tree e804faa506bbf9edcfd1fdadb2ab3749f58836cd
parent 8f7b01a178b8e6a7b663a1bbaa1710756d67b69b
author Eric Dumazet <eric.dumazet@gmail.com> 1301929443 +0200
committer Patrick McHardy <kaber@trash.net> 1301929443 +0200

netfilter: get rid of atomic ops in fast path

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 only need the seqcount in it.

Spinlock itself is only locked by the current/owner 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.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>