Revert "SERVER-29462 Align locks in mongo::Paritioned to avoid false sharing"

This reverts commit edc858ca3a32974c07f027e6860a52ac6e89039b.

2 files changed, 5 insertions, 78 deletions

diff --git a/src/mongo/db/catalog/util/partitioned.h b/src/mongo/db/catalog/util/partitioned.h
index ab960cc7cc1..475ea415f48 100644
--- a/src/mongo/db/catalog/util/partitioned.h
+++ b/src/mongo/db/catalog/util/partitioned.h
@@ -29,7 +29,6 @@
 #pragma once
 
 #include <algorithm>
-#include <array>
 #include <cstdlib>
 #include <iterator>
 #include <memory>
@@ -40,9 +39,7 @@
 #include "mongo/platform/atomic_word.h"
 #include "mongo/stdx/memory.h"
 #include "mongo/stdx/mutex.h"
-#include "mongo/stdx/new.h"
 #include "mongo/util/assert_util.h"
-#include "mongo/util/with_alignment.h"
 
 namespace mongo {
 
@@ -103,8 +100,6 @@ struct Partitioner {
 
 namespace partitioned_detail {
 
-using CacheAlignedMutex = CacheAligned<stdx::mutex>;
-
 template <typename Key, typename Value>
 Key getKey(const std::pair<Key, Value>& pair) {
     return std::get<0>(pair);
@@ -115,10 +110,9 @@ Key getKey(const Key& key) {
     return key;
 }
 
-template <typename T>
-inline std::vector<stdx::unique_lock<stdx::mutex>> lockAllPartitions(T& mutexes) {
+inline std::vector<stdx::unique_lock<stdx::mutex>> lockAllPartitions(
+    std::vector<stdx::mutex>& mutexes) {
     std::vector<stdx::unique_lock<stdx::mutex>> result;
-    result.reserve(mutexes.size());
     std::transform(mutexes.begin(), mutexes.end(), std::back_inserter(result), [](auto&& mutex) {
         return stdx::unique_lock<stdx::mutex>{mutex};
     });
@@ -381,14 +375,12 @@ public:
     /**
      * Constructs a partitioned version of a AssociativeContainer, with `nPartitions` partitions.
      */
-    Partitioned() = default;
+    Partitioned() : _mutexes(nPartitions), _partitions(nPartitions) {}
 
 private:
     // These two vectors parallel each other, but we keep them separate so that we can return an
     // iterator over `_partitions` from within All.
-    mutable std::array<partitioned_detail::CacheAlignedMutex, nPartitions> _mutexes;
-
-    using CacheAlignedAssociativeContainer = CacheAligned<AssociativeContainer>;
-    std::array<CacheAlignedAssociativeContainer, nPartitions> _partitions;
+    mutable std::vector<stdx::mutex> _mutexes;
+    std::vector<AssociativeContainer> _partitions;
 };
 }  // namespace mongo
diff --git a/src/mongo/util/with_alignment.h b/src/mongo/util/with_alignment.h
deleted file mode 100644
index b1128f527ff..00000000000
--- a/src/mongo/util/with_alignment.h
+++ /dev/null
@@ -1,65 +0,0 @@
-/**
- * Copyright (C) 2017 MongoDB Inc.
- *
- * This program is free software: you can redistribute it and/or  modify
- * it under the terms of the GNU Affero General Public License, version 3,
- * as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
- * As a special exception, the copyright holders give permission to link the
- * code of portions of this program with the OpenSSL library under certain
- * conditions as described in each individual source file and distribute
- * linked combinations including the program with the OpenSSL library. You
- * must comply with the GNU Affero General Public License in all respects
- * for all of the code used other than as permitted herein. If you modify
- * file(s) with this exception, you may extend this exception to your
- * version of the file(s), but you are not obligated to do so. If you do not
- * wish to do so, delete this exception statement from your version. If you
- * delete this exception statement from all source files in the program,
- * then also delete it in the license file.
- */
-
-#pragma once
-
-#include <algorithm>
-
-#include "mongo/stdx/new.h"
-
-namespace mongo {
-
-/**
- * Creates a new type with the same interface as T, but having the
- * given alignment. Note that if the given alignment is less than
- * alignof(T), the program is ill-formed. To ensure that your program
- * is well formed, see WithAligmentAtLeast, which will not reduce
- * alignment below the natural alignment of T.
- */
-template <typename T, size_t alignment>
-struct alignas(alignment) WithAlignment : T {
-    using T::T;
-};
-
-/**
- * Creates a new type with the same interface as T, but having an
- * alignment greater than or equal to the given alignment. To ensure
- * that the program remains well formed, the alignment will not be
- * reduced below the natural alignment for T.
- */
-template <typename T, size_t alignment>
-using WithAlignmentAtLeast = WithAlignment<T, std::max(alignof(T), alignment)>;
-
-/**
- * Creates a new type with the same interface as T but guaranteed to
- * be aligned to at least the size of a cache line.
- */
-template <typename T>
-using CacheAligned = WithAlignmentAtLeast<T, stdx::hardware_destructive_interference_size>;
-
-}  // namespace mongo