diff options
Diffstat (limited to 'docs/system/options.rst')
| -rw-r--r-- | docs/system/options.rst | 40 |
1 files changed, 38 insertions, 2 deletions
diff --git a/docs/system/options.rst b/docs/system/options.rst index 82ad4801..68f715c0 100644 --- a/docs/system/options.rst +++ b/docs/system/options.rst @@ -6,8 +6,9 @@ Options This chapter describe the possibilities of advanced system behavior. +******* General -####### +******* .. cfgcmd:: set system options beep-if-fully-booted @@ -21,8 +22,9 @@ General Automatically teboot system on kernel panic after 60 seconds. +*********** HTTP client -########### +*********** .. cfgcmd:: set system options http-client source-address <address> @@ -37,3 +39,37 @@ HTTP client .. note:: `source-address` and `source-interface` can not be used at the same time. +*********** +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 + +.. 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. |