feat: flip swap mechanism — MD as primary, RST as override (Phase 1)

This is the first of three phases inverting the per-page swap mechanism
so MD becomes the canonical primary and RST becomes the rare override.

Phase 1 — file renames + conf.py exclude_patterns flip only:
- Rename docs/**/md-<stem>.md to docs/**/<stem>.md (drop md- prefix)
  for all 254 stems previously listed in docs/_swap.txt
- Rename docs/**/<stem>.rst to docs/**/rst-<stem>.rst (add rst- prefix)
  for the same 254 stems
- Repurpose docs/_swap.txt as docs/_rst_overrides.txt; initially empty
  comment-only since no pages need the RST fallback right now
- conf.py exclude_patterns flipped: rst-*.rst is now excluded by default
  instead of md-*.md
- conf.py runtime-artifact references updated to _rst_override_state.json
  and _md_exclude.txt (Phase 2 will rewrite swap_sources.py to produce
  these names; for now no swap script runs because overrides list is empty)

Phase 2 (next commit on this branch) will rewrite scripts/swap_sources.py
with inverted rename direction, delete scripts/import_myst.py + tests, and
update tests/test_swap_sources.py for the new semantics.

Phase 3 will be the cleanup pass and ready-for-review flip.

Generated by robots https://vyos.io

1 files changed, 0 insertions, 208 deletions

diff --git a/docs/vpp/configuration/dataplane/system.rst b/docs/vpp/configuration/dataplane/system.rst
deleted file mode 100644
index 6a2756fd..00000000
--- a/docs/vpp/configuration/dataplane/system.rst
+++ /dev/null
@@ -1,208 +0,0 @@
-:lastproofread: 2026-02-27
-
-.. _vpp_config_system:
-
-.. include:: /_include/need_improvement.txt
-
-##########################
-VyOS Configuration for VPP
-##########################
-
-.. _vpp_config_hugepages:
-.. _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:
-
-.. code-block:: 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'