[lkml]   [2010]   [Apr]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH 1/2] rcu: add rcu_access_pointer and rcu_dereference_protect
Le mercredi 07 avril 2010 à 17:19 +0100, David Howells a écrit :

> Why not:
> ASSERT(atomic_read(&sk->sk_wmem_alloc) == 0);
> filter = rcu_dereference(sk->sk_filter);
> This is much clearer, and you're not combining an unrelated assertion with the
> RCU dereference.

1) Because we want the check being done only when CONFIG_PROVE_RCU is

2) Because rcu_dereference() default condition is : 'Am I owning
rcu_read_lock() or equivalent'.
In this context, I am _not_ owning rcu lock, so we will trigger a

So this is best done as is :)

I personally find this very clear and clean, this is why I acked Paul
patch :)

If we were 100% sure testing sk_wmem_alloc is not necessary, we would
have put :

filter = rcu_dereference_check(sk->sk_filter, 1);

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2010-04-07 18:31    [W:0.051 / U:1.132 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site