libtcmalloc-sys 0.1.14

diff --git a/tcmalloc/system-alloc.cc b/tcmalloc/system-alloc.cc
index a81677ef..381d1acd 100644
--- a/tcmalloc/system-alloc.cc
+++ b/tcmalloc/system-alloc.cc
@@ -32,6 +32,7 @@
 #include "absl/numeric/bits.h"
 #include "absl/types/span.h"
 #include "tcmalloc/internal/config.h"
+#include "tcmalloc/internal/environment.h"
 #include "tcmalloc/internal/logging.h"
 #include "tcmalloc/internal/page_size.h"
 #include "tcmalloc/malloc_extension.h"
@@ -103,3 +104,27 @@ int MapFixedNoReplaceFlagAvailable() {
 
 }  // namespace tcmalloc::tcmalloc_internal::system_allocator_internal
 GOOGLE_MALLOC_SECTION_END
+
+namespace rust_patches {
+#ifdef RUST_PATCHES_DISABLE_MADV_HUGEPAGE_BY_VAR
+[[nodiscard]] bool should_not_madvise_hugepage() {
+  ABSL_CONST_INIT static std::atomic<bool> result {false};
+  ABSL_CONST_INIT static absl::once_flag flag;
+  absl::base_internal::LowLevelCallOnce(&flag, [&]() {
+    const char* e = tcmalloc::tcmalloc_internal::thread_safe_getenv("TCMALLOC_DISABLE_MADV_HUGEPAGE");
+    if (e) {
+      switch (e[0]) {
+        case '0':
+          break;
+        case '1':
+          result.store(true, std::memory_order_release);
+          break;
+        default:
+          TC_BUG("bad env var TCMALLOC_DISABLE_MADV_HUGEPAGE value = '%s'", e);
+      }
+    }
+  });
+  return result.load(std::memory_order_acquire);
+}
+#endif // RUST_PATCHES_DISABLE_MADV_HUGEPAGE_BY_VAR
+} // namespace rust_patches
diff --git a/tcmalloc/system-alloc.h b/tcmalloc/system-alloc.h
index 51283aa8..add0fa62 100644
--- a/tcmalloc/system-alloc.h
+++ b/tcmalloc/system-alloc.h
@@ -61,6 +61,20 @@
 #define PR_SET_VMA_ANON_NAME 0
 #endif
 
+namespace rust_patches {
+#ifdef RUST_PATCHES_DISABLE_MADV_HUGEPAGE_ALWAYS
+[[nodiscard]] constexpr bool should_not_madvise_hugepage() {
+  return true;
+}
+#elif defined(RUST_PATCHES_DISABLE_MADV_HUGEPAGE_BY_VAR)
+[[nodiscard]] bool should_not_madvise_hugepage();
+#else
+[[nodiscard]] constexpr bool should_not_madvise_hugepage() {
+  return false;
+}
+#endif
+} // namespace rust_patches
+
 GOOGLE_MALLOC_SECTION_BEGIN
 namespace tcmalloc {
 namespace tcmalloc_internal {
@@ -508,6 +522,7 @@ void* SystemAllocator<Topology>::MmapAlignedLocked(size_t size,
     next_addr = RandomMmapHint(size, alignment, tag);
   }
   const int map_fixed_noreplace_flag = MapFixedNoReplaceFlagAvailable();
+  const bool should_not_madvise_hugepage_flag = rust_patches::should_not_madvise_hugepage();
   void* hint;
   // Avoid clobbering errno, especially if an initial mmap fails but a
   // subsequent one succeeds.  If we fail to allocate memory, MallocOomPolicy
@@ -520,6 +535,11 @@ void* SystemAllocator<Topology>::MmapAlignedLocked(size_t size,
 
     void* result = mmap(hint, size, PROT_NONE, flags, -1, 0);
     if (result == hint) {
+      if (!should_not_madvise_hugepage_flag) {
+        // Avoid clobbering errno. Ignore if madvise fails.
+        ErrnoRestorer errno_restorer_madv;
+        madvise(result, size, MADV_HUGEPAGE);
+      }
       if (numa_partition.has_value()) {
         BindMemory(result, size, *numa_partition);
       }