Re: [PATCH v1 net-next 4/4] neighbour: Floor INTERVAL_PROBE_TIME_MS at 1000.

On Mon, Oct 12, 2026 at 07:44:59PM +0000, Kuniyuki Iwashima wrote:

Previously, the lower bound of INTERVAL_PROBE_TIME_MS was capped
at 1s by commit ed6cd6a17896 ("net, neigh: Set lower cap for
neigh_managed_work rearming").

Nit: INTERVAL_PROBE_TIME_MS didn't exist in ed6cd6a17896. It was only
introduced later, in 211da42eaa45.

Later, commit 211da42eaa45 ("net, neigh: introduce
interval_probe_time_ms for periodic probe") changed the limit
to 1ms.

The limit actually did not work but was fixed with
netlink_range_validation by commit 6d79b223ec44 ("neighbour:
Enforce min/max to NDTPA_INTERVAL_PROBE_TIME_MS.").

neigh_table is now per-netns, and a user could hog CPU by setting
INTERVAL_PROBE_TIME_MS to a small value.

Let's floor the value at 1 second.

The bot will most likely complain that this changes existing behavior,
but:

1. The original floor was 1 second.

2. It is unlikely that anyone but syzbot is setting it below 1 second.

I would explain this in the commit message to suppress such comments.