--- /dev/null
+/*
+ * Copyright 2016 Milian Wolff <mail@milianw.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include <malloc.h>
+#include <unistd.h>
+#include <iostream>
+
+using namespace std;
+
+inline void escape(void* p)
+{
+ asm volatile("" : : "g"(p) : "memory");
+}
+
+int main()
+{
+ const auto log2_max = 17;
+ const auto max_steps = log2_max * 2 + 1;
+ unsigned int cost[max_steps];
+ int sizes[max_steps];
+
+ const auto baseline = mallinfo().uordblks;
+
+ for (int i = 1; i < max_steps; ++i) {
+ int size = 1 << i / 2;
+ if (i % 2) {
+ size += size / 2;
+ }
+ sizes[i] = size;
+ auto ptr = malloc(size);
+ escape(ptr); // prevent the compiler from optimizing the malloc away
+ cost[i] = mallinfo().uordblks;
+ free(ptr);
+ }
+
+ cout << "requested\t|\tactual\t|\toverhead\n";
+ for (int i = 1; i < max_steps; ++i) {
+ const auto actual = (cost[i] - baseline);
+ cout << sizes[i] << "\t\t|\t" << actual << "\t|\t" << (actual - sizes[i]) << '\n';
+ }
+ return 0;
+}