OS Tuning
ulimit -s [n | unlimited] (Linux)
Set the stack size to n kbytes, or unlimited to allow the stack size to grow without limit.
Zone Reclaim:
Zone reclaim allows the reclaiming of pages from a zone if the number of free pages falls below a watermark even if other zones still have enough pages available. Reclaiming a page can be more beneficial than taking the performance penalties that are associated with allocating a page on a remote zone, especially for NUMA machines.
Performance Governors (Linux)
In-kernel CPU frequency governors are pre-configured power schemes for the CPU. The CPUfreq governors use P-states to change frequencies and lower power consumption. The dynamic governors can switch between CPU frequencies, based on CPU utilization to allow for power savings while not sacrificing performance.
To set the governor, use the following commmand: "cpupower frequency-set -r -g {desired_governor}"
Disabling Linux services.
The following Linux services were disabled to minimize tasks that may consume CPU cycles:
irqbalance
Disabled through "service irqbalance stop". Depending on the workload involved, the irqbalance service reassigns various IRQ's to system CPUs. Though this service might help in some situations, disabling it can also help environments which need to minimize or eliminate latency to more quickly respond to events.
numa_balancing
Disabled through "echo 0 > /proc/sys/kernel/numa_balancing". This feature will automatically migrate data on demand so memory nodes are aligned to the local CPU that is accessing data. Depending on the workload involved, enabling this can boost the performance if the workload performs well on NUMA hardware. If the workload is statically set to balance between nodes, then this service may not provide a benefit.
Tuning Kernel parameters.
The following Linux Kernel parameters were tuned to better optimize performance of some areas of the system:
vm.dirty_background_ratio
Set through "echo 40 > /proc/sys/vm/dirty_background_ratio". This setting can help Linux disk caching and performance by setting the percentage of system memory that can be filled with dirty pages.
vm.dirty_ratio
Set through "echo 40 > /proc/sys/vm/dirty_ratio". This setting is the absolute maximum amount of system memory that can be filled with dirty pages before everything must get committed to disk.
Firmware Settings
One or more of the following settings may have been set. If so, the "Platform Notes" section of the report will say so; and you can read below to find out more about what these settings mean.
AMD SMT Option (Default = Enabled):
This feature allows enabling or disabling of logical processor cores on processors supporting AMD SMT. When enabled, each physical processor core operates as two logical processor cores. When disabled, each physical core operates as only one logical processor core. Enabling this option can improve overall performance for applications that benefit from a higher processor core count.
Thermal Configuration (Default = Optimal Cooling):
This feature allows the user to select the fan cooling solution for the system. Values for this BIOS option can be:
Performance Determinism (Default = Performance Deterministic):
This option allows the processor to use a given performance level as the max cap, or to let the processor operate as close to the thermal design point (TDP) as possible. Values for this BIOS option can be:
Processor Power and Utilization Monitoring (Default = Enabled):
This BIOS option allows the enabling/disabling of iLo Processor State Mode Switching and Insight Power Management Processor Utilization Monitoring.
When set to disabled, the system will also set the Power Regulator mode to Static High Performance mode and the HP Power Profile mode to Custom. This option may be useful in some environments that require absolute minimum latency.
Workload Profile (Default = General Power Efficient Compute):
This option allows a user to choose a workload profile that best fits the user`s needs. The workload profiles control many power and performance settings that are relevant to general workload areas. Values for this BIOS option can be:
Minimum Processor Idle Power Core C-State (Default = C6 State):
This option can only be configured if the Workload Profile is set to Custom, or this option is not a dependent value for the Workload Profile. This feature selects the processor's lowest idle power state (C-state) that the operating system uses. The higher the C-state, the lower the power usage of that idle state (C6 is the lowest power idle state supported by the processor). Values for this setting can be:
Memory Patrol Scrubbing (Default = Enabled):
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:
First created October 30, 2017.