SPEC CPU2017 Platform Settings for Supermicro Systems

Operating System Tuning Parameters

kernel.randomize_va_space (ASLR)
This setting can be used to select the type of process address space randomization. Defaults differ based on whether the architecture supports ASLR, whether the kernel was built with the CONFIG_COMPAT_BRK option or not, or the kernel boot options used.
Possible settings: Disabling ASLR can make process execution more deterministic and runtimes more consistent. For more information see the randomize_va_space entry in the Linux sysctl documentation.
Transparent Hugepages (THP)
THP is an abstraction layer that automates most aspects of creating, managing, and using huge pages. It is designed to hide much of the complexity in using huge pages from system administrators and developers. Huge pages increase the memory page size from 4 kilobytes to 2 megabytes. This provides 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. Most recent Linux OS releases have THP enabled by default.
THP usage is controlled by the sysfs setting /sys/kernel/mm/transparent_hugepage/enabled. Possible values: THP creation is controlled by the sysfs setting /sys/kernel/mm/transparent_hugepage/defrag. Possible values: An application that "always" requests THP often can benefit from waiting for an allocation until those huge pages can be assembled.
For more information see the Linux transparent hugepage documentation.
This is a percentage value of total available memory that can be filled with dirty data before writing the modifications to disk. Set through "sysctl -w vm.dirty_ratio=8".
This control is used to define how aggressive the kernel will swap memory pages. Increaasing the value causes swapping more frequently. The default value is 60. A value of 1 tells the kernel to only swap processes to disk if absolutely necessary. This can be set through a command like "sysctl -w vm.swappiness=1"
Zone_reclaim_mode allows someone to set more or less aggressive approaches to reclaim memory when a zone runs out of memory. It controls whether memory reclaim is performed on a local NUMA node or other nodes. To tell the kernel to free local node memory rather than grabbing free memory from remote nodes, it can be set through a command like "sysctl -w vm.zone_reclaim_mode=1".
Writing this will cause kernel to drop clean caches, as well as reclaimable slab objects like dentries and inodes. Once dropped, their memory becomes free. Set through "sysctl -w vm.drop_caches=3" to free slab objects and pagecache.
CPUFreq scaling governor:

Governors are power schemes for the CPU. It is in-kernel pre-configured power schemes for the CPU and allows you to change the clock speed of the CPUs on the fly. On Linux systems can set the govenor for all CPUs through the cpupower utility with the following command:

Below are govenors in the Linux kernel.


A commandline interface for switching between different tuning profiles available in supported Linux distributions. The distribution provided profiles are located in /usr/lib/tuned and the user defined profiles in /etc/tuned. To set a profile, one can issue the command "tuned-adm profile (profile_name)". Below are details about some relevant profiles.

Firmware / BIOS / Microcode Settings

SMT Control:
This controls enable or disable the logical processor cores on the processor. Enable SMT Control can improve overall performance for most workloads. For some floating point or HPC workloads may result in higher performance if disable SMT Control. Available settings are: