SPEC CPU2017 Platform Settings for Peng Cheng Laboratory Platform system

Operating System Tuning Parameters

Install only the relevant files

Select only test related files when installing the operating system,So that many services are not installed, this will reduce the consumption of resources by the operating system itself. In accordance with the following methods to install the operating system: 1.The software installation mode was selected 'Customize now'. 2.Next,In 'base System' column, We choose the following installation package,'Base','Compatibility Libraries', 'Java Platform','Large Systems Performance','Performance Tools','Perl Support'.In 'Development' column, We choose the following installation package,'Development tools'.That is all the installation package.

Cpufreq setting

"cpupower frequency-set" provides a simplified mechanism to adjust processor frequencies when cpu frequency scaling is enabled in the OS. See the cpupower-frequency-set man page for details.Here is a brief description of options used in the config file. By default, settings are applied to all logical cpus in the system.Frequencies can be passed in Hz, kHz (default), MHz, GHz, or THz by postfixing the value with the desired unit name, without any space. Available frequencies and governors can be determined with "cpupower frequency-info".

Tmpfs filesystem setting

Tmpfs is a file system which keeps all files in virtual memory.A tmpfs file system will go to swap if memory pressure demands real memory for applications. This can have a very negative effect on the I/O load and system performance

Process tuning setting

Each process is assigned a time period, known as its time slice, that is the time allowed to run the process. Increse the process time slice can have a positive effect on the calculated sensitivity task. The related kernel parameters are sched_wakeup_granularity_ns, sched_min_granularity_ns, etc.

Transparent Huge Pages

Transparent Hugepages increase the memory page size from 4 kilobytes to 2 megabytes. Transparent Hugepages provide significant performance advantages on systems with highly contended resources and large memory workloads. If memory utilization is too high or memory is badly fragmented which prevents hugepages being allocated, the kernel will assign smaller 4k pages instead.

On RedHat EL6 and later, Transparent Hugepages are used by default if /sys/kernel/mm/transparent_hugepage/enabled is set to always. The default value is always.

On SUSE SLES11 and later, Transparent Hugepages are used by default if /sys/kernel/mm/transparent_hugepage/enabled is set to always. The default value is always.

Kernel Boot Parameter

nohz_full: This kernel option sets adaptive tick mode (NOHZ_FULL) to specified porcessors. Since the number of interrupts is reduced to ones per second, latency-sensitive applications can take advantage of it.


Firmware / BIOS / Microcode Settings

CPU Prefetcher

This BIOS option allows the enabling/disabling of a processor mechanism to prefetch data into the cache according to a pattern-recognition algorithm In some cases, setting this option to Disabled may improve performance. Users should only disable this option after performing application benchmarking to verify improved performance in their environment.

Custom Refresh Rate(Default=32ms)

This BIOS option specifies the memory refresh rate.

Values for this BIOS setting can be:

32ms: specifies the memory refresh rate to 32ms.

64ms: specifies the memory refresh rate to 64ms.

Auto: specifies the memory refresh rate to Auto.Server will changes the memory refresh rate along the temperature of the memory.

Power Policy(Default=Efficiency)

Values for this BIOS setting can be:

Efficiency: Maximize the power efficiency of the server.

Performance: Maximize the performance of the server.

Cooling Configuration

The Baseboard Management Controller allows the user to adjust the fan speed manually,If the server is in a stressful environment, the CPU have high temperature, you can adjust the fan speed to 100%.

Die Interleaving(Default=Disabled)

This BIOS option allows the enabling/disabling of a processor mechanism to contiol the interleaving between CPU DIE. In some cases, setting this option to Disabled may improve performance.

channel Interleaving(Default=Enabled)

This BIOS option allows the enabling/disabling of a processor mechanism to contiol the interleaving between memory channels. In some cases, setting this option to Enabled may improve performance.

Cache Mode(Default=in: partition out: share)

This BIOS option controls the cache mode setting of the controllers.

Values for this BIOS setting can be:

in: partition out: share.Set the controllers L3 cache mode. In chip is set to partitioned mode.Out of chip is set to shared mode.

in: share out: share.In chip is set to shared mode.Out of chip is set to shared mode.

in: private out: share.In chip is set to private mode.Out of chip is set to shared mode.

in: private out: private.In chip is set to private mode.Out of chip is set to private mode.

In some cases, such as the cores of cpu are 196,setting this option to "in: private out: private" may improve performance.

Share mode means the L3 cache is shared by all L2 processes, a process can use the capacity of the entire L3.

Private mode, the entire L3 is divided into N private L3s, each private L3 node only caches the data of the corresponding L2 node, that means a process can only ues part of the L3 capacity.

Partition mode, the entire L3 is divided into N private L3s, each L2 cache accesses its corresponding L3 preferentially, and it can also access the other private L3s.

"N" mentioned above is determined by the CPU cores count, every 4 cores are a cluster sharing one piece private L3 cache.