diff --git a/compiler-rt/lib/tsan/rtl/tsan_interface_atomic.cpp b/compiler-rt/lib/tsan/rtl/tsan_interface_atomic.cpp
--- a/compiler-rt/lib/tsan/rtl/tsan_interface_atomic.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_interface_atomic.cpp
@@ -268,7 +268,7 @@
     return;
   }
   __sync_synchronize();
-  SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, (uptr)a);
+  SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, (uptr)a, false);
   Lock l(&s->mtx);
   thr->fast_state.IncrementEpoch();
   // Can't increment epoch w/o writing to the trace as well.
@@ -282,7 +282,7 @@
   MemoryWriteAtomic(thr, pc, (uptr)a, SizeLog<T>());
   if (LIKELY(mo == mo_relaxed))
     return F(a, v);
-  SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, (uptr)a);
+  SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, (uptr)a, false);
   Lock l(&s->mtx);
   thr->fast_state.IncrementEpoch();
   // Can't increment epoch w/o writing to the trace as well.
@@ -415,7 +415,7 @@
   }
 
   bool release = IsReleaseOrder(mo);
-  SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, (uptr)a);
+  SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, (uptr)a, false);
   RWLock l(&s->mtx, release);
   T cc = *c;
   T pr = func_cas(a, cc, v);
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cpp b/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cpp
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cpp
@@ -71,9 +71,10 @@
     MemoryWrite(thr, pc, addr, kSizeLog1);
     thr->is_freeing = false;
   }
-  SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr);
+  SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, true);
   Lock l(&s->mtx);
   s->SetFlags(flagz & MutexCreationFlagMask);
+  // Save stack in the case the sync object was created before as atomic.
   if (!SANITIZER_GO && s->creation_stack_id == 0)
     s->creation_stack_id = CurrentStackId(thr, pc);
 }
@@ -143,7 +144,7 @@
 void MutexPreLock(ThreadState *thr, uptr pc, uptr addr, u32 flagz) {
   DPrintf("#%d: MutexPreLock %zx flagz=0x%x\n", thr->tid, addr, flagz);
   if (!(flagz & MutexFlagTryLock) && common_flags()->detect_deadlocks) {
-    SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr);
+    SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, true);
     {
       ReadLock l(&s->mtx);
       s->UpdateFlags(flagz);
@@ -171,7 +172,7 @@
   bool first = false;
   bool report_double_lock = false;
   {
-    SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr);
+    SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, true);
     Lock l(&s->mtx);
     s->UpdateFlags(flagz);
     thr->fast_state.IncrementEpoch();
@@ -221,7 +222,7 @@
   bool report_bad_unlock = false;
   int rec = 0;
   {
-    SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr);
+    SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, true);
     Lock l(&s->mtx);
     thr->fast_state.IncrementEpoch();
     TraceAddEvent(thr, thr->fast_state, EventTypeUnlock, s->GetId());
@@ -260,7 +261,7 @@
   DPrintf("#%d: MutexPreReadLock %zx flagz=0x%x\n", thr->tid, addr, flagz);
   if (!(flagz & MutexFlagTryLock) && common_flags()->detect_deadlocks) {
     {
-      SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr);
+      SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, true);
       ReadLock l(&s->mtx);
       s->UpdateFlags(flagz);
       Callback cb(thr, pc);
@@ -279,7 +280,7 @@
   bool report_bad_lock = false;
   bool pre_lock = false;
   {
-    SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr);
+    SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, true);
     ReadLock l(&s->mtx);
     s->UpdateFlags(flagz);
     thr->fast_state.IncrementEpoch();
@@ -318,7 +319,7 @@
   u64 mid = 0;
   bool report_bad_unlock = false;
   {
-    SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr);
+    SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, true);
     Lock l(&s->mtx);
     thr->fast_state.IncrementEpoch();
     TraceAddEvent(thr, thr->fast_state, EventTypeRUnlock, s->GetId());
@@ -351,7 +352,7 @@
   u64 mid = 0;
   bool report_bad_unlock = false;
   {
-    SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr);
+    SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, true);
     Lock l(&s->mtx);
     bool write = true;
     if (s->owner_tid == kInvalidTid) {
@@ -392,7 +393,7 @@
 
 void MutexRepair(ThreadState *thr, uptr pc, uptr addr) {
   DPrintf("#%d: MutexRepair %zx\n", thr->tid, addr);
-  SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr);
+  SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, true);
   Lock l(&s->mtx);
   s->owner_tid = kInvalidTid;
   s->recursion = 0;
@@ -400,7 +401,7 @@
 
 void MutexInvalidAccess(ThreadState *thr, uptr pc, uptr addr) {
   DPrintf("#%d: MutexInvalidAccess %zx\n", thr->tid, addr);
-  SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr);
+  SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, true);
   ReportMutexMisuse(thr, pc, ReportTypeMutexInvalidAccess, addr, s->GetId());
 }
 
@@ -438,7 +439,7 @@
   DPrintf("#%d: ReleaseStoreAcquire %zx\n", thr->tid, addr);
   if (thr->ignore_sync)
     return;
-  SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr);
+  SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, false);
   Lock l(&s->mtx);
   thr->fast_state.IncrementEpoch();
   // Can't increment epoch w/o writing to the trace as well.
@@ -450,7 +451,7 @@
   DPrintf("#%d: Release %zx\n", thr->tid, addr);
   if (thr->ignore_sync)
     return;
-  SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr);
+  SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, false);
   Lock l(&s->mtx);
   thr->fast_state.IncrementEpoch();
   // Can't increment epoch w/o writing to the trace as well.
@@ -462,7 +463,7 @@
   DPrintf("#%d: ReleaseStore %zx\n", thr->tid, addr);
   if (thr->ignore_sync)
     return;
-  SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr);
+  SyncVar *s = ctx->metamap.GetSyncOrCreate(thr, pc, addr, false);
   Lock l(&s->mtx);
   thr->fast_state.IncrementEpoch();
   // Can't increment epoch w/o writing to the trace as well.
diff --git a/compiler-rt/lib/tsan/rtl/tsan_sync.h b/compiler-rt/lib/tsan/rtl/tsan_sync.h
--- a/compiler-rt/lib/tsan/rtl/tsan_sync.h
+++ b/compiler-rt/lib/tsan/rtl/tsan_sync.h
@@ -64,7 +64,7 @@
   // with the mtx. This reduces contention for hot sync objects.
   SyncClock clock;
 
-  void Init(ThreadState *thr, uptr pc, uptr addr, u64 uid);
+  void Init(ThreadState *thr, uptr pc, uptr addr, u64 uid, bool save_stack);
   void Reset(Processor *proc);
 
   u64 GetId() const {
@@ -115,11 +115,12 @@
   void ResetRange(Processor *proc, uptr p, uptr sz);
   MBlock* GetBlock(uptr p);
 
-  SyncVar *GetSyncOrCreate(ThreadState *thr, uptr pc, uptr addr) {
-    return GetSync(thr, pc, addr, true);
+  SyncVar *GetSyncOrCreate(ThreadState *thr, uptr pc, uptr addr,
+                           bool save_stack) {
+    return GetSync(thr, pc, addr, true, save_stack);
   }
   SyncVar *GetSyncIfExists(uptr addr) {
-    return GetSync(nullptr, 0, addr, false);
+    return GetSync(nullptr, 0, addr, false, false);
   }
 
   void MoveMemory(uptr src, uptr dst, uptr sz);
@@ -136,7 +137,8 @@
   SyncAlloc sync_alloc_;
   atomic_uint64_t uid_gen_;
 
-  SyncVar *GetSync(ThreadState *thr, uptr pc, uptr addr, bool create);
+  SyncVar *GetSync(ThreadState *thr, uptr pc, uptr addr, bool create,
+                   bool save_stack);
 };
 
 }  // namespace __tsan
diff --git a/compiler-rt/lib/tsan/rtl/tsan_sync.cpp b/compiler-rt/lib/tsan/rtl/tsan_sync.cpp
--- a/compiler-rt/lib/tsan/rtl/tsan_sync.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_sync.cpp
@@ -20,13 +20,14 @@
 
 SyncVar::SyncVar() : mtx(MutexTypeSyncVar) { Reset(0); }
 
-void SyncVar::Init(ThreadState *thr, uptr pc, uptr addr, u64 uid) {
+void SyncVar::Init(ThreadState *thr, uptr pc, uptr addr, u64 uid,
+                   bool save_stack) {
   this->addr = addr;
   this->uid = uid;
   this->next = 0;
 
   creation_stack_id = 0;
-  if (!SANITIZER_GO)  // Go does not use them
+  if (save_stack && !SANITIZER_GO)  // Go does not use them
     creation_stack_id = CurrentStackId(thr, pc);
   if (common_flags()->detect_deadlocks)
     DDMutexInit(thr, pc, this);
@@ -190,7 +191,8 @@
   }
 }
 
-SyncVar *MetaMap::GetSync(ThreadState *thr, uptr pc, uptr addr, bool create) {
+SyncVar *MetaMap::GetSync(ThreadState *thr, uptr pc, uptr addr, bool create,
+                          bool save_stack) {
   u32 *meta = MemToMeta(addr);
   u32 idx0 = *meta;
   u32 myidx = 0;
@@ -219,7 +221,7 @@
       const u64 uid = atomic_fetch_add(&uid_gen_, 1, memory_order_relaxed);
       myidx = sync_alloc_.Alloc(&thr->proc()->sync_cache);
       mys = sync_alloc_.Map(myidx);
-      mys->Init(thr, pc, addr, uid);
+      mys->Init(thr, pc, addr, uid, save_stack);
     }
     mys->next = idx0;
     if (atomic_compare_exchange_strong((atomic_uint32_t*)meta, &idx0,
diff --git a/compiler-rt/lib/tsan/tests/unit/tsan_sync_test.cpp b/compiler-rt/lib/tsan/tests/unit/tsan_sync_test.cpp
--- a/compiler-rt/lib/tsan/tests/unit/tsan_sync_test.cpp
+++ b/compiler-rt/lib/tsan/tests/unit/tsan_sync_test.cpp
@@ -57,10 +57,10 @@
   m->AllocBlock(thr, 0, (uptr)&block[0], 4 * sizeof(u64));
   SyncVar *s1 = m->GetSyncIfExists((uptr)&block[0]);
   EXPECT_EQ(s1, (SyncVar*)0);
-  s1 = m->GetSyncOrCreate(thr, 0, (uptr)&block[0]);
+  s1 = m->GetSyncOrCreate(thr, 0, (uptr)&block[0], false);
   EXPECT_NE(s1, (SyncVar*)0);
   EXPECT_EQ(s1->addr, (uptr)&block[0]);
-  SyncVar *s2 = m->GetSyncOrCreate(thr, 0, (uptr)&block[1]);
+  SyncVar *s2 = m->GetSyncOrCreate(thr, 0, (uptr)&block[1], false);
   EXPECT_NE(s2, (SyncVar*)0);
   EXPECT_EQ(s2->addr, (uptr)&block[1]);
   m->FreeBlock(thr->proc(), (uptr)&block[0]);
@@ -79,8 +79,8 @@
   u64 block2[4] = {};  // fake malloc block
   m->AllocBlock(thr, 0, (uptr)&block1[0], 3 * sizeof(u64));
   m->AllocBlock(thr, 0, (uptr)&block1[3], 1 * sizeof(u64));
-  SyncVar *s1 = m->GetSyncOrCreate(thr, 0, (uptr)&block1[0]);
-  SyncVar *s2 = m->GetSyncOrCreate(thr, 0, (uptr)&block1[1]);
+  SyncVar *s1 = m->GetSyncOrCreate(thr, 0, (uptr)&block1[0], false);
+  SyncVar *s2 = m->GetSyncOrCreate(thr, 0, (uptr)&block1[1], false);
   m->MoveMemory((uptr)&block1[0], (uptr)&block2[0], 4 * sizeof(u64));
   MBlock *mb1 = m->GetBlock((uptr)&block1[0]);
   EXPECT_EQ(mb1, (MBlock*)0);
@@ -111,7 +111,7 @@
   MetaMap *m = &ctx->metamap;
   u64 block[1] = {};  // fake malloc block
   m->AllocBlock(thr, 0, (uptr)&block[0], 1 * sizeof(u64));
-  SyncVar *s = m->GetSyncOrCreate(thr, 0, (uptr)&block[0]);
+  SyncVar *s = m->GetSyncOrCreate(thr, 0, (uptr)&block[0], false);
   s->Reset(thr->proc());
   uptr sz = m->FreeBlock(thr->proc(), (uptr)&block[0]);
   EXPECT_EQ(sz, 1 * sizeof(u64));