Re: [PATCH net-next] docs: net: document neigh gc_interval and gc_stale_time sysctls
From: Jakub Kicinski
Date: Fri Feb 20 2026 - 19:44:05 EST
On Thu, 19 Feb 2026 17:21:58 +0100 Gabriel Goller wrote:
> +neigh/default/gc_interval - INTEGER
> + How often the garbage collector for neighbor entries should run. This
> + value applies to the entire table, not individual entries.
> +
> + Default: 30 seconds
AI suggests that this value is not actually currently used
in our implementation. I can't find any use either, TBH.
It's read and can be written but it's seemingly not used for anything.
> +neigh/default/gc_stale_time - INTEGER
> + Determines how long a neighbor entry can remain unused before it is
> + considered stale and eligible for garbage collection. Entries that have
> + not been used for longer than this time will be removed by the garbage
> + collector, unless they have active references, are marked as PERMANENT,
> + or carry the NTF_EXT_LEARNED or NTF_EXT_VALIDATED flag.
> +
> + Default: 60 seconds
AI adds:
Important caveat: This check is only reached when total_entries >= gc_thresh1
(line 1000-1001). Below that threshold, the periodic GC skips the scan
entirely.
If true I think we should mention that ?
--
pw-bot: cr