Messages in this thread | | | Subject | Re: [TOMOYO 05/15](repost) Domain transition handler functions. | From | Peter Zijlstra <> | Date | Wed, 03 Oct 2007 15:24:24 +0200 |
| |
On Wed, 2007-10-03 at 22:04 +0900, Tetsuo Handa wrote: > James Morris wrote: > > I'm pretty sure that the singly linked list idea has been rejected a few > > times. Just use the existing API. > Too bad... > > Well, is there a way to avoid read_lock when reading list? > > Currently, TOMOYO Linux avoids read_lock, on the assumption that > (1) First, ptr->next is initialized with NULL. > (2) Later, ptr->next is assigned non-NULL address. > (3) Assigning to ptr->next is done atomically.
(4) wmb after asigning ptr->next (5) rmb before reading ptr->next
But please do look at the various rcu list primitives. RCU allows one to avoid non-exclusive locks in many cases.
non-exclusive locks are evil, they must all die...
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |