From mboxrd@z Thu Jan  1 00:00:00 1970
From: paulmck@linux.vnet.ibm.com (Paul E. McKenney)
Date: Tue, 15 Jun 2010 17:12:28 -0700
Subject: [ltt-dev] [PATCH RFC] Force build failure on unknown
	architectures
In-Reply-To: <4C1812E1.5080103@redhat.com>
References: <20100615231423.GA16064@linux.vnet.ibm.com>
	<4C1812E1.5080103@redhat.com>
Message-ID: <20100616001228.GM2304@linux.vnet.ibm.com>

On Wed, Jun 16, 2010 at 01:55:13AM +0200, Paolo Bonzini wrote:
> On 06/16/2010 01:14 AM, Paul E. McKenney wrote:
> >Create urcu/arch_unknown.h and urcu/uatomic_arch_unknown.h, which
> >contain only #error statements and explanatory comments.  This forces
> >build failures on unrecognized architectures in preference to trying
> >to guess at what operations might be safe on such architectures.
> >
> >One other semi-feasible alternative is to use hashed arrays of locks
> >that are acquired with signals disabled.  However, this seems a bit
> >too ornate, especially for architectures for which the gcc __sync_
> >primitives work correctly.
> 
> ia64 is one.

Does ia64 work with the current code?  (My guess is "no" -- I believe
that you would get build errors.  But I have been surprised before!)

If my guess is correct, my thought would be to create urcu/arch_gcc.h
and urcu/uatomic_arch_gcc.h files with the appropriate definitions
based on __sync_ primitives.  If you can test on IA64, I would also
be happy to add support for it based on these new files.

Or am I missing your point?

							Thanx, Paul