From: Patrick McHardy <kaber@trash.net>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Netfilter Development Mailinglist
<netfilter-devel@vger.kernel.org>,
netdev <netdev@vger.kernel.org>,
Jesper Dangaard Brouer <hawk@diku.dk>
Subject: Re: [RFC] netfilter: get rid of atomic ops in fast path
Date: Thu, 17 Mar 2011 11:39:01 +0100 [thread overview]
Message-ID: <4D81E4C5.5060009@trash.net> (raw)
In-Reply-To: <1300302005.3202.23.camel@edumazet-laptop>
Am 16.03.2011 20:00, schrieb Eric Dumazet:
> We currently use a percpu spinlock to 'protect' rule bytes/packets
> counters, after various attempts to use RCU instead.
>
> Lately we added a seqlock so that get_counters() can run without
> blocking BH or 'writers'. But we really use the seqcount in it.
>
> Spinlock itself is only locked by the current cpu, so we can remove it
> completely.
>
> This cleanups api, using correct 'writer' vs 'reader' semantic.
>
> At replace time, the get_counters() call makes sure all cpus are done
> using the old table.
>
> We could probably avoid blocking BH (we currently block them in xmit
> path), but thats a different topic ;)
>
> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
> ---
> This is a POC patch (based on net-next-2.6), only handling ip_tables.
> ip6/arp/... need similar changes.
Thanks Eric, this looks good to me.
prev parent reply other threads:[~2011-03-17 10:39 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-16 19:00 [RFC] netfilter: get rid of atomic ops in fast path Eric Dumazet
2011-03-16 20:16 ` David Miller
2011-03-17 10:35 ` [PATCH] netfilter: xtables: fix reentrancy Eric Dumazet
2011-03-17 11:36 ` Jesper Dangaard Brouer
2011-03-17 11:45 ` Eric Dumazet
2011-03-17 13:17 ` Eric Dumazet
2011-03-18 10:27 ` Jesper Dangaard Brouer
2011-03-18 10:50 ` Eric Dumazet
2011-03-17 10:39 ` Patrick McHardy [this message]
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