SPEC CPU2017 Platform Settings for Lenovo Systems
- sched_cfs_bandwidth_slice_us
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This OS setting controls the amount of run-time(bandwidth) transferred to a run queue from the task's control group bandwidth pool. Small values allow the global bandwidth to be shared in a fine-grained manner among tasks, larger values reduce transfer overhead. The default value is 5000 (ns).
- sched_latency_ns
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This OS setting configures targeted preemption latency for CPU bound tasks. The default value is 24000000 (ns).
- sched_migration_cost_ns
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Amount of time after the last execution that a task is considered to be "cache hot" in migration decisions. A "hot" task is less likely to be migrated to another CPU, so increasing this variable reduces task migrations. The default value is 500000 (ns).
- sched_min_granularity_ns
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This OS setting controls the minimal preemption granularity for CPU bound tasks. As the number of runnable tasks increases, CFS(Complete Fair Scheduler), the scheduler of the Linux kernel, decreases the timeslices of tasks. If the number of runnable tasks exceeds sched_latency_ns/sched_min_granularity_ns, the timeslice becomes number_of_running_tasks * sched_min_granularity_ns. The default value is 8000000 (ns).
- sched_wakeup_granularity_ns
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This OS setting controls the wake-up preemption granularity. Increasing this variable reduces wake-up preemption, reducing disturbance of compute bound tasks. Lowering it improves wake-up latency and throughput for latency critical tasks, particularly when a short duty cycle load component must compete with CPU bound components. The default value is 10000000 (ns).
- numa_balancing
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This OS setting controls automatic NUMA balancing on memory mapping and process placement. Setting 0 disables this feature. It is enabled by default (1).
- IEC Performance Mode: (Default="Performance Mode")
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Acoustic Spec Warning need pay attention to this setting in uEFI setup menu when different configuration. This setting have four option: 2HD Cooling Mode, 4HD Cooling Mode, Performance Mode, Full Speed Mode.
- "2HD Cooling Mode: "When system configuration were CPU *1, HDD *2, 1G Networking Card up to 2 and No Hardware RAID Card, uEFI setup menu can be set to 2HD Cooling Mode.
- "4HD Cooling Mode: "When system configuration were CPU *1, HDD *4, 1G Networking Card up to 2 and Hardware RAID Card *1, uEFI setup menu can be set to 4HD Cooling Mode.
- "Performance Mode: "When system configuration were CPU *1, HDD *4, 10G Networking Card up to 2 and Hardware RAID Card *1, uEFI setup menu can be set to Performance Mode.
- "Full Speed Mode: "Full Speed Mode is not limited in configurations, but when set to this mode, system FANs and CPU FAN will full speed operating and make more acoustic noise.