Message-ID: <4B57F421.4070409@zytor.com>
Date: Wed, 20 Jan 2010 22:28:49 -0800
From: "H. Peter Anvin" <hpa@zytor.com>
User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091209 Fedora/3.0-3.fc11 Thunderbird/3.0
MIME-Version: 1.0
To: Linus Torvalds <torvalds@linux-foundation.org>
CC: Christoph Lameter <cl@linux-foundation.org>, Ingo Molnar <mingo@elte.hu>,
       linux-kernel@vger.kernel.org, Andi Kleen <andi@firstfloor.org>
Subject: Re: [x86] Unify semaphore_32.S and rwlock_64.S
References: <alpine.DEB.2.00.1001191616280.28622@router.home> <4B56328E.9080108@zytor.com> <alpine.DEB.2.00.1001201333430.15175@router.home> <4B57641E.5060303@zytor.com> <alpine.DEB.2.00.1001201443340.17915@router.home> <alpine.LFD.2.00.1001201546330.13231@localhost.localdomain> <4B579985.8040504@zytor.com>
In-Reply-To: <4B579985.8040504@zytor.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1123
Lines: 29

On 01/20/2010 04:02 PM, H. Peter Anvin wrote:
> On 01/20/2010 03:57 PM, Linus Torvalds wrote:
>>
> 
> I'm somewhat unhappy about that notion, mostly because it means Yet
> Another Thing To Verify[TM].  I would like to look at the relative code
> sizes of 2^31 and 2^30, however, if all it means is that *one*
> instruction in *one* asm has to be different, I'd rather leave it at 2^31.
> 

Well, there is no size difference within measurable limits (an
x86-64-allyesconfig build is 60(!) bytes larger with 2^31 and the incl,
but that's well within the good luck/bad luck with alignments threshold...)

As such, I'd personally prefer to leave it with 1:31:31:1 split, if
nothing else because it reads a bit tidier to me, despite the minor wart
for the incl trick.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

--
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/