SPEC CPU2017 Platform Settings for ZTE Systems

Operating System Tuning Parameters

cpupower:

The OS 'cpupower' utility is used to change CPU power governors settings. Available settings are:

• Performance: Run the CPU at the maximum frequency.
• powersave(default): Run the CPU at the minimum frequency.

tuned-adm:

The 'tuned' provides a number of predefined profiles for typical use cases. The 'tuned-adm' command is used to change settings of the tuned daemon. The tuned-adm command can query current settings, list available profiles, recommend a tuning profile for the system, change profiles directly, or turn off tuning. Available profiles are:

• accelerator-performance: Throughput-performance based tuning with disabled higher latency STOP states.
• balanced: General non-specialized tuned profile.
• desktop: Optimize for the desktop use-case.
• hpc-compute: Optimize for HPC compute workloads.
• intel-sst: Configure for Intel Speed Select Base Frequency.
• latency-performance: Optimize for deterministic performance at the cost of increased power consumption.
• network-latency: Optimize for deterministic performance at the cost of increased power consumption, focused on low latency network performance.
• network-throughput: Optimize for streaming network throughput, generally only necessary on older CPUs or 40G+ networks.
• optimize-serial-console: Optimize for serial console use.
• powersave: Optimize for low power consumption.
• throughput-performance: Broadly applicable tuning that provides excellent performance across a variety of common server workloads.
• virtual-guest: Optimize for running inside a virtual guest.
• virtual-host: Optimize for running KVM guests.

nohz_full:

The nohz_full parameter treats the timer ticks of a list of specified CPUs differently. The setting is:

• nohz_full=cpulist: If the CPU is specified as a nohz_full CPU and there is only one runnable task on the CPU, then the kernel stops sending timer ticks to that CPU. As a result, more time may be spent running the application and less time spent servicing interrupts and context switching. The cpu can be specified through the cpulist.

process_specative_off=nospectre_v1=off:

The option "process_specative_off=nospectre_v1=off" is enabled mitigations for Spectre Variant 1, with this option data leakage may be reduced in the system.

tsx_async_abort:

The option "tsx_async_abort" control the TAA mitigations at boot time. TAA allows unprivileged speculative access to data which is available in various CPU internal buffers by using asynchronous aborts within an Intel TSX transactional region. Available settings are:

• off: This option disables the TAA mitigation on affected platforms.
• full: TAA mitigation is enabled. If TSX is enabled, on an affected system it will clear CPU buffers on ring transitions. On systems which are MDS-affected and deploy MDS mitigation, TAA is also mitigated. Specifying this option on those systems will have no effect.
• full,nosmt: The same as tsx_async_abort=full, with SMT disabled on vulnerable CPUs that have TSX enabled. This is the complete mitigation. When TSX is disabled, SMT is not disabled because CPU is not vulnerable to cross-thread TAA attacks.

Firmware / BIOS / Microcode Settings

Intel VT for Directed I/O (VT-d):

Intel Virtualization Technology for Directed I/O (VT-d) by reporting the I/O device assignment to VMM through DMAR ACPI Tables. Values for this BIOS option can be: Enabled/Disabled. Default is Enabled.

Hyper-Threading[ALL]:

Enables Hyper Threading(Software Method to Enable Logical Processor threads. Values for this BIOS option can be: Enabled/Disabled. Default is Enabled.

Turbo Mode:

Enabling this option allows the processor cores to automatically increase its frequency and increasing performance if it is running below power, temperature. The default is "Enabled".

Sub NUMA(SNC):

Sub NUMA Clustering (SNC) is a feature for breaking up the LLC into disjoint clusters based on address range, with each cluster bound to a subset of the memory controllers in the system. It improves average latency to the LLC and is an important pre-requisite to enabling KTI prefetch and is a replacement for the Cluster-on-Die feature found in previous processors. Values for this BIOS option can be: Disable/Enable SNC2 (2-clusters)/Enable SNC4 (4-clusters). Default is Disabled.

SR-IOV Support:

In virtualization, single root input/output virtualization or SR-IOV is a specification that allows the isolation of the PCI Express resources for manageability and performance reasons. A single physical PCI Express can be shared on a virtual environment using the SR-IOV specification. If system has SR-IOV capable PCIe Devices, this option Enables or Disables Single Root IO Virtualization Support. Values for this BIOS option can be: Enabled/Disabled. Default is Enabled.

ENERGY_PERF_BIAS_CFG mode:

This BIOS option allows for processor performance and power optmization. Available settings are:

• Performance: High performance with less need for power saving.
• Balanced Performance (Default Setting): Provides optimal performance efficiency.
• Balanced Power: Provides optimal power efficiency.
• Power: High power saving with less need for performance.

CPU C6 report:

Enable/Disable CPU C6(ACPI C3) report to OS. During the CPU C6 State, the power to all cache is turned off. Current default is Enable.

Patrol Scrub:

This option allows for correction of soft memory errors. Over the length of system runtime, the risk of producing multi-bit and uncorrected errors is reduced with this option. Values for this BIOS setting can be:

• Enabled(default): Correction of soft memory errors can occur during runtime.
• Disabled: Soft memory error correction is turned off during runtime.

LLC dead line alloc:

In the processor non-inclusive cache scheme, MLC evictions are filled into the LLC. When lines are evicted from the MLC, the core can flag them as “dead” (i.e., not likely to be read again). The LLC has the option to drop dead lines and not fill them in the LLC. This can help save space in the LLC and prevent the LLC from evicting useful data. Available settings are:

• Disabled: Disabling this option can save space in the LLC by never moving MLC dead lines into the LLC.
• Enabled(default): Opportunistically move MLC dead lines into the LLC, if space is available.