From: Ido Schimmel <idosch@nvidia.com>
To: Kuniyuki Iwashima <kuniyu@google.com>
Cc: "David S . Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@kernel.org>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
David Ahern <dsahern@kernel.org>, Simon Horman <horms@kernel.org>,
Kuniyuki Iwashima <kuni1840@gmail.com>,
netdev@vger.kernel.org
Subject: Re: [PATCH v1 net-next 4/4] neighbour: Floor INTERVAL_PROBE_TIME_MS at 1000.
Date: Tue, 13 Oct 2026 10:16:19 +0300 [thread overview]
Message-ID: <20261013071619.GB852441@shredder> (raw)
In-Reply-To: <20261012194530.3751034-5-kuniyu@google.com>
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.
next prev parent reply other threads:[~2026-10-13 7:16 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-12 19:44 [PATCH v1 net-next 0/4] neighbour: Misc follow-ups on per-netns neigh_table series Kuniyuki Iwashima
2026-10-12 19:44 ` [PATCH v1 net-next 1/4] Documentation: networking: switchdev: Replace arp_tbl with arp_table(net) Kuniyuki Iwashima
2026-10-12 19:44 ` [PATCH v1 net-next 2/4] selftests: netfilter: Set gc_thresh[123] for gw netns in nft_nat_zones.sh Kuniyuki Iwashima
2026-10-13 20:00 ` netdev-bot+sashiko
2026-10-12 19:44 ` [PATCH v1 net-next 3/4] neighbour: Schedule neigh_managed_work only when needed Kuniyuki Iwashima
2026-10-12 19:44 ` [PATCH v1 net-next 4/4] neighbour: Floor INTERVAL_PROBE_TIME_MS at 1000 Kuniyuki Iwashima
2026-10-13 7:16 ` Ido Schimmel [this message]
2026-10-13 7:27 ` Kuniyuki Iwashima
2026-10-13 20:00 ` netdev-bot+sashiko
2026-10-13 20:29 ` Kuniyuki Iwashima
2026-10-13 20:30 ` Kuniyuki Iwashima
2026-10-13 7:00 ` [PATCH v1 net-next 0/4] neighbour: Misc follow-ups on per-netns neigh_table series Ido Schimmel
2026-10-13 7:23 ` Kuniyuki Iwashima
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