Re: [PATCH tip/core/rcu 04/14] rcu: Add a gcc-style structure initializer for RCU pointers

Paul E. McKenney
2012-06-15T21:23:08Z

On Fri, Jun 15, 2012 at 01:48:14PM -0700, Josh Triplett wrote:
> On Fri, Jun 15, 2012 at 01:13:05PM -0700, Paul E. McKenney wrote:
> > From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
> >
> > RCU_INIT_POINTER() returns a value that is never used, and which should
> > be abolished due to terminal ugliness:
> >
> > q = RCU_INIT_POINTER(global_p, p);
> >
> > However, there are two uses that cannot be handled by a do-while
> > formulation because they do gcc-style initialization:
> >
> > RCU_INIT_POINTER(.real_cred, &init_cred),
> > RCU_INIT_POINTER(.cred, &init_cred),
> >
> > This usage is clever, but not necessarily the nicest approach. This
> > commit therefore creates an INIT_RCU_POINTER() macro that is specifically
> > designed for gcc-style initialization.
>
> The concept seems fine, but the names seem entirely non-obvious.
> RCU_INIT_POINTER versus INIT_RCU_POINTER?

I was following things like INIT_THREAD_INFO(), with the leading "INIT_"
for gcc initialization.

Thanx, Paul