Compilation Environment

How to Install OpenJDK?

How to Upgrade CMake?

If the built-in CMake software of the OS cannot meet the database compilation requirements, upgrade CMake as follows (taking CMake 3.5.2 as an example).

Download cmake-3.5.2.tar.gz and upload it to the /home directory on the server.
Decompress the package and go to the extracted directory.
```
tar -zxvf cmake-3.5.2.tar.gz
cd cmake-3.5.2
```
Upgrade CMake.
```
./bootstrap
make -j 96
make install
```
Check the CMake version after the upgrade.
```
/usr/local/bin/cmake --version
```

How to Upgrade GCC?

Generally, the GCC software version provided by the OS is too early and cannot meet software compilation requirements. Therefore, you need to upgrade the GCC version.

For details about how to upgrade GCC, see Installing GCC.

How to Install OpenSSL?

Before installing KAE, you need to install OpenSSL. For details, see Installing OpenSSL.
Before porting open-source components in the Kunpeng BoostKit for CDN scenario, you need to install OpenSSL. For details, see Installing OpenSSL.

How to Configure a Yum Source?

If your environment can access the Internet, you can configure an Internet Yum source. Otherwise, you need to configure a local Yum source. For details about how to configure a Yum source, see Configuring the Yum Source.

How to Disable SMMU?

After the system memory management unit (SMMU) is enabled, the memory access passes through the MMU for address translation, which affects performance. You are advised to disable the SMMU. The disabling procedure is as follows:

During the server reboot, press Delete to access the BIOS, choose Advanced > MISC Config, and press Enter.
Set Support Smmu to Disable.

How to Disable SELinux?

Disabling SELinux may cause security issues. Exercise caution when performing this operation.

Disable SELinux temporarily: setenforce 0

Disable SELinux permanently (requiring a server reboot):

sed -i "s/SELINUX=enforcing/SELINUX=disabled/g" /etc/selinux/config

What Is the Mapping Between BiSheng JDK and OpenJDK Versions?

Currently, BiSheng JDK supports three LTS versions: 8, 11, and 17, which correspond to OpenJDK 8, 11, and 17, respectively.

How to Calculate the Computing Power of a Kunpeng 920 Processor?

The computing power can be measured by the number of operations that can be processed per second. However, this measurement method is common for floating-point operations, not for integer operations.

For integer operations, the computing power can be measured by using a standard test suite such as SPEC CPU.
For floating-point operations, the computing power can be measured by the formula: Computing power of a single chip = Computing power of a single core x Number of cores. A Kunpeng 920 processor has two floating-point pipelines. Given that the double-precision width is 64-bit, the double-precision computing power per core is calculated as follows: 2.6 GHz x 2 pipelines x 1 FMA64 x 2 operations/cycle = 10.4 GFLOPS

Is the Description "Cross NUMA Nodes But Within a Single CPU" Correct?

The description is correct.

The NUMA architecture can be designed within a CPU. For details, see the description and diagram of the NUMA architecture in Kunpeng Processor NUMA Overview in the Top 10 Tips for Performance Tuning.

Where Can I Download YOUR_OS.iso?

YOUR_OS.iso indicates the image package of the OS you are using. You need to obtain the image package from the official website.

For example, if the OS is openEuler 20.03 LTS SP1, the ISO image can be downloaded from link.

How to Calculate the Memory Access Bandwidth and I/O Bandwidth of Kunpeng 920?

The bandwidth of a single memory channel is calculated as follows: Bandwidth = Frequency x Bit width/8

A Kunpeng 920 processor has eight memory channels, and the maximum DDR4 frequency is 3200 MT/s. The theoretical memory bandwidth is 204.8 GB/s (3200 x 64/8 x 8).

For a 2-socket server, the memory bandwidth is 409.6 GB/s (204.8 x 2).

You can use memory bandwidth test tools such as STREAM to test the actual memory bandwidth.