From 7769d75088976a3735797f9827184315d3bf21d8 Mon Sep 17 00:00:00 2001
From: Azat Khuzhin <a3at.mail@gmail.com>
Date: Wed, 3 Nov 2021 08:11:36 +0300
Subject: [PATCH] Log size of remapped memory (remap_executable)

---
 programs/server/Server.cpp     | 4 ++--
 src/Common/remapExecutable.cpp | 9 +++++----
 src/Common/remapExecutable.h   | 6 +++++-
 3 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/programs/server/Server.cpp b/programs/server/Server.cpp
index af1686bfa70..29845f23d92 100644
--- a/programs/server/Server.cpp
+++ b/programs/server/Server.cpp
@@ -595,8 +595,8 @@ if (ThreadFuzzer::instance().isEffective())
         if (config().getBool("remap_executable", false))
         {
             LOG_DEBUG(log, "Will remap executable in memory.");
-            remapExecutable();
-            LOG_DEBUG(log, "The code in memory has been successfully remapped.");
+            size_t size = remapExecutable();
+            LOG_DEBUG(log, "The code ({}) in memory has been successfully remapped.", ReadableSize(size));
         }
 
         if (config().getBool("mlock_executable", false))
diff --git a/src/Common/remapExecutable.cpp b/src/Common/remapExecutable.cpp
index a774b1028d5..0c1cb03457f 100644
--- a/src/Common/remapExecutable.cpp
+++ b/src/Common/remapExecutable.cpp
@@ -1,3 +1,5 @@
+#include "remapExecutable.h"
+
 #if defined(__linux__) && defined(__amd64__) && defined(__SSE2__) && !defined(SANITIZER) && defined(NDEBUG) && !defined(SPLIT_SHARED_LIBRARIES)
 
 #include <sys/mman.h>
@@ -11,8 +13,6 @@
 #include <Common/Exception.h>
 #include <fmt/format.h>
 
-#include "remapExecutable.h"
-
 
 namespace DB
 {
@@ -136,10 +136,11 @@ __attribute__((__noinline__)) void remapToHugeStep1(void * begin, size_t size)
 }
 
 
-void remapExecutable()
+size_t remapExecutable()
 {
     auto [begin, size] = getMappedArea(reinterpret_cast<void *>(remapExecutable));
     remapToHugeStep1(begin, size);
+    return size;
 }
 
 }
@@ -149,7 +150,7 @@ void remapExecutable()
 namespace DB
 {
 
-void remapExecutable() {}
+size_t remapExecutable() { return 0; }
 
 }
 
diff --git a/src/Common/remapExecutable.h b/src/Common/remapExecutable.h
index bad5f7adb78..b5af9c82f84 100644
--- a/src/Common/remapExecutable.h
+++ b/src/Common/remapExecutable.h
@@ -1,8 +1,12 @@
 #pragma once
+
+#include <cstdlib>
+
 namespace DB
 {
 
 /// This function tries to reallocate the code of the running program in a more efficient way.
-void remapExecutable();
+/// @return size of remapped area.
+size_t remapExecutable();
 
 }