diff options
Diffstat (limited to 'docs/vpp/configuration/dataplane/md-system.md')
| -rw-r--r-- | docs/vpp/configuration/dataplane/md-system.md | 212 |
1 files changed, 0 insertions, 212 deletions
diff --git a/docs/vpp/configuration/dataplane/md-system.md b/docs/vpp/configuration/dataplane/md-system.md deleted file mode 100644 index 51ee8f54..00000000 --- a/docs/vpp/configuration/dataplane/md-system.md +++ /dev/null @@ -1,212 +0,0 @@ ---- -lastproofread: '2026-02-27' ---- - -(vpp_config_system)= - -```{include} /_include/need_improvement.txt -``` - -# VyOS Configuration for VPP - -(vpp-config-hugepages)= - -## Hugepages - -VPP uses hugepages for efficient memory management. Hugepages are larger -memory pages that reduce the overhead of page management and improve -performance for applications that require large amounts of memory. - -Hugepages can be configured in VyOS using the following commands: - -:::{warning} -Changes to hugepage settings require a system reboot to take effect. - -Hugepages must be enabled before VPP configuration is applied. -::: - -To enable hugepages: - -```{cfgcmd} set system option kernel memory hugepage-size \<size\> hugepage-count '\<count\>' -``` - -Enables hugepages with the specified size and count. The size can be either -2MB or 1GB, and the count specifies the number of hugepages to allocate. - -If your system has multiple NUMA nodes, the total amount of hugepages will be -divided equally among them. - -## Resources Limits - -:::{note} -By default, system will calculate and set the recommended values for -resource limits. Avoid tuning these values if you are not sure what you -are doing. -::: - -During operations VPP utilizes a significant amount of system resources, -especially memory. There are two main settings that may need to be -adjusted to ensure VPP runs smoothly: - -Maximum number of memory map areas a process may have: - -```{cfgcmd} set system option resource-limits max-map-count \<value\> -``` - -Maximum shared memory segment size: - -```{cfgcmd} set system option resource-limits shmmax \<value\> -``` - -Both settings are automatically calculated based on configured hugepages. - -## Kernel Tuning - -VPP performance greatly benefits from proper kernel tuning, especially -CPU isolation and disabling unnecessary kernel features. These -optimizations ensure dedicated CPU cores are available exclusively for -VPP dataplane processing without interference from the kernel scheduler -or other system processes. - -:::{warning} -Kernel tuning changes require a system reboot to take effect. - -Improper CPU isolation can lead to system instability if essential -system processes are starved of CPU resources. -::: - -### CPU Isolation and Optimization - -CPU isolation is crucial for VPP performance as it dedicates specific -CPU cores exclusively to VPP dataplane processing. The isolated cores are -removed from the kernel scheduler and will not run regular system -processes. - -**Disable NMI Watchdog** - -The NMI (Non-Maskable Interrupt) watchdog can interfere with VPP -performance by generating interrupts on isolated cores and is not -compatible with nohz-full mode: - -```{cfgcmd} set system option kernel cpu disable-nmi-watchdog - -Disables the NMI watchdog for detecting hard CPU lockups. This -prevents unnecessary interrupts on VPP worker cores. -``` - -**CPU Core Isolation** - -```{cfgcmd} set system option kernel cpu isolate-cpus \<cpu-range\> - -Isolates specified CPUs from the kernel scheduler. Isolated cores will -not run regular system processes and are dedicated to applications like -VPP. - -The ``<cpu-range>`` can be: -* Single core: ``2`` -* Range: ``2-5`` -* Mixed: ``1,3-5,7`` - -:::{important} -Always reserve at least 2 cores for the operating system to ensure -system stability. For example, on a 4-core system, isolate cores -2-3 for VPP and leave cores 0-1 for the OS. - -Assign the first isolated core as the VPP main core and the -remaining isolated cores as VPP worker cores. Ensure that VPP CPU -assignments match the isolated CPU range. -::: -``` - -**Adaptive-Tick Mode** - -```{cfgcmd} set system option kernel cpu nohz-full \<cpu-range\> - -Enables adaptive-tick mode (NO_HZ_FULL) for specified CPUs. This -causes the kernel to avoid sending scheduling-clock interrupts to CPUs -that have only one runnable task, significantly reducing interrupt -overhead for dedicated workloads like VPP. - -Use the same CPU range as configured for ``isolate-cpus``. -``` - -**RCU Callback Offloading** - -```{cfgcmd} set system option kernel cpu rcu-no-cbs \<cpu-range\> - -Offloads Read-Copy-Update (RCU) callback processing from specified -CPUs. This ensures that RCU callbacks do not prevent the specified CPUs -from entering dyntick-idle or adaptive-tick mode, which is essential -for nohz-full functionality. - -Use the same CPU range as configured for ``isolate-cpus``. -``` - -### System Optimization - -Additional kernel optimizations can further improve VPP performance by -disabling unnecessary features and reducing system overhead. - -**Disable High Precision Event Timer** - -```{cfgcmd} set system option kernel disable-hpet - -Disables the High Precision Event Timer (HPET). HPET can cause -additional interrupts and overhead that may impact VPP performance. -``` - -**Disable Machine Check Exceptions** - -```{cfgcmd} set system option kernel disable-mce - -Disables Machine Check Exception (MCE) reporting and handling. While -MCE provides hardware error detection, it can introduce latency in -high-performance scenarios. -``` - -**Disable CPU Power Saving** - -```{cfgcmd} set system option kernel disable-power-saving - -Disables CPU power saving mechanisms (C-states). This keeps CPU cores -at maximum performance levels, eliminating latency from power state -transitions. -``` - -**Disable Soft Lockup Detection** - -```{cfgcmd} set system option kernel disable-softlockup - -Disables the soft lockup detector for kernel threads. This prevents -false positives when VPP worker threads are busy processing packets. -``` - -**Disable CPU Mitigations** - -```{cfgcmd} set system option kernel disable-mitigations - -Disables all optional CPU mitigations for security vulnerabilities -(for example, Spectre, Meltdown). This may improve performance on some -platforms. -``` - -### Optimal Configuration Example - -For a system with 4 CPU cores (0-3) where cores 2-3 are dedicated to VPP: - -```none -# Kernel CPU optimizations -set system option kernel cpu disable-nmi-watchdog -set system option kernel cpu isolate-cpus '2-3' -set system option kernel cpu nohz-full '2-3' -set system option kernel cpu rcu-no-cbs '2-3' - -# System optimizations -set system option kernel disable-hpet -set system option kernel disable-mce -set system option kernel disable-power-saving -set system option kernel disable-softlockup - -# VPP CPU assignment -set vpp settings resource-allocation cpu-cores '2' -``` |