Disabling the Transparent Huge Page Function and Using TCMalloc

Purpose

TCMalloc is an efficient memory allocator. It improves the efficiency and performance of memory allocation through a series of optimizations.

• When traditional malloc is allocating and releasing memory, memory fragments occur causing decreased memory usage and insufficient memory. TCMalloc uses fixed-size pages and objects to obtain and allocate memory, reducing memory fragments and improving memory usage.
• TCMalloc applies to multiple-core scenarios and provides stronger support in parallelism. It can set the cache size based on each thread or each CPU to improve parallel performance.
• TCMalloc improves the speed of obtaining memory by caching common objects.
• TCMalloc provides independent cache allocation policy for each thread to reduce lock contention between multiple threads and further optimizes memory allocation efficiency and performance.

Procedure

• Disable the transparent huge page (THP) function.

  1 2	echo never > /sys/kernel/mm/transparent_hugepage/enabled echo never > /sys/kernel/mm/transparent_hugepage/defrag

• Use TCMalloc.

  The following uses MariaDB as an example to describe how to use TCMalloc. In the following commands, replace gperftools-xx with the actual gperftools version.

  1. Download the gperftools source code.

     Download address: https://github.com/gperftools/gperftools/releases

  2. Decompress the gperftools source package.

     1	tar -zxvf gperftools-xx.tar.gz

  3. Go to the gperftools source code directory and perform compilation and installation.

     1 2 3 4

     cd gperftools-xx ./configure --enable-frame-pointers make -j make install

  4. Modify the mysqld_safe file, which is the MariaDB startup script. /usr/local/mysql/bin/mysqld_safe indicates the directory of the mysqld_safe file. Replace the directory with the actual one.
     1. Open the mysqld_safe file.

        1	vim /usr/local/mysql/bin/mysqld_safe

     2. Press i to enter the insert mode. Locate the line under #executing mysqld_safe and add the following content:

        1	export LD_PRELOAD=/usr/local/lib/libtcmalloc.so

     3. Press Esc, type :wq!, and press Enter to save the file and exit.
     4. Restart the MariaDB service for the modification of mysqld_safe to take effect.