Re: [patch] lockdep, annotate slocks: turn lockdep off for them

[Herbert Xu <herbert@gondor.apana.org.au>]

On Fri, Jun 30, 2006 at 11:18:50AM +0200, Ingo Molnar wrote:
> 
> Herbert, do the acquire/release semantics as expressed in the 
> lockdep-annotate-slock.patch match sk_lock semantics?

I think it should be fine.
 
> @@ -250,9 +283,18 @@ int sk_receive_skb(struct sock *sk, stru
>  	skb->dev = NULL;
>  
>  	bh_lock_sock(sk);
> -	if (!sock_owned_by_user(sk))
> +	if (!sock_owned_by_user(sk)) {
> +		/*
> +		 * trylock + unlock semantics:
> +		 */
> +		spin_release(&sk->sk_lock.slock.dep_map, 1, _RET_IP_);
> +		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);

Although it would seem that keeping the spin lock would fit the actual
semantics better.  I suppose there must be a technical reason why this
wouldn't work.

Cheers,
-- 
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