From: David Ahern <dsahern@gmail.com>
To: Roopa Prabhu <roopa@nvidia.com>, David Ahern <dsahern@kernel.org>,
netdev@vger.kernel.org, kuba@kernel.org, davem@davemloft.net
Cc: Kasper Dupont <kasperd@gjkwv.06.feb.2021.kasperd.net>,
Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Subject: Re: [PATCH net] neighbour: allow NUD_NOARP entries to be forced GCed
Date: Mon, 7 Jun 2021 16:04:47 -0600 [thread overview]
Message-ID: <080b469b-1fb2-dcb6-1a95-7c02918e97c4@gmail.com> (raw)
In-Reply-To: <c704333a-e326-57ba-78e7-1e7111f1e79c@nvidia.com>
On 6/7/21 12:53 PM, Roopa Prabhu wrote:
>
> On 6/7/21 10:35 AM, David Ahern wrote:
>> IFF_POINTOPOINT interfaces use NUD_NOARP entries for IPv6. It's
>> possible to
>> fill up the neighbour table with enough entries that it will overflow for
>> valid connections after that.
>>
>> This behaviour is more prevalent after commit 58956317c8de ("neighbor:
>> Improve garbage collection") is applied, as it prevents removal from
>> entries that are not NUD_FAILED, unless they are more than 5s old.
>>
>> Fixes: 58956317c8de (neighbor: Improve garbage collection)
>> Reported-by: Kasper Dupont <kasperd@gjkwv.06.feb.2021.kasperd.net>
>> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
>> Signed-off-by: David Ahern <dsahern@kernel.org>
>> ---
>> rebased to net tree
>
>
> There are other use-cases that use NUD_NOARP as static neighbour
> entries which should be exempt from forced gc.
>
> for example when qualified by NTF_EXT_LEARNED for the E-VPN use-case.
>
> The check in your patch below should exclude NTF_EXT_LEARNED entries.
>
>
> (unrelated to the neighbour code , but bridge driver also uses
> NUD_NOARP for static entries)
>
>
Maybe I misunderstand your comment: forced_gc does not apply to static
entries; those were moved to a separate list to avoid walking them.
next prev parent reply other threads:[~2021-06-07 22:05 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-07 17:35 [PATCH net] neighbour: allow NUD_NOARP entries to be forced GCed David Ahern
2021-06-07 18:53 ` Roopa Prabhu
2021-06-07 22:04 ` David Ahern [this message]
2021-06-07 22:16 ` Roopa Prabhu
2021-06-07 22:26 ` David Miller
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