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Diffstat (limited to 'docs')
| -rw-r--r-- | docs/system/advanced-index.rst | 7 | ||||
| -rw-r--r-- | docs/system/options-performance.rst | 39 |
2 files changed, 43 insertions, 3 deletions
diff --git a/docs/system/advanced-index.rst b/docs/system/advanced-index.rst index 4e9c5699..310dfdb0 100644 --- a/docs/system/advanced-index.rst +++ b/docs/system/advanced-index.rst @@ -1,8 +1,8 @@ .. _advanced_system_tweaks: -###################### -Advanced System Tweaks -###################### +###### +System +###### .. toctree:: :maxdepth: 2 @@ -11,6 +11,7 @@ Advanced System Tweaks flow-accounting ntp options + options-performance boot-options proxy serial-console diff --git a/docs/system/options-performance.rst b/docs/system/options-performance.rst new file mode 100644 index 00000000..32e95520 --- /dev/null +++ b/docs/system/options-performance.rst @@ -0,0 +1,39 @@ +.. _system_options_performance: + +########### +Performance +########### + +As more and more routers run on Hypervisors, expecially with a :abbr:`NOS +(Network Operating System)` as VyOS, it makes fewer and fewer sense to use +static resource bindings like ``smp-affinity`` as present in VyOS 1.2 and +earlier to pin certain interrupt handlers to specific CPUs. + +We now utilize `tuned` for dynamic resource balancing based on profiles. + + .. seealso:: https://access.redhat.com/sites/default/files/attachments/201501-perf-brief-low-latency-tuning-rhel7-v2.1.pdf + +Configureation +============== + +.. cfgcmd:: set system options performance < throughput | latency > + + Configure one of the predefined system performance profiles. + + * ``throughput``: A server profile focused on improving network throughput. + This profile favors performance over power savings by setting ``intel_pstate`` + and ``max_perf_pct=100`` and increasing kernel network buffer sizes. + + It enables transparent huge pages, and uses cpupower to set the performance + cpufreq governor. It also sets ``kernel.sched_min_granularity_ns`` to 10 us, + ``kernel.sched_wakeup_granularity_ns`` to 15 uss, and ``vm.dirty_ratio`` to + 40%. + + * ``latency``: A server profile focused on lowering network latency. + This profile favors performance over power savings by setting ``intel_pstate`` + and ``min_perf_pct=100``. + + It disables transparent huge pages, and automatic NUMA balancing. It also + uses cpupower to set the performance cpufreq governor, and requests a + cpu_dma_latency value of 1. It also sets busy_read and busy_poll times to + 50 us, and tcp_fastopen to 3. |