From mboxrd@z Thu Jan  1 00:00:00 1970
From: paulmck@linux.vnet.ibm.com (Paul E. McKenney)
Date: Wed, 16 Jun 2010 08:53:51 -0700
Subject: [ltt-dev] [PATCH RFC] Force build failure on unknown
	architectures
In-Reply-To: <20100616134651.GC25401@Krystal>
References: <20100615231423.GA16064@linux.vnet.ibm.com>
	<4C1812E1.5080103@redhat.com>
	<20100616001228.GM2304@linux.vnet.ibm.com>
	<4C18C236.3030100@redhat.com> <20100616134651.GC25401@Krystal>
Message-ID: <20100616155351.GB2457@linux.vnet.ibm.com>

On Wed, Jun 16, 2010 at 09:46:52AM -0400, Mathieu Desnoyers wrote:
> * Paolo Bonzini (pbonzini at redhat.com) wrote:
> > On 06/16/2010 02:12 AM, Paul E. McKenney wrote:
> >> 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!)
> >
> > I don't know. :)
> >
> >> 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.
> >
> > Sure, thanks!
> 
> So given the #error on unknown removes ia64 support, I'll wait for a patch
> resend before I merge this patch along with the "gcc-based" ia64 support. Is
> that OK ? So Paul, could you resend this patch along with the ia64 support based
> on gcc ?

Sounds good -- I will rebase everything against current origin/master
and resend.

							Thanx, Paul