Date: Wed, 29 Oct 2008 22:22:24 +0200
From: Adrian Bunk <bunk@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Sam Ravnborg <sam@ravnborg.org>, LKML <linux-kernel@vger.kernel.org>,
       Ingo Molnar <mingo@elte.hu>, Frederic Weisbecker <fweisbec@gmail.com>,
       Abhishek Sagar <sagar.abhishek@gmail.com>,
       "David S. Miller" <davem@davemloft.net>,
       Thomas Gleixner <tglx@linutronix.de>,
       Peter Zijlstra <peterz@infradead.org>,
       Andrew Morton <akpm@linux-foundation.org>,
       Linus Torvalds <torvalds@linux-foundation.org>,
       Steven Rostedt <srostedt@redhat.com>
Subject: Re: [PATCH 01/11] ftrace: handle generic arch calls
Message-ID: <20081029202224.GB1816@cs181140183.pp.htv.fi>
References: <20081022184313.179487464@goodmis.org> <20081022185135.618026303@goodmis.org> <alpine.DEB.1.10.0810271337370.8006@gandalf.stny.rr.com> <20081029190045.GC22105@uranus.ravnborg.org> <alpine.DEB.1.10.0810291517220.13214@gandalf.stny.rr.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <alpine.DEB.1.10.0810291517220.13214@gandalf.stny.rr.com>
User-Agent: Mutt/1.5.18 (2008-05-17)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1794
Lines: 57

On Wed, Oct 29, 2008 at 03:24:19PM -0400, Steven Rostedt wrote:
> 
> On Wed, 29 Oct 2008, Sam Ravnborg wrote:
> > >  
> > > +if ($arch eq "x86") {
> > > +    if ($bits == 64) {
> > > +	$arch = "x86_64";
> > > +    } else {
> > > +	$arch = "i386";
> > > +    }
> > > +}
> > > +
> > >  if ($arch eq "x86_64") {
> > >      $section_regex = "Disassembly of section";
> > >      $function_regex = "^([0-9a-fA-F]+)\\s+<(.*?)>:";
> > > 
> > 
> > This looks strange to my eyes.
> > Why not do the more obvious:
> > if ($arch eq "x86" && $bits == 64) {
> > 
> > The change above is like trying to stick to the old i386/x86_64
> > notation.
> 
> Trying to fix it tells me my answer to why I did it his way ;-)
> 
> I have queued patches that will support other archs so x86 is not the
> only arch that can be used here. But x86 is special, it seems to be the 
> only arch (that I know of, correct me if I'm wrong) that can compile with
> multiple archs defined: make ARCH=x86_64, make ARCH=i386, or
> make ARCH=x86. All are legit.
>...

The multiple ARCH settings with different semantics for them are an
x86 curiosity.

But the MIPS, PowerPC and s390 architectures also have unified 
32bit/64bit architectures, so whatever you do will most likely
also be required on these architectures.

> -- Steve

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

--
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/