From: David Miller <davem@davemloft.net>
To: casey@schaufler-ca.com
Cc: fw@strlen.de, paul@paul-moore.com, netdev@vger.kernel.org,
linux-security-module@vger.kernel.org, selinux@vger.kernel.org
Subject: Re: New skb extension for use by LSMs (skb "security blob")?
Date: Thu, 22 Aug 2019 15:36:42 -0700 (PDT) [thread overview]
Message-ID: <20190822.153642.10800077338364583.davem@davemloft.net> (raw)
In-Reply-To: <5d524e45-0d80-3a1c-4fd2-7610d2197bf8@schaufler-ca.com>
From: Casey Schaufler <casey@schaufler-ca.com>
Date: Thu, 22 Aug 2019 15:34:44 -0700
> On 8/22/2019 3:28 PM, David Miller wrote:
>> From: Casey Schaufler <casey@schaufler-ca.com>
>> Date: Thu, 22 Aug 2019 14:59:37 -0700
>>
>>> Sure, you *can* do that, but it would be insane to do so.
>> We look up the neighbour table entries on every single packet we
>> transmit from the kernel in the same exact way.
>>
>> And it was exactly to get rid of a pointer in a data structure.
>
> I very much expect that the lifecycle management issues would
> be completely different, but I'll admit to having little understanding
> of the details of the neighbour table.
Neighbour table entries can live anywhere from essentially forever down
to several microseconds.
If your hash is good, and you use RCU locking on the read side, it's a
single pointer dereference in cost.
next prev parent reply other threads:[~2019-08-22 22:36 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-21 22:00 New skb extension for use by LSMs (skb "security blob")? Paul Moore
2019-08-21 22:50 ` David Miller
2019-08-22 3:27 ` Paul Moore
2019-08-22 3:54 ` David Miller
2019-08-22 18:50 ` Casey Schaufler
2019-08-22 7:03 ` Florian Westphal
2019-08-22 16:32 ` Paul Moore
2019-08-22 20:10 ` Casey Schaufler
2019-08-22 20:15 ` Florian Westphal
2019-08-22 20:35 ` Casey Schaufler
2019-08-22 21:18 ` David Miller
2019-08-22 21:59 ` Casey Schaufler
2019-08-22 22:28 ` David Miller
2019-08-22 22:34 ` Casey Schaufler
2019-08-22 22:36 ` David Miller [this message]
2019-08-23 18:56 ` Casey Schaufler
2019-08-22 21:17 ` David Miller
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