[PATCH] D44261: [sanitizer] Align & pad the allocator structures to the cacheline size

[Kostya Kortchinsky via Phabricator via llvm-commits]

cryptoad updated this revision to Diff 137635.
cryptoad marked an inline comment as done.
cryptoad added a comment.

Addressing the other comment.


Repository:
  rCRT Compiler Runtime

https://reviews.llvm.org/D44261

Files:
  lib/sanitizer_common/sanitizer_allocator_primary32.h
  lib/sanitizer_common/sanitizer_allocator_primary64.h
  lib/sanitizer_common/sanitizer_common.h


Index: lib/sanitizer_common/sanitizer_common.h
===================================================================
--- lib/sanitizer_common/sanitizer_common.h
+++ lib/sanitizer_common/sanitizer_common.h
@@ -40,10 +40,12 @@
 const uptr kWordSizeInBits = 8 * kWordSize;
 
 #if defined(__powerpc__) || defined(__powerpc64__)
-  const uptr kCacheLineSize = 128;
+  constexpr uptr kCacheLineSize = 128;
 #else
-  const uptr kCacheLineSize = 64;
+  constexpr uptr kCacheLineSize = 64;
 #endif
+// Check that the CacheLine size is a power-of-two.
+COMPILER_CHECK((kCacheLineSize & (kCacheLineSize - 1)) == 0);
 
 const uptr kMaxPathLength = 4096;
 
Index: lib/sanitizer_common/sanitizer_allocator_primary64.h
===================================================================
--- lib/sanitizer_common/sanitizer_allocator_primary64.h
+++ lib/sanitizer_common/sanitizer_allocator_primary64.h
@@ -80,6 +80,8 @@
     }
     SetReleaseToOSIntervalMs(release_to_os_interval_ms);
     MapWithCallbackOrDie(SpaceEnd(), AdditionalSize());
+    // Check that the RegionInfo array is aligned on the CacheLine size.
+    DCHECK_EQ(SpaceEnd() & (kCacheLineSize - 1), 0);
   }
 
   s32 ReleaseToOSIntervalMs() const {
@@ -302,7 +304,7 @@
 
   static uptr AdditionalSize() {
     return RoundUpTo(sizeof(RegionInfo) * kNumClassesRounded,
-                     GetPageSizeCached());
+        GetPageSizeCached());
   }
 
   typedef SizeClassMap SizeClassMapT;
@@ -584,7 +586,7 @@
     u64 last_released_bytes;
   };
 
-  struct RegionInfo {
+  struct ALIGNED(kCacheLineSize) RegionInfo {
     BlockingMutex mutex;
     uptr num_freed_chunks;  // Number of elements in the freearray.
     uptr mapped_free_array;  // Bytes mapped for freearray.
@@ -597,12 +599,11 @@
     Stats stats;
     ReleaseToOsInfo rtoi;
   };
-  COMPILER_CHECK(sizeof(RegionInfo) >= kCacheLineSize);
+  COMPILER_CHECK(sizeof(RegionInfo) % kCacheLineSize == 0);
 
   RegionInfo *GetRegionInfo(uptr class_id) const {
-    CHECK_LT(class_id, kNumClasses);
-    RegionInfo *regions =
-        reinterpret_cast<RegionInfo *>(SpaceBeg() + kSpaceSize);
+    DCHECK_LT(class_id, kNumClasses);
+    RegionInfo *regions = reinterpret_cast<RegionInfo *>(SpaceEnd());
     return &regions[class_id];
   }
 
Index: lib/sanitizer_common/sanitizer_allocator_primary32.h
===================================================================
--- lib/sanitizer_common/sanitizer_allocator_primary32.h
+++ lib/sanitizer_common/sanitizer_allocator_primary32.h
@@ -266,14 +266,12 @@
   static const uptr kRegionSize = 1 << kRegionSizeLog;
   static const uptr kNumPossibleRegions = kSpaceSize / kRegionSize;
 
-  struct SizeClassInfo {
+  struct ALIGNED(kCacheLineSize) SizeClassInfo {
     SpinMutex mutex;
     IntrusiveList<TransferBatch> free_list;
     u32 rand_state;
-    char padding[kCacheLineSize - 2 * sizeof(uptr) -
-                 sizeof(IntrusiveList<TransferBatch>)];
   };
-  COMPILER_CHECK(sizeof(SizeClassInfo) == kCacheLineSize);
+  COMPILER_CHECK(sizeof(SizeClassInfo) % kCacheLineSize == 0);
 
   uptr ComputeRegionId(uptr mem) {
     const uptr res = mem >> kRegionSizeLog;
@@ -299,7 +297,7 @@
   }
 
   SizeClassInfo *GetSizeClassInfo(uptr class_id) {
-    CHECK_LT(class_id, kNumClasses);
+    DCHECK_LT(class_id, kNumClasses);
     return &size_class_info_array[class_id];
   }
 


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