Re: [PATCH] Remove rcu_assign_pointer() penalty for NULL pointers

2007-11-30 Thread Paul E. McKenney
On Sat, Dec 01, 2007 at 12:07:52PM +1100, Herbert Xu wrote: > On Fri, Nov 30, 2007 at 04:37:21PM -0800, Paul E. McKenney wrote: > > > > The rcu_assign_pointer() primitive currently unconditionally executes > > a memory barrier, even when a NULL pointer is being assigned. This > > has lead some

Re: [PATCH] Remove rcu_assign_pointer() penalty for NULL pointers

2007-11-30 Thread Herbert Xu
On Fri, Nov 30, 2007 at 04:37:21PM -0800, Paul E. McKenney wrote: > > The rcu_assign_pointer() primitive currently unconditionally executes > a memory barrier, even when a NULL pointer is being assigned. This > has lead some to avoid using rcu_assign_pointer() for NULL pointers, > which loses

[PATCH] Remove rcu_assign_pointer() penalty for NULL pointers

2007-11-30 Thread Paul E. McKenney
Hello! The rcu_assign_pointer() primitive currently unconditionally executes a memory barrier, even when a NULL pointer is being assigned. This has lead some to avoid using rcu_assign_pointer() for NULL pointers, which loses the self-documenting advantages of rcu_assign_pointer() This patch uses

Re: [PATCH] Remove rcu_assign_pointer() penalty for NULL pointers

2007-11-30 Thread Herbert Xu
On Fri, Nov 30, 2007 at 04:37:21PM -0800, Paul E. McKenney wrote: The rcu_assign_pointer() primitive currently unconditionally executes a memory barrier, even when a NULL pointer is being assigned. This has lead some to avoid using rcu_assign_pointer() for NULL pointers, which loses the

[PATCH] Remove rcu_assign_pointer() penalty for NULL pointers

2007-11-30 Thread Paul E. McKenney
Hello! The rcu_assign_pointer() primitive currently unconditionally executes a memory barrier, even when a NULL pointer is being assigned. This has lead some to avoid using rcu_assign_pointer() for NULL pointers, which loses the self-documenting advantages of rcu_assign_pointer() This patch uses

Re: [PATCH] Remove rcu_assign_pointer() penalty for NULL pointers

2007-11-30 Thread Paul E. McKenney
On Sat, Dec 01, 2007 at 12:07:52PM +1100, Herbert Xu wrote: On Fri, Nov 30, 2007 at 04:37:21PM -0800, Paul E. McKenney wrote: The rcu_assign_pointer() primitive currently unconditionally executes a memory barrier, even when a NULL pointer is being assigned. This has lead some to avoid