align atomics to cache line

utcs-scea · Mar 21, 2024 · dbbaa02 · dbbaa02
1 parent 68ef517
commit dbbaa02
Showing 1 changed file with 12 additions and 2 deletions.
diff --git a/libgalois/include/galois/graphs/LS_LC_CSR_Graph.h b/libgalois/include/galois/graphs/LS_LC_CSR_Graph.h
@@ -24,6 +24,7 @@
 #include <iterator>
 #include <cstddef>
 #include <atomic>
+#include <new>
 
 #include <boost/range/iterator_range_core.hpp>
 #include <boost/range/counting_range.hpp>
@@ -32,6 +33,12 @@
 #include "galois/config.h"
 #include "galois/LargeVector.h"
 
+#ifdef __cpp_lib_hardware_interference_size
+using std::hardware_destructive_interference_size;
+#else
+constexpr std::size_t hardware_destructive_interference_size = 64;
+#endif
+
 namespace galois::graphs {
 
 /**
@@ -74,8 +81,11 @@ class LS_LC_CSR_Graph : private boost::noncopyable {
   std::vector<VertexMetadata> m_vertices;
   LargeVector<EdgeMetadata> m_edges[2];
   SpinLock m_edges_lock; // guards resizing of edges vectors
-  std::atomic_uint64_t m_edges_tail = ATOMIC_VAR_INIT(0);
-  std::atomic_uint64_t m_holes      = ATOMIC_VAR_INIT(0);
+
+  alignas(hardware_destructive_interference_size) std::atomic_uint64_t
+      m_edges_tail = ATOMIC_VAR_INIT(0);
+  alignas(hardware_destructive_interference_size) std::atomic_uint64_t m_holes =
+      ATOMIC_VAR_INIT(0);
 
   // returns a reference to the metadata for the pointed-to edge
   inline EdgeMetadata& getEdgeMetadata(EdgeHandle const& handle) {