[compiler-rt] r301927 - tsan: allow fast large MemoryRangeSet on non-Windows Go

[Dmitry Vyukov via llvm-commits]

Author: dvyukov
Date: Tue May  2 10:15:45 2017
New Revision: 301927

URL: http://llvm.org/viewvc/llvm-project?rev=301927&view=rev
Log:
tsan: allow fast large MemoryRangeSet on non-Windows Go

The fast reset for large memory regions is not working
only on windows. So enable it for Go/linux/darwin/freebsd.

See https://github.com/golang/go/issues/20139
for background and motivation.

Based on idea by Josh Bleecher Snyder.


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

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=301927&r1=301926&r2=301927&view=diff
==============================================================================
--- compiler-rt/trunk/lib/tsan/rtl/tsan_rtl.cc (original)
+++ compiler-rt/trunk/lib/tsan/rtl/tsan_rtl.cc Tue May  2 10:15:45 2017
@@ -866,9 +866,8 @@ static void MemoryRangeSet(ThreadState *
   // Don't want to touch lots of shadow memory.
   // If a program maps 10MB stack, there is no need reset the whole range.
   size = (size + (kShadowCell - 1)) & ~(kShadowCell - 1);
-  // UnmapOrDie/MmapFixedNoReserve does not work on Windows,
-  // so we do it only for C/C++.
-  if (SANITIZER_GO || size < common_flags()->clear_shadow_mmap_threshold) {
+  // UnmapOrDie/MmapFixedNoReserve does not work on Windows.
+  if (SANITIZER_WINDOWS || size < common_flags()->clear_shadow_mmap_threshold) {
     u64 *p = (u64*)MemToShadow(addr);
     CHECK(IsShadowMem((uptr)p));
     CHECK(IsShadowMem((uptr)(p + size * kShadowCnt / kShadowCell - 1)));