Re: [PATCH net-next-2.6] ipip: get rid of ipip_lock

[Eric Dumazet <eric.dumazet@gmail.com>]

Le mercredi 15 septembre 2010 à 19:28 +0200, Eric Dumazet a écrit :
> As RTNL is held while doing tunnels inserts and deletes, we can remove
> ipip_lock spinlock. My initial RCU conversion was conservative and
> converted the rwlock to spinlock, with no RTNL requirement.
> 
> Use appropriate rcu annotations and modern lockdep checks as well.
> 
> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>

While doing ip_gre conversion, I realize I should define a new helper

/**
 * rtnl_dereference - rcu_dereference with debug checking
 * @p: The pointer to read, prior to dereferencing
 *
 * Do an rcu_dereference(p), but check caller holds RTNL
 */
#define rtnl_dereference(p)					\
	rcu_dereference_check(p, lockdep_rtnl_is_held())



I'll submit a patch serie :

1/3) net: add rtnl_dereference
2/3) ipip: get rid of ipip_lock
3/3) gre: get rid of ipgre_lock

Thanks