[compiler-rt] r208878 - tsan: allow to disable history collection

[Dmitry Vyukov]

Author: dvyukov
Date: Thu May 15 07:51:48 2014
New Revision: 208878

URL: http://llvm.org/viewvc/llvm-project?rev=208878&view=rev
Log:
tsan: allow to disable history collection
The mode is enabled with -DTSAN_NO_HISTORY=1 flag.
Intended mostly for research purposes (how fast can it go w/o history).


Modified:
    compiler-rt/trunk/lib/tsan/rtl/tsan_defs.h
    compiler-rt/trunk/lib/tsan/rtl/tsan_rtl.cc
    compiler-rt/trunk/lib/tsan/rtl/tsan_rtl.h

Modified: compiler-rt/trunk/lib/tsan/rtl/tsan_defs.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_defs.h?rev=208878&r1=208877&r2=208878&view=diff
==============================================================================
--- compiler-rt/trunk/lib/tsan/rtl/tsan_defs.h (original)
+++ compiler-rt/trunk/lib/tsan/rtl/tsan_defs.h Thu May 15 07:51:48 2014
@@ -66,6 +66,12 @@ const uptr kShadowSize = 8;
 // Shadow memory is kShadowMultiplier times larger than user memory.
 const uptr kShadowMultiplier = kShadowSize * kShadowCnt / kShadowCell;
 
+#if defined(TSAN_NO_HISTORY) && TSAN_NO_HISTORY
+const bool kCollectHistory = false;
+#else
+const bool kCollectHistory = true;
+#endif
+
 #if defined(TSAN_COLLECT_STATS) && TSAN_COLLECT_STATS
 const bool kCollectStats = true;
 #else

Modified: compiler-rt/trunk/lib/tsan/rtl/tsan_rtl.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_rtl.cc?rev=208878&r1=208877&r2=208878&view=diff
==============================================================================
--- compiler-rt/trunk/lib/tsan/rtl/tsan_rtl.cc (original)
+++ compiler-rt/trunk/lib/tsan/rtl/tsan_rtl.cc Thu May 15 07:51:48 2014
@@ -594,17 +594,19 @@ void MemoryAccess(ThreadState *thr, uptr
   FastState fast_state = thr->fast_state;
   if (fast_state.GetIgnoreBit())
     return;
-  fast_state.IncrementEpoch();
-  thr->fast_state = fast_state;
+  if (kCollectHistory) {
+    fast_state.IncrementEpoch();
+    thr->fast_state = fast_state;
+    // We must not store to the trace if we do not store to the shadow.
+    // That is, this call must be moved somewhere below.
+    TraceAddEvent(thr, fast_state, EventTypeMop, pc);
+  }
+
   Shadow cur(fast_state);
   cur.SetAddr0AndSizeLog(addr & 7, kAccessSizeLog);
   cur.SetWrite(kAccessIsWrite);
   cur.SetAtomic(kIsAtomic);
 
-  // We must not store to the trace if we do not store to the shadow.
-  // That is, this call must be moved somewhere below.
-  TraceAddEvent(thr, fast_state, EventTypeMop, pc);
-
   MemoryAccessImpl(thr, addr, kAccessSizeLog, kAccessIsWrite, kIsAtomic,
       shadow_mem, cur);
 }
@@ -684,8 +686,10 @@ void MemoryRangeFreed(ThreadState *thr,
   thr->is_freeing = true;
   MemoryAccessRange(thr, pc, addr, size, true);
   thr->is_freeing = false;
-  thr->fast_state.IncrementEpoch();
-  TraceAddEvent(thr, thr->fast_state, EventTypeMop, pc);
+  if (kCollectHistory) {
+    thr->fast_state.IncrementEpoch();
+    TraceAddEvent(thr, thr->fast_state, EventTypeMop, pc);
+  }
   Shadow s(thr->fast_state);
   s.ClearIgnoreBit();
   s.MarkAsFreed();
@@ -695,8 +699,10 @@ void MemoryRangeFreed(ThreadState *thr,
 }
 
 void MemoryRangeImitateWrite(ThreadState *thr, uptr pc, uptr addr, uptr size) {
-  thr->fast_state.IncrementEpoch();
-  TraceAddEvent(thr, thr->fast_state, EventTypeMop, pc);
+  if (kCollectHistory) {
+    thr->fast_state.IncrementEpoch();
+    TraceAddEvent(thr, thr->fast_state, EventTypeMop, pc);
+  }
   Shadow s(thr->fast_state);
   s.ClearIgnoreBit();
   s.SetWrite(true);
@@ -708,8 +714,10 @@ ALWAYS_INLINE USED
 void FuncEntry(ThreadState *thr, uptr pc) {
   StatInc(thr, StatFuncEnter);
   DPrintf2("#%d: FuncEntry %p\n", (int)thr->fast_state.tid(), (void*)pc);
-  thr->fast_state.IncrementEpoch();
-  TraceAddEvent(thr, thr->fast_state, EventTypeFuncEnter, pc);
+  if (kCollectHistory) {
+    thr->fast_state.IncrementEpoch();
+    TraceAddEvent(thr, thr->fast_state, EventTypeFuncEnter, pc);
+  }
 
   // Shadow stack maintenance can be replaced with
   // stack unwinding during trace switch (which presumably must be faster).
@@ -737,8 +745,10 @@ ALWAYS_INLINE USED
 void FuncExit(ThreadState *thr) {
   StatInc(thr, StatFuncExit);
   DPrintf2("#%d: FuncExit\n", (int)thr->fast_state.tid());
-  thr->fast_state.IncrementEpoch();
-  TraceAddEvent(thr, thr->fast_state, EventTypeFuncExit, 0);
+  if (kCollectHistory) {
+    thr->fast_state.IncrementEpoch();
+    TraceAddEvent(thr, thr->fast_state, EventTypeFuncExit, 0);
+  }
 
   DCHECK_GT(thr->shadow_stack_pos, thr->shadow_stack);
 #ifndef TSAN_GO

Modified: compiler-rt/trunk/lib/tsan/rtl/tsan_rtl.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_rtl.h?rev=208878&r1=208877&r2=208878&view=diff
==============================================================================
--- compiler-rt/trunk/lib/tsan/rtl/tsan_rtl.h (original)
+++ compiler-rt/trunk/lib/tsan/rtl/tsan_rtl.h Thu May 15 07:51:48 2014
@@ -776,6 +776,8 @@ Trace *ThreadTrace(int tid);
 extern "C" void __tsan_trace_switch();
 void ALWAYS_INLINE TraceAddEvent(ThreadState *thr, FastState fs,
                                         EventType typ, u64 addr) {
+  if (!kCollectHistory)
+    return;
   DCHECK_GE((int)typ, 0);
   DCHECK_LE((int)typ, 7);
   DCHECK_EQ(GetLsb(addr, 61), addr);