
+    // Check order enumerated strings.
+    uint64_t CurIdx = 0;
+    std::function<void(DwarfStringPoolEntryRef)> checkStr =
+        [&](DwarfStringPoolEntryRef Entry) {
+          EXPECT_TRUE(Entry.getEntry().isIndexed());
+          EXPECT_TRUE(Entry.getIndex() == CurIdx);
+          EXPECT_TRUE(Entry.getOffset() == InputStrings[CurIdx].Offset);
+          EXPECT_TRUE(Entry.getString() == InputStrings[CurIdx].Str);
+
+          CurIdx++;
+        };
+
+    OutStrings.forEach(checkStr);
+  });
 }
 
 TEST(StringPoolTest, TestStringTableWithTranslator) {
@@ -80,25 +87,32 @@
   StringPool Strings;
   StringTable OutStrings(Strings, TranslatorFunc);
 
-  StringEntry *FirstPtr = Strings.insert("first").first;
-  StringEntry *SecondPtr = Strings.insert("second").first;
-  StringEntry *ThirdPtr = Strings.insert("third").first;
+  // StringPool uses PerThreadBumpPtrAllocator which should be accessed from
+  // threads created by ThreadPoolExecutor. Use TaskGroup to run on
+  // ThreadPoolExecutor threads.
+  parallel::TaskGroup tg;
 
-  FirstPtr = OutStrings.add(FirstPtr);
-  SecondPtr = OutStrings.add(SecondPtr);
-  ThirdPtr = OutStrings.add(ThirdPtr);
+  tg.spawn([&]() {
+    StringEntry *FirstPtr = Strings.insert("first").first;
+    StringEntry *SecondPtr = Strings.insert("second").first;
+    StringEntry *ThirdPtr = Strings.insert("third").first;
 
-  EXPECT_TRUE(FirstPtr->getKey() == "tsrif0");
-  EXPECT_TRUE(FirstPtr->getValue()->Offset == 0);
-  EXPECT_TRUE(FirstPtr->getValue()->Index == 0);
+    FirstPtr = OutStrings.add(FirstPtr);
+    SecondPtr = OutStrings.add(SecondPtr);
+    ThirdPtr = OutStrings.add(ThirdPtr);
 
-  EXPECT_TRUE(SecondPtr->getKey() == "dnoces0");
-  EXPECT_TRUE(SecondPtr->getValue()->Offset == 7);
-  EXPECT_TRUE(SecondPtr->getValue()->Index == 1);
+    EXPECT_TRUE(FirstPtr->getKey() == "tsrif0");
+    EXPECT_TRUE(FirstPtr->getValue()->Offset == 0);
+    EXPECT_TRUE(FirstPtr->getValue()->Index == 0);
 
-  EXPECT_TRUE(ThirdPtr->getKey() == "driht0");
-  EXPECT_TRUE(ThirdPtr->getValue()->Offset == 15);
-  EXPECT_TRUE(ThirdPtr->getValue()->Index == 2);
+    EXPECT_TRUE(SecondPtr->getKey() == "dnoces0");
+    EXPECT_TRUE(SecondPtr->getValue()->Offset == 7);
+    EXPECT_TRUE(SecondPtr->getValue()->Index == 1);
+
+    EXPECT_TRUE(ThirdPtr->getKey() == "driht0");
+    EXPECT_TRUE(ThirdPtr->getValue()->Offset == 15);
+    EXPECT_TRUE(ThirdPtr->getValue()->Index == 2);
+  });
 }
 
 } // anonymous namespace
diff --git a/llvm/unittests/Support/CMakeLists.txt b/llvm/unittests/Support/CMakeLists.txt
--- a/llvm/unittests/Support/CMakeLists.txt
+++ b/llvm/unittests/Support/CMakeLists.txt
@@ -63,6 +63,7 @@
   OptimizedStructLayoutTest.cpp
   ParallelTest.cpp
   Path.cpp
+  PerThreadBumpPtrAllocatorTest.cpp
   ProcessTest.cpp
   ProgramTest.cpp
   RegexTest.cpp
diff --git a/llvm/unittests/Support/PerThreadBumpPtrAllocatorTest.cpp b/llvm/unittests/Support/PerThreadBumpPtrAllocatorTest.cpp
new file mode 100644
--- /dev/null
+++ b/llvm/unittests/Support/PerThreadBumpPtrAllocatorTest.cpp
@@ -0,0 +1,56 @@
+//===- PerThreadBumpPtrAllocatorTest.cpp ----------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/PerThreadBumpPtrAllocator.h"
+#include "llvm/Support/Parallel.h"
+#include "gtest/gtest.h"
+#include <cstdlib>
+
+using namespace llvm;
+using namespace parallel;
+
+namespace {
+
+TEST(PerThreadBumpPtrAllocatorTest, Simple) {
+  PerThreadBumpPtrAllocator Allocator;
+
+  parallel::TaskGroup tg;
+
+  tg.spawn([&]() {
+    uint64_t *Var =
+        (uint64_t *)Allocator.Allocate(sizeof(uint64_t), alignof(uint64_t));
+    *Var = 0xFE;
+    EXPECT_EQ(0xFEul, *Var);
+    EXPECT_EQ(sizeof(uint64_t), Allocator.getBytesAllocated());
+    EXPECT_TRUE(Allocator.getBytesAllocated() <= Allocator.getTotalMemory());
+
+    PerThreadBumpPtrAllocator Allocator2(std::move(Allocator));
+
+    EXPECT_EQ(sizeof(uint64_t), Allocator2.getBytesAllocated());
+    EXPECT_TRUE(Allocator2.getBytesAllocated() <= Allocator2.getTotalMemory());
+
+    EXPECT_EQ(0xFEul, *Var);
+  });
+}
+
+TEST(PerThreadBumpPtrAllocatorTest, ParallelAllocation) {
+  PerThreadBumpPtrAllocator Allocator;
+
+  static size_t constexpr NumAllocations = 1000;
+
+  parallelFor(0, NumAllocations, [&](size_t Idx) {
+    uint64_t *ptr =
+        (uint64_t *)Allocator.Allocate(sizeof(uint64_t), alignof(uint64_t));
+    *ptr = Idx;
+  });
+
+  EXPECT_EQ(sizeof(uint64_t) * NumAllocations, Allocator.getBytesAllocated());
+  EXPECT_EQ(Allocator.getNumberOfAllocators(), parallel::getNumThreads());
+}
+
+} // anonymous namespace