Change allocator.

Summary:
There seems to be a gain all over memgraph.
I strongly suggest including this in the codebase.

Link to project:
https://github.com/r-lyeh/ltalloc

Reviewers: teon.banek, mferencevic, mislav.bradac, florijan

Reviewed By: teon.banek

Subscribers: pullbot

Differential Revision: https://phabricator.memgraph.io/D914

CMakeLists.txt

@@ -52,6 +52,10 @@ add_custom_target(clean_all
 # threading
 find_package(Threads REQUIRED)
 
+# optional Ltalloc
+option(USE_LTALLOC "Use Ltalloc instead of default allocator (default ON). \
+Set this to OFF to prevent linking with Ltalloc." ON)
+
 # optional readline
 option(USE_READLINE "Use GNU Readline library if available (default ON). \
 Set this to OFF to prevent linking with Readline even if it is available." ON)
@@ -69,6 +73,7 @@ endif()
 # set(CMAKE_CXX_STANDARD_REQUIRED ON)
 # For now, explicitly set -std= flag for C++17.
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++1z -Wall")
+
 # Don't omit frame pointer in RelWithDebInfo, for additional callchain debug.
 set(CMAKE_CXX_FLAGS_RELWITHDEBINFO
     "${CMAKE_CXX_FLAGS_RELWITHDEBINFO} -fno-omit-frame-pointer")
@@ -215,6 +220,13 @@ set(memgraph_src_files
 # memgraph_lib depend on these libraries
 set(MEMGRAPH_ALL_LIBS stdc++fs Threads::Threads fmt cppitertools
     antlr_opencypher_parser_lib dl glog gflags)
+
+if (USE_LTALLOC)
+    list(APPEND MEMGRAPH_ALL_LIBS ltalloc)
+# TODO(mferencevic): Enable this when clang is updated on apollo.
+#    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -flto")
+endif()
+
 if (READLINE_FOUND)
     list(APPEND MEMGRAPH_ALL_LIBS readline)
 endif()

libs/CMakeLists.txt

@@ -94,6 +94,12 @@ import_external_library(fmt STATIC
   # Skip testing.
   CMAKE_ARGS -DFMT_TEST=OFF)
 
+
+# Setup ltalloc library
+add_library(ltalloc STATIC ltalloc/ltalloc.cc)
+# TODO(mferencevic): Enable this when clang on apollo is updated
+#target_compile_options(ltalloc PUBLIC -flto)
+
 # setup rapidcheck (it cannot be external, since it doesn't have install
 # target)
 set(RC_ENABLE_GTEST ON CACHE BOOL "Build Google Test integration" FORCE)

libs/setup.sh

@@ -107,3 +107,10 @@ cd json
 #wget "https://raw.githubusercontent.com/nlohmann/json/91e003285312167ad8365f387438ea371b465a7e/src/json.hpp"
 wget -nv http://deps.memgraph.io/json.hpp
 cd ..
+
+#ltalloc
+git clone https://github.com/r-lyeh/ltalloc.git
+ltalloc_tag="aefde2afa5cd49c9d1a797aa08ec08b2bec13a36" # Sep 15, 2017
+cd ltalloc
+git checkout ${ltalloc_tag}
+cd ..

src/database/graph_db.cpp

@@ -1,7 +1,5 @@
 #include <functional>
 
-#include <malloc.h>
-
 #include <gflags/gflags.h>
 #include <glog/logging.h>
 
@@ -136,13 +134,6 @@ void GraphDb::CollectGarbage() {
             << x.Elapsed().count();
   }
 
-  {
-    utils::Timer x;
-    malloc_trim(0);
-    VLOG(1) << "Garbage collector malloc trim phase time: "
-            << x.Elapsed().count();
-  }
-
   LOG(INFO) << "Garbage collector finished";
   VLOG(2) << "gc snapshot: " << snapshot;
   VLOG(2) << "edge_record_deleter_ size: " << edge_record_deleter_.Count();